A 52-year-old Caucasian man presents to the clinic for evaluation of a mole on his back that he finds concerning. He states that his wife noticed the lesion and believes that it has been getting larger. On inspection, the lesion is 10 mm in diameter with irregular borders. A biopsy is performed. Pathology reveals abnormal melanocytes forming nests at the dermo-epidermal junction and discohesive cell growth into the epidermis. What is the most likely diagnosis?
Q182
A 55-year-old man comes to the physician for a routine health visit. He feels well except for occasional left-sided abdominal discomfort and left shoulder pain. He has smoked 1 pack of cigarettes daily for 20 years. He does not drink alcohol. His pulse is 85/min and his blood pressure is 130/70 mmHg. Examination shows a soft, nontender abdomen. The spleen is palpated 5 cm below the costal margin. There is no lymphadenopathy present. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 12.2 g/dL
Hematocrit 36 %
Leukocyte count 34,000/mm3
Platelet count 450,000/mm3
Cytogenetic testing of his blood cells is pending. Further evaluation of this patient is most likely to show which of the following findings?
Q183
A 35-year-old male presents to his physician with the complaint of fatigue and weakness for six months. His physician orders a CBC which demonstrates anemia and thrombocytopenia. During the subsequent work up, a bone marrow biopsy is performed which ultimately leads to the diagnosis of acute promyelocytic leukemia. Which of the following translocations and fusion genes would be present in this patient?
Q184
A 70-year-old man is brought to the emergency department by his wife because of lethargy, confusion, and nausea for the past 2 days. He has previously been healthy and has no past medical history. His only medications are a daily multivitamin and acetaminophen, which he takes daily for hip pain. Vital signs are within normal limits. He is disoriented to place and time but recognizes his wife. The remainder of his physical examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 9.1 g/dL, a serum calcium concentration of 14.7 mg/dL, and a serum creatinine of 2.2 mg/dL (previously 0.9 mg/dL). Which of the following is the most likely underlying mechanism of this patient's condition?
Q185
A 93-year-old woman is brought to the physician because of a purple area on her right arm that has been growing for one month. She has not had any pain or itching of the area. She has hyperlipidemia, a history of basal cell carcinoma treated with Mohs surgery 2 years ago, and a history of invasive ductal carcinoma of the right breast treated with radical mastectomy 57 years ago. She has had chronic lymphedema of the right upper extremity since the mastectomy. Her only medication is simvastatin. She lives in an assisted living facility. She is content with her living arrangement but feels guilty that she is dependent on others. Vital signs are within normal limits. Physical examination shows extensive edema of the right arm. Skin exam of the proximal upper right extremity shows three coalescing, 0.5–1.0 cm heterogeneous, purple-colored plaques with associated ulceration. Which of the following is the most likely diagnosis?
Q186
A 41-year-old woman presents with occasional dyspareunia and vaginal bleeding after a sexual encounter. She is in a monogamous relationship and uses oral contraception. She does not have a family history of gynecologic malignancies. She has smoked 1 pack of cigarettes per day for 15 years and drinks several glasses of wine daily. She has not received HPV vaccination. Her blood pressure is 120/70 mm Hg, heart rate is 71/min, respiratory rate is 14/min, and temperature is 36.7°C (98.1°F). A speculum examination shows a nulliparous cervix in the mid-plane of the vaginal vault with a red discoloration—approx. 1 × 2 cm in diameter. Bimanual examination revealed no apparent pathologic changes. A Papanicolaou smear is shown in the exhibit. Which of the following proteins is most likely to be inactivated by viral oncoproteins in the affected cells in this case?
Q187
A 53-year-old woman presents to her primary care physician in order to discuss the results of a biopsy. Two weeks ago, her mammogram revealed the presence of suspicious calcifications in her right breast, and she subsequently underwent biopsy of these lesions. Histology of the lesions revealed poorly cohesive cells growing in sheets with a nuclear to cytoplasmic ratio of 1:1. Furthermore, these cells were found to undergo invasion into the surrounding tissues. Given these findings, the patient is referred to an oncologist for further evaluation. Upon further imaging, the patient is found to have no lymph node adenopathy and no distant site metastases. Which of the following would most properly describe the lesions found in this patient?
Q188
A 49-year-old woman comes to the physician with a 2-month history of mild abdominal pain, nausea, and several episodes of vomiting. She often feels full after eating only a small amount of food. Abdominal examination shows mild right upper quadrant tenderness and a liver span of 16 cm. Ultrasonography shows a 5 x 4 cm hyperechoic mass in the left lobe of the liver. The mass is surgically excised. A photomicrograph of the resected specimen is shown. Which of the following is the most likely diagnosis?
Q189
A 74-year-old male presents to his primary care physician complaining of left lower back pain. He reports a four-month history of worsening left flank pain. More recently, he has started to notice that his urine appears brown. His past medical history is notable for gout, hypertension, hyperlipidemia, and myocardial infarction status-post stent placement. He has a 45 pack-year smoking history and drinks 2-3 alcoholic beverages per day. His temperature is 100.9°F (38.3°C), blood pressure is 145/80 mmHg, pulse is 105/min, and respirations are 20/min. Physical examination is notable for left costovertebral angle tenderness. A CT of this patient’s abdomen is shown in figure A. This lesion most likely arose from which of the following cells?
Q190
A 51-year-old woman presents with the following significant and unintentional weight loss. She denies any personal history of blood clots in her past, but she says that her mother has also had to be treated for pulmonary embolism in the recent past. She also mentions that she had been struggling with her weight, so she was initially content with losing the weight, but her daughter convinced her to come to the office to be checked out. Her past medical history is significant for preeclampsia, hypertension, polycystic ovarian syndrome, and hypercholesterolemia. She currently smokes 1 pack of cigarettes per day, drinks a glass of wine per day, and she currently denies any illicit drug use, although she has a remote past of injection drug use with heroin. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 111/min and irregular, and respiratory rate 17/min. On physical examination, her pulses are bounding and complexion is pale, but breath sounds remain clear. Oxygen saturation was initially 91% on room air and electrocardiogram (ECG) showed atrial fibrillation. Upon further discussion with the patient, her physician discovers that she is having some cognitive difficulty. Her leukocyte count is elevated to 128,000/mm3, and she has elevated lactate dehydrogenase (LDH), uric acid, and B-12 levels. A BCR-ABL translocation is present, as evidenced by the Philadelphia chromosome. What is the most likely diagnosis for this patient?
Neoplasia US Medical PG Practice Questions and MCQs
Question 181: A 52-year-old Caucasian man presents to the clinic for evaluation of a mole on his back that he finds concerning. He states that his wife noticed the lesion and believes that it has been getting larger. On inspection, the lesion is 10 mm in diameter with irregular borders. A biopsy is performed. Pathology reveals abnormal melanocytes forming nests at the dermo-epidermal junction and discohesive cell growth into the epidermis. What is the most likely diagnosis?
A. Desmoplastic melanoma
B. Lentigo maligna melanoma
C. Superficial spreading melanoma (Correct Answer)
D. Nodular melanoma
E. Acral lentiginous melanoma
Explanation: ***Superficial spreading melanoma***
- This is the **most common type of melanoma**, accounting for 70% of cases, and typically presents with a **radial growth phase** showing irregular borders and enlarging size.
- Histopathology revealing **nests of abnormal melanocytes at the dermo-epidermal junction** and **discohesive cell growth into the epidermis** (pagetoid spread) is characteristic of superficial spreading melanoma.
*Desmoplastic melanoma*
- Characterized by **fibrous stroma** and often **neural invasion**, with a less pigmented appearance, which is not described.
- Typically presents as a firm, often amelanotic nodule, and can be more aggressive.
*Lentigo maligna melanoma*
- Primarily found in **chronically sun-damaged areas** of the elderly, often on the face, and begins as a flat, tan-brown macule that slowly enlarges.
- Histologically, it shows **atypical melanocytes along the basal layer** of a thinned epidermis, not necessarily forming nests or extensive discohesive growth into the epidermis early on.
*Nodular melanoma*
- This type of melanoma has a **vertical growth phase from the outset**, appearing as a rapidly growing, dark, elevated lesion without a significant preceding radial growth phase.
- Histologically, it involves a substantial dermal component with **minimal or absent intraepidermal radial growth**.
*Acral lentiginous melanoma*
- Occurs on the **palms, soles, or under the nails (subungual)**, and is less associated with sun exposure, often presenting as a dark, spreading lesion.
- Its histological features involve **lentiginous proliferation of atypical melanocytes** along the dermo-epidermal junction with spread into the rete ridges in an acral distribution.
Question 182: A 55-year-old man comes to the physician for a routine health visit. He feels well except for occasional left-sided abdominal discomfort and left shoulder pain. He has smoked 1 pack of cigarettes daily for 20 years. He does not drink alcohol. His pulse is 85/min and his blood pressure is 130/70 mmHg. Examination shows a soft, nontender abdomen. The spleen is palpated 5 cm below the costal margin. There is no lymphadenopathy present. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 12.2 g/dL
Hematocrit 36 %
Leukocyte count 34,000/mm3
Platelet count 450,000/mm3
Cytogenetic testing of his blood cells is pending. Further evaluation of this patient is most likely to show which of the following findings?
A. Autoimmune hemolytic anemia
B. Elevated serum β2 microglobulin
C. Elevated serum calcium
D. Decreased basophil count
E. Low leukocyte alkaline phosphatase score (Correct Answer)
Explanation: ***Low leukocyte alkaline phosphatase score***
- The patient's presentation with **splenomegaly**, **leukocytosis** (34,000/mm³), and a normal hemoglobin/platelet count, strongly suggests a **myeloproliferative neoplasm**, specifically **chronic myeloid leukemia (CML)**.
- A **low leukocyte alkaline phosphatase (LAP) score** is a classic diagnostic feature of CML, as the neutrophils in CML have decreased LAP activity.
*Autoimmune hemolytic anemia*
- This condition is characterized by **anemia** and signs of **hemolysis**, such as elevated reticulocytes and lactate dehydrogenase, which are not described.
- While anemia is present, the primary issue indicated by the high leukocyte count and splenomegaly is a myeloproliferative disorder, not solely autoimmune hemolysis.
*Elevated serum β2 microglobulin*
- Elevated **β2 microglobulin** is a marker of **lymphocytic proliferation** and is commonly seen in conditions like **multiple myeloma** or **lymphoma**.
- The patient's dominant features of **marked leukocytosis** and **splenomegaly** are more consistent with a myeloid disorder than a lymphoid one.
*Elevated serum calcium*
- **Hypercalcemia** is a common complication of **multiple myeloma** or certain **carcinomas** due to bone destruction or paraneoplastic syndromes.
- The patient's symptoms and lab findings (especially high leukocyte count and splenomegaly) do not point to these conditions.
*Decreased basophil count*
- In conditions like **CML**, an **elevated basophil count** is often observed, which contradicts the option of a decreased basophil count.
- Other myeloproliferative neoplasms can also have varying basophil counts, but a decrease is not a hallmark.
Question 183: A 35-year-old male presents to his physician with the complaint of fatigue and weakness for six months. His physician orders a CBC which demonstrates anemia and thrombocytopenia. During the subsequent work up, a bone marrow biopsy is performed which ultimately leads to the diagnosis of acute promyelocytic leukemia. Which of the following translocations and fusion genes would be present in this patient?
A. t(15;17) - PML/RARalpha (Correct Answer)
B. t(9;22) - PML/RARalpha
C. t(9;22) - BCR/Abl1
D. t(14;18) - PML/RARalpha
E. t(8;14) - BCR/Abl1
Explanation: ***t(15;17) - PML/RARalpha***
- **Acute Promyelocytic Leukemia (APL)** is uniquely characterized by the **t(15;17) translocation**, which fuses the **PML (promyelocytic leukemia)** gene on chromosome 15 with the **RARalpha (retinoic acid receptor alpha)** gene on chromosome 17.
- This specific genetic alteration is crucial for diagnosis and dictates treatment with **all-trans retinoic acid (ATRA)**, which targets the aberrant RARalpha fusion protein.
*t(9;22) - PML/RARalpha*
- The **t(9;22) translocation** is associated with **Chronic Myeloid Leukemia (CML)**, forming the **BCR-ABL1 fusion gene**, not PML/RARalpha.
- This option incorrectly pairs the translocation with a fusion gene specific to APL.
*t(9;22) - BCR/Abl1*
- While **t(9;22)** and the **BCR/Abl1 fusion gene** are correctly paired, this is the hallmark of **Chronic Myeloid Leukemia (CML)**, not acute promyelocytic leukemia.
- CML typically presents with a different clinical picture and bone marrow findings than APL, primarily **leukocytosis with a left shift** and **basophilia**.
*t(14;18) - PML/RARalpha*
- The **t(14;18) translocation** is characteristic of **follicular lymphoma**, not any form of acute leukemia.
- It results in the overexpression of the **BCL-2 gene**, promoting cell survival, and is not associated with the PML/RARalpha fusion.
*t(8;14) - BCR/Abl1*
- The **t(8;14) translocation** is associated with **Burkitt lymphoma**, leading to the translocation of the **MYC oncogene** close to immunoglobulin heavy chain enhancers.
- This option also incorrectly pairs the translocation with the **BCR/Abl1 fusion gene**, which is characteristic of CML, and is not relevant to APL.
Question 184: A 70-year-old man is brought to the emergency department by his wife because of lethargy, confusion, and nausea for the past 2 days. He has previously been healthy and has no past medical history. His only medications are a daily multivitamin and acetaminophen, which he takes daily for hip pain. Vital signs are within normal limits. He is disoriented to place and time but recognizes his wife. The remainder of his physical examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 9.1 g/dL, a serum calcium concentration of 14.7 mg/dL, and a serum creatinine of 2.2 mg/dL (previously 0.9 mg/dL). Which of the following is the most likely underlying mechanism of this patient's condition?
A. Increased serum levels of 1,25-hydroxyvitamin D
B. Excessive consumption of calcium
C. Excess PTH secretion from parathyroid glands
D. Ectopic PTHrP release
E. Overproliferation of plasma cells (Correct Answer)
Explanation: ***Overproliferation of plasma cells***
- The patient presents with **hypercalcemia** (14.7 mg/dL), acute **kidney injury** (creatinine 2.2 mg/dL from 0.9 mg/dL), and **anemia** (hemoglobin 9.1 g/dL). These three findings, especially in an elderly patient, strongly suggest **multiple myeloma**, which is characterized by the overproliferation of plasma cells in the bone marrow.
- The overproliferation of plasma cells in multiple myeloma leads to the production of **osteoclast-activating factors**, resulting in increased bone resorption and subsequent hypercalcemia.
*Increased serum levels of 1,25-hydroxyvitamin D*
- While **elevated vitamin D levels** can cause hypercalcemia, it typically occurs due to excessive supplementation or granulomatous diseases (e.g., sarcoidosis). There is no history of either in this patient.
- This mechanism would not explain the accompanying **anemia** or **acute kidney injury** (beyond what hypercalcemia itself might induce), which are prominent features here.
*Excessive consumption of calcium*
- **Milk-alkali syndrome**, caused by excessive intake of calcium and absorbable alkali, can lead to hypercalcemia, metabolic alkalosis, and renal insufficiency.
- However, the patient's history does not indicate excessive calcium intake, and this etiology would not typically explain significant **anemia**.
*Excess PTH secretion from parathyroid glands*
- **Primary hyperparathyroidism** results in increased PTH, leading to hypercalcemia and often low or normal phosphate. While it can cause kidney stones and bone issues, it does not typically cause **anemia** or the rapid progression of kidney injury seen here.
- The patient's creatinine has doubled in a short period, which is more suggestive of an acute insult or a systemic disease like myeloma, rather than chronic changes from primary hyperparathyroidism.
*Ectopic PTHrP release*
- **Parathyroid hormone-related protein (PTHrP)** can be ectopically secreted by various malignancies (e.g., squamous cell carcinoma of the lung, renal cell carcinoma), leading to **humoral hypercalcemia of malignancy**.
- While this can cause **hypercalcemia** and related kidney issues, it typically does not directly cause **anemia** in the same way as multiple myeloma, where **bone marrow infiltration** by plasma cells directly suppresses hematopoiesis. The constellation of hypercalcemia, anemia, and acute kidney injury points more specifically to multiple myeloma.
Question 185: A 93-year-old woman is brought to the physician because of a purple area on her right arm that has been growing for one month. She has not had any pain or itching of the area. She has hyperlipidemia, a history of basal cell carcinoma treated with Mohs surgery 2 years ago, and a history of invasive ductal carcinoma of the right breast treated with radical mastectomy 57 years ago. She has had chronic lymphedema of the right upper extremity since the mastectomy. Her only medication is simvastatin. She lives in an assisted living facility. She is content with her living arrangement but feels guilty that she is dependent on others. Vital signs are within normal limits. Physical examination shows extensive edema of the right arm. Skin exam of the proximal upper right extremity shows three coalescing, 0.5–1.0 cm heterogeneous, purple-colored plaques with associated ulceration. Which of the following is the most likely diagnosis?
A. Lymphangiosarcoma (Correct Answer)
B. Cellulitis
C. Thrombophlebitis
D. Kaposi sarcoma
E. Lichen planus
Explanation: ***Lymphangiosarcoma***
- This patient presents with a **purple area** with **ulceration** on an arm affected by chronic **lymphedema** following a mastectomy. This constellation of findings is highly suggestive of **Stewart-Treves syndrome**, which is a rare but aggressive form of angiosarcoma (lymphangiosarcoma) arising in the setting of chronic lymphedema.
- The history of **radical mastectomy 57 years ago** with subsequent **chronic right upper extremity lymphedema** strongly predisposes to this condition, especially given the lack of pain or itching and the progressive nature of the lesion.
*Cellulitis*
- Characterized by **erythema**, **warmth**, **pain**, and **tenderness**, often with fever and systemic symptoms, none of which are described.
- While lymphedema is a risk factor for cellulitis, the description of a **purple, ulcerated plaque** with a duration of one month is inconsistent with acute bacterial infection.
*Thrombophlebitis*
- Typically presents with **pain**, **tenderness**, **erythema**, and a palpable cord-like vein along the course of a superficial vein, which is not described.
- The lesion described is a spreading, **ulcerated plaque**, not a discrete inflamed vein.
*Kaposi sarcoma*
- While it can present with **purple lesions**, Kaposi sarcoma is typically associated with **immunosuppression** (e.g., HIV infection) or certain endemic regions, neither of which is mentioned.
- The strong association with **chronic lymphedema** in this case makes lymphangiosarcoma a more specific diagnosis.
*Lichen planus*
- A chronic inflammatory condition characterized by **pruritic, purple, polygonal, planar papules and plaques (the 6 Ps)**, often with fine white lines (Wickham's striae).
- It does not typically present as a growing, **ulcerated purple plaque** in the setting of chronic lymphedema, and itching is a prominent symptom.
Question 186: A 41-year-old woman presents with occasional dyspareunia and vaginal bleeding after a sexual encounter. She is in a monogamous relationship and uses oral contraception. She does not have a family history of gynecologic malignancies. She has smoked 1 pack of cigarettes per day for 15 years and drinks several glasses of wine daily. She has not received HPV vaccination. Her blood pressure is 120/70 mm Hg, heart rate is 71/min, respiratory rate is 14/min, and temperature is 36.7°C (98.1°F). A speculum examination shows a nulliparous cervix in the mid-plane of the vaginal vault with a red discoloration—approx. 1 × 2 cm in diameter. Bimanual examination revealed no apparent pathologic changes. A Papanicolaou smear is shown in the exhibit. Which of the following proteins is most likely to be inactivated by viral oncoproteins in the affected cells in this case?
A. p53 (Correct Answer)
B. Btk
C. c-Src
D. Myc
E. EGFR
Explanation: ***p53***
- This patient presents with symptoms and risk factors suggestive of **cervical cancer** (vaginal bleeding after intercourse, smoking, no HPV vaccination). The Papanicolaou smear showing **atypical squamous cells** further supports this.
- High-risk human papillomavirus (HPV) strains, particularly HPV-16 and HPV-18, overexpress **viral oncoproteins E6 and E7**. E6 targets and degrades the tumor suppressor protein **p53**, leading to uncontrolled cell proliferation and malignant transformation.
*Btk*
- **Bruton's tyrosine kinase (Btk)** is primarily involved in B-cell development and signaling. Mutations in _Btk_ are associated with **X-linked agammaglobulinemia**, a primary immunodeficiency.
- There is no direct link between mutations in _Btk_ and the pathogenesis of cervical cancer or the symptoms presented.
*c-Src*
- **c-Src** is a proto-oncogene encoding a non-receptor tyrosine kinase involved in cell growth, differentiation, and migration. While its overexpression and activity are implicated in various cancers, it is not the primary target of HPV oncoproteins in cervical cancer.
- Mutations in _c-Src_ itself are less commonly the initiating genetic event in cervical carcinogenesis compared to the downstream effects of HPV E6 and E7 on p53 and Rb.
*Myc*
- **_Myc_** is a proto-oncogene that plays a crucial role in cell cycle progression, apoptosis, and cellular transformation. Its overexpression is found in many cancers.
- While _Myc_ activation can contribute to cervical cancer progression, the primary and most direct mechanism by which high-risk HPV initiates carcinogenesis involves the inactivation of **p53** and **Rb** by E6 and E7, respectively.
*EGFR*
- The **epidermal growth factor receptor (EGFR)** is a transmembrane receptor tyrosine kinase that promotes cell growth and survival. Its overexpression or activating mutations are significant in lung, colorectal, and head and neck cancers, and it can be involved in cervical cancer progression.
- However, **EGFR** is not the primary gene directly targeted for mutation or degradation by the HPV oncoproteins **E6** and **E7** in the initial stages of cervical carcinogenesis; p53 and Rb are the key targets.
Question 187: A 53-year-old woman presents to her primary care physician in order to discuss the results of a biopsy. Two weeks ago, her mammogram revealed the presence of suspicious calcifications in her right breast, and she subsequently underwent biopsy of these lesions. Histology of the lesions revealed poorly cohesive cells growing in sheets with a nuclear to cytoplasmic ratio of 1:1. Furthermore, these cells were found to undergo invasion into the surrounding tissues. Given these findings, the patient is referred to an oncologist for further evaluation. Upon further imaging, the patient is found to have no lymph node adenopathy and no distant site metastases. Which of the following would most properly describe the lesions found in this patient?
A. Low grade and high stage
B. Low grade and low stage
C. High grade and high stage
D. High grade and low stage (Correct Answer)
E. High grade and no stage
Explanation: ***High grade and low stage***
- The description of **poorly cohesive cells** growing in sheets and invading surrounding tissues indicates **high-grade** malignancy, suggesting aggressive cellular features and rapid growth.
- The absence of lymph node adenopathy and distant metastases signifies a **low stage** of cancer, indicating that the disease is localized.
*Low grade and high stage*
- This option is incorrect because the cellular description points to a **high-grade** tumor, not low grade.
- While there are no distant metastases, a tumor invading surrounding tissues is not considered low grade in terms of cellular aggressiveness.
*Low grade and low stage*
- This option is incorrect because the histological findings of **poorly cohesive cells** and **invasion** are characteristic of a **high-grade** tumor.
- A low-grade tumor would typically have well-differentiated cells with minimal anaplasia and less aggressive behavior.
*High grade and high stage*
- This option is incorrect because, despite the tumor being **high grade** (aggressive cellular features), the absence of lymph node involvement and distant metastases indicates a **low stage**.
- A high stage would imply spread to regional lymph nodes or distant sites.
*High grade and no stage*
- This option is incorrect because all cancers receive a stage, even if it's stage 0 or stage I, based on the extent of the disease (TNM classification).
- The tumor, despite being **high grade**, can be accurately staged as **low stage** given the lack of spread.
Question 188: A 49-year-old woman comes to the physician with a 2-month history of mild abdominal pain, nausea, and several episodes of vomiting. She often feels full after eating only a small amount of food. Abdominal examination shows mild right upper quadrant tenderness and a liver span of 16 cm. Ultrasonography shows a 5 x 4 cm hyperechoic mass in the left lobe of the liver. The mass is surgically excised. A photomicrograph of the resected specimen is shown. Which of the following is the most likely diagnosis?
A. Cavernous hemangioma (Correct Answer)
B. Focal nodular hyperplasia
C. Alveolar echinococcosis
D. Angiosarcoma
E. Hepatocellular adenoma
Explanation: ***Cavernous hemangioma***
- The image shows numerous **dilated vascular spaces** filled with blood and lined by a single layer of endothelial cells, surrounded by fibrous septa, characteristic of a **cavernous hemangioma**.
- **Hyperechoic mass** on ultrasound is typical for hemangiomas due to the multiple interfaces between blood and fibrous tissue.
*Focal nodular hyperplasia*
- Characterized by a **central stellate scar** with radiating fibrous septa and abnormal blood vessels, which is not seen in the photomicrograph.
- While it can be hyperechoic, the distinct vascular architecture of a hemangioma is absent.
*Alveolar echinococcosis*
- This is a parasitic infection forming **hydatid cysts**, which would show parasitic structures like hooklets and a germinal layer, not dilated vascular spaces.
- Imaging would typically reveal multiloculated cysts with calcifications.
*Angiosarcoma*
- A highly malignant tumor arising from vascular endothelial cells, characterized by **atypical endothelial cells**, high mitotic activity, and aggressive infiltration.
- The photomicrograph shows benign, well-differentiated endothelial lining without features of malignancy.
*Hepatocellular adenoma*
- Composed of sheets of **hepatocyte-like cells** without normal bile ducts or portal tracts, and often associated with oral contraceptive use.
- The image clearly displays vascular channels rather than hepatocyte proliferation.
Question 189: A 74-year-old male presents to his primary care physician complaining of left lower back pain. He reports a four-month history of worsening left flank pain. More recently, he has started to notice that his urine appears brown. His past medical history is notable for gout, hypertension, hyperlipidemia, and myocardial infarction status-post stent placement. He has a 45 pack-year smoking history and drinks 2-3 alcoholic beverages per day. His temperature is 100.9°F (38.3°C), blood pressure is 145/80 mmHg, pulse is 105/min, and respirations are 20/min. Physical examination is notable for left costovertebral angle tenderness. A CT of this patient’s abdomen is shown in figure A. This lesion most likely arose from which of the following cells?
A. Perirenal adipocytes
B. Mesangial cells
C. Distal convoluted tubule cells
D. Collecting duct epithelial cells
E. Proximal tubule cells (Correct Answer)
Explanation: ***Proximal tubule cells***
- The patient's presentation with **left flank pain**, **hematuria** (brown urine), **fever**, and a **renal mass on CT** in a patient with a significant smoking history is highly suggestive of **renal cell carcinoma**.
- **Clear cell renal cell carcinoma**, the most common type, originates from the **proximal renal tubule epithelial cells**.
*Perirenal adipocytes*
- Tumors arising from **perirenal adipocytes** are typically **lipomas** or **angiomyolipomas**, which are benign and do not usually present with hematuria and fever, nor do they typically look like the mass on CT.
- While angiomyolipomas can occur in the kidney, they are mesenchymal tumors and are not the primary origin of typical renal cell carcinoma.
*Mesangial cells*
- **Mesangial cells** are specialized cells in the **glomerulus** that provide structural support and regulate glomerular filtration.
- Tumors primarily originating from mesangial cells are extremely rare and do not typically lead to the mass effect and symptoms seen in this case.
*Distal convoluted tubule cells*
- While various parts of the nephron can give rise to renal tumors, tumors originating specifically from the **distal convoluted tubule cells** are less common and typically represent different histological subtypes of renal cell carcinoma, such as **chromophobe renal cell carcinoma**, which is less frequent than clear cell.
- The classic presentation points more directly to the proximal tubule origin.
*Collecting duct epithelial cells*
- Tumors originating from the **collecting duct epithelial cells** are known as **collecting duct carcinoma** (or Bellini duct carcinoma).
- This is a rare and aggressive subtype of renal cell carcinoma, typically presenting with a different histological appearance and often a worse prognosis than clear cell carcinoma. The most common origin remains the proximal tubule.
Question 190: A 51-year-old woman presents with the following significant and unintentional weight loss. She denies any personal history of blood clots in her past, but she says that her mother has also had to be treated for pulmonary embolism in the recent past. She also mentions that she had been struggling with her weight, so she was initially content with losing the weight, but her daughter convinced her to come to the office to be checked out. Her past medical history is significant for preeclampsia, hypertension, polycystic ovarian syndrome, and hypercholesterolemia. She currently smokes 1 pack of cigarettes per day, drinks a glass of wine per day, and she currently denies any illicit drug use, although she has a remote past of injection drug use with heroin. The vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 111/min and irregular, and respiratory rate 17/min. On physical examination, her pulses are bounding and complexion is pale, but breath sounds remain clear. Oxygen saturation was initially 91% on room air and electrocardiogram (ECG) showed atrial fibrillation. Upon further discussion with the patient, her physician discovers that she is having some cognitive difficulty. Her leukocyte count is elevated to 128,000/mm3, and she has elevated lactate dehydrogenase (LDH), uric acid, and B-12 levels. A BCR-ABL translocation is present, as evidenced by the Philadelphia chromosome. What is the most likely diagnosis for this patient?
A. Chronic lymphocytic leukemia
B. Hairy cell leukemia
C. Chronic myelogenous leukemia (Correct Answer)
D. Acute lymphocytic leukemia
E. Acute myelogenous leukemia
Explanation: ***Chronic myelogenous leukemia***
- The presence of a **Philadelphia chromosome (BCR-ABL translocation)** is the hallmark genetic abnormality for **chronic myelogenous leukemia (CML)**.
- **Marked leukocytosis** (128,000/mm3) with elevated **LDH, uric acid**, and **B-12 levels** are characteristic findings in CML due to high cell turnover.
*Chronic lymphocytic leukemia*
- This condition is typically associated with **lymphocytosis** rather than such a high total leukocyte count, and it lacks the **Philadelphia chromosome**.
- Patients often experience **generalized lymphadenopathy** and **hepatosplenomegaly**, which are not explicitly mentioned as primary findings.
*Hairy cell leukemia*
- Characterized by **pancytopenia**, **splenomegaly**, and **"hairy" lymphocytes** on blood smear, none of which are described.
- It is not associated with the **Philadelphia chromosome** or such extreme leukocytosis.
*Acute lymphocytic leukemia*
- Presents with a rapid onset, often with symptoms like **bone pain**, **fevers**, and **bleeding**, along with immature lymphocytes (blasts).
- While it can present with high white blood cell counts, the presence of the **Philadelphia chromosome** in this context points more specifically to CML.
*Acute myelogenous leukemia*
- Characterized by the presence of at least **20% myeloblasts** in the bone marrow or peripheral blood.
- While it can manifest with high leukocyte counts, the defining feature of a **Philadelphia chromosome** is not typical, and it generally has a more acute presentation.