A 78-year-old woman presents to the ophthalmologist with complaints of painless, blurry vision that has worsened in the past year. She says that she sees halos around lights, and that she particularly has trouble driving at night because of the glare from headlights. On physical exam, the patient has an absence of a red reflex. What is the most likely pathology that is causing this patient’s visual symptoms?
Q22
A 61-year-old woman presents to a surgical oncologist for consideration of surgical removal of biopsy-confirmed breast cancer. The mass is located in the tail of Spence along the superolateral aspect of the left breast extending into the axilla. The surgical oncologist determines that the optimal treatment for this patient involves radical mastectomy including removal of the axillary lymph nodes. The patient undergoes all appropriate preoperative tests and is cleared for surgery. During the operation, multiple enlarged axillary lymph nodes are present along the superolateral chest wall. While exposing the lymph nodes, the surgeon accidentally nicks a nerve. Which of the following physical examination findings will most likely be seen in this patient following the operation?
Q23
A 62-year-old man comes to the physician for evaluation of an increasing right-sided cheek swelling for 2 years. He has had recurrent right-sided oral ulcers for the past 2 months. He has smoked a pack of cigarettes daily for 30 years. He drinks a beer every night. His temperature is 37.1°C (98.8°F), pulse is 71/min, respirations are 14/min, and blood pressure is 129/83 mm Hg. Examination shows a mild, nontender swelling above the angle of the right jaw. There is no overlying erythema or induration. There are multiple shallow ulcers on the right buccal mucosa and mandibular marginal gingiva. There is no lymphadenopathy. Ultrasound shows a soft tissue mass in the parotid gland. An ultrasound-guided biopsy of the mass confirms the diagnosis of parotid adenoid cystic carcinoma. A right-sided total parotidectomy is scheduled. This patient is at greatest risk for which of the following early complications?
Q24
A 68-year-old woman with chronic idiopathic thrombocytopenic purpura (ITP) presents to her hematologist for routine follow-up. She has been on chronic corticosteroids for her ITP, in addition to several treatments with intravenous immunoglobulin (IVIG) and rituximab. Her labs today reveal a white blood cell count of 8, hematocrit of 35, and platelet count of 14. Given her refractory ITP with persistent thrombocytopenia, her hematologist recommends that she undergo splenectomy. What is the timeline for vaccination against encapsulated organisms and initiation of penicillin prophylaxis for this patient?
Q25
A 64-year-old woman presents to the surgical oncology clinic as a new patient for evaluation of recently diagnosed breast cancer. She has a medical history of type 2 diabetes mellitus for which she takes metformin. Her surgical history is a total knee arthroplasty 7 years ago. Her family history is insignificant. Physical examination is notable for an irregular nodule near the surface of her right breast. Her primary concern today is which surgical approach will be chosen to remove her breast cancer. Which of the following procedures involves the removal of a portion of a breast?
Q26
A 63-year-old man undergoes uncomplicated laparoscopic cholecystectomy for acute cholecystitis and is admitted to the surgical ward for postoperative management. On postoperative day 1, routine laboratory studies reveal an increase in serum creatinine to 1.46 mg/dL from 0.98 mg/dL before the operation; BUN is 37 mg/dL, increased from 18 mg/dL on prior measurement; K is 4.8 mEq/L and CO2 is 19 mEq/L. The patient has an indwelling urinary catheter in place, draining minimal urine over the last few hours. Which of the following is the most appropriate next step in management?
Q27
A 14-year-old boy is brought to the office by his mother with the complaint of increasing bilateral nasal obstruction for the past 5 months. He also complains of continuous bilateral nasal discharge. He adds that he no longer has any sense of smell of foods. Past medical history is significant for growth retardation and chronic bronchitis at the age of 6 years. Anterior rhinoscopy reveals multiple semi-transparent, soft and mobile masses in the middle meatus. Which of the following is the most likely etiology of this patient’s condition?
Q28
Six hours after near-total thyroidectomy for Graves disease, a 58-year-old man has not had any urine output. The surgery was successful and the patient feels well except for slight neck pain. He has type 2 diabetes mellitus and hypertension. His father had autosomal dominant polycystic kidney disease. Prior to the surgery, the patient was taking metformin and lisinopril regularly and ibuprofen as needed for headaches. His current medications include acetaminophen and codeine. His temperature is 36.2°C (97.2°F), pulse is 82/min, and blood pressure is 122/66 mm Hg. Physical examination shows a 7-cm surgical wound on the anterior neck with mild swelling, but no reddening or warmth. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in management?
Q29
A 40-year-old woman comes to the physician because of a 3-month history of a lump on her neck. The lump is mildly painful. She appears healthy. Examination shows a swelling on the left side of her neck that moves on swallowing. Cardiopulmonary examination shows no abnormalities. Her TSH is 3.6 μU/mL. Ultrasound shows a 4.0-cm (1.6-in) hypoechoic mass in the left thyroid lobe. Fine-needle aspiration of the mass shows neoplastic follicular cells. Molecular analysis of the aspirate shows a mutation in the RAS gene. Which of the following is the most appropriate next step in management?
Q30
A 72-year-old man comes to the physician because of a lesion on his eyelid for 6 months. The lesion is not painful or pruritic. He initially dismissed it as a 'skin tag' but the lesion has increased in size over the past 3 months. He has type 2 diabetes mellitus, coronary artery disease, and left hemiplegia from a stroke 3 years ago. Current medications include sitagliptin, metformin, aspirin, and simvastatin. He used to work as a construction contractor and retired 3 years ago. Examination shows a 1-cm (0.4-in) flesh-colored, nodular, nontender lesion with rolled borders. There is no lymphadenopathy. Cardiopulmonary examination shows no abnormalities. Muscle strength is reduced in the left upper and lower extremities. Visual acuity is 20/20. The pupils are equal and reactive to light. A shave biopsy confirms the diagnosis of basal cell carcinoma. Which of the following is the most appropriate next step in management?
Post-op care US Medical PG Practice Questions and MCQs
Question 21: A 78-year-old woman presents to the ophthalmologist with complaints of painless, blurry vision that has worsened in the past year. She says that she sees halos around lights, and that she particularly has trouble driving at night because of the glare from headlights. On physical exam, the patient has an absence of a red reflex. What is the most likely pathology that is causing this patient’s visual symptoms?
A. Optic nerve head damage
B. Degeneration of the retina
C. Neovascularization of the retina
D. Corneal edema
E. Hardening of the lens (Correct Answer)
Explanation: ***Hardening of the lens***
- The combination of **painless, blurry vision**, **halos around lights**, trouble driving at night due to **glare**, and particularly the **absence of a red reflex**, are classic signs of **cataracts**, which are caused by the **hardening and opacification of the lens**.
- This condition is common in elderly individuals, and the opacification of the lens directly leads to the described visual disturbances and prevents the reflection of light back from the retina, hence the absent red reflex.
*Optic nerve head damage*
- **Optic nerve head damage**, often associated with **glaucoma** or **optic neuritis**, typically causes visual field defects, tunnel vision, or acute vision loss, rather than the gradual, diffuse blurring and glare symptoms described.
- While it can lead to vision loss, it does not explain the presence of **halos around lights** or the **absent red reflex**.
*Degeneration of the retina*
- **Retinal degeneration**, such as **macular degeneration**, primarily affects central vision, causing distortion, central scotomas, and difficulty with fine details, but typically does not cause halos or an absent red reflex unless there is significant hemorrhage.
- The **red reflex** would generally remain present, though potentially obscured if posterior structures are extensively damaged.
*Neovascularization of the retina*
- **Retinal neovascularization**, common in **proliferative diabetic retinopathy** or **wet age-related macular degeneration**, can cause blurred vision, floaters, and sudden vision loss due to hemorrhage, but it is not typically associated with **halos around lights** or an **absent red reflex** as the primary presentation.
- The absence of the **red reflex** points to an issue with light transmission through the anterior structures, not just the posterior retina.
*Corneal edema*
- **Corneal edema** can cause blurry vision and halos around lights due to light scattering, but it is often associated with pain, tearing, and conjunctival injection, which are not mentioned in this patient's presentation.
- While it affects light transmission, it does not typically lead to a completely **absent red reflex** in the same way a dense cataract would, and symptoms might fluctuate more.
Question 22: A 61-year-old woman presents to a surgical oncologist for consideration of surgical removal of biopsy-confirmed breast cancer. The mass is located in the tail of Spence along the superolateral aspect of the left breast extending into the axilla. The surgical oncologist determines that the optimal treatment for this patient involves radical mastectomy including removal of the axillary lymph nodes. The patient undergoes all appropriate preoperative tests and is cleared for surgery. During the operation, multiple enlarged axillary lymph nodes are present along the superolateral chest wall. While exposing the lymph nodes, the surgeon accidentally nicks a nerve. Which of the following physical examination findings will most likely be seen in this patient following the operation?
A. Internal rotation, adduction, and extension of the arm
B. Weakness in arm flexion at the elbow and numbness over the lateral forearm
C. Weakness in shoulder abduction and numbness over the lateral shoulder
D. Scapular protrusion while pressing against a wall (Correct Answer)
E. Weakness in wrist extension and numbness over the dorsal hand
Explanation: ***Scapular protrusion while pressing against a wall***
- Damage to the **long thoracic nerve** during axillary dissection (common in radical mastectomy) paralyzes the **serratus anterior muscle**.
- Paralysis of the serratus anterior causes **scapular winging** (protrusion) and inability to effectively protract the scapula, especially when pushing against a wall.
*Internal rotation, adduction, and extension of the arm*
- This constellation of findings, sometimes called **"policeman's tip"**, is characteristic of an **Erb's palsy**, involving the C5-C6 roots of the brachial plexus.
- Erb's palsy typically results from birth trauma or severe shoulder injury, not commonly from axillary lymph node dissection.
*Weakness in arm flexion at the elbow and numbness over the lateral forearm*
- This symptom complex indicates injury to the **musculocutaneous nerve**, affecting the biceps brachii and brachialis muscles and sensation to the lateral forearm.
- While theoretically possible in deep axillary dissection, it is less common than long thoracic nerve injury during routine axillary node removal.
*Weakness in shoulder abduction and numbness over the lateral shoulder*
- This presentation suggests damage to the **axillary nerve**, which innervates the deltoid and teres minor muscles and provides sensation over the "regimental badge" area of the shoulder.
- The axillary nerve is located more inferiorly and posteriorly in the axilla and is less prone to injury during standard anterior axillary lymph node dissection compared to the long thoracic nerve.
*Weakness in wrist extension and numbness over the dorsal hand*
- These are signs of **radial nerve injury**, which affects the extensor muscles of the wrist and fingers and sensation over the dorsal hand.
- The radial nerve runs more posteriorly in the axilla and arm, making it less susceptible to injury during an anterior axillary lymph node dissection.
Question 23: A 62-year-old man comes to the physician for evaluation of an increasing right-sided cheek swelling for 2 years. He has had recurrent right-sided oral ulcers for the past 2 months. He has smoked a pack of cigarettes daily for 30 years. He drinks a beer every night. His temperature is 37.1°C (98.8°F), pulse is 71/min, respirations are 14/min, and blood pressure is 129/83 mm Hg. Examination shows a mild, nontender swelling above the angle of the right jaw. There is no overlying erythema or induration. There are multiple shallow ulcers on the right buccal mucosa and mandibular marginal gingiva. There is no lymphadenopathy. Ultrasound shows a soft tissue mass in the parotid gland. An ultrasound-guided biopsy of the mass confirms the diagnosis of parotid adenoid cystic carcinoma. A right-sided total parotidectomy is scheduled. This patient is at greatest risk for which of the following early complications?
A. Hyperacusis of the right ear
B. Hypoesthesia of the right ear lobe
C. Xerostomia when eating
D. Paralysis of the right lower lip (Correct Answer)
E. Impaired taste and sensation of the posterior 1/3 of the tongue
Explanation: ***Paralysis of the right lower lip***
- A total parotidectomy involves the dissection of the **facial nerve (CN VII)**, which branches within the parotid gland.
- The **marginal mandibular branch of the facial nerve** innervates the muscles that depress the lower lip (e.g., depressor anguli oris, depressor labii inferioris) and is particularly vulnerable during surgery, leading to paralysis and an asymmetric smile.
*Hyperacusis of the right ear*
- Hyperacusis results from damage to the **stapedius muscle** innervation via the **facial nerve's branch to the stapedius**, which would affect the ear's ability to dampen loud sounds.
- While the facial nerve is at risk, this specific branch is typically preserved or its injury does not manifest as a common *early* complication of parotidectomy compared to motor facial nerve branches.
*Hypoesthesia of the right ear lobe*
- **Hypoesthesia** (decreased sensation) or **numbness** of the ear lobe and preauricular area commonly occurs due to injury to the **great auricular nerve**, which provides sensory innervation to this region and is often sacrificed during parotidectomy.
- While this sensory change is a common complication, motor deficits (such as facial nerve injury) are of greater clinical concern as an early complication.
*Xerostomia when eating*
- **Xerostomia** (dry mouth) after parotidectomy can result from damage to the **parasympathetic innervation of the salivary glands**, particularly the auriculotemporal nerve which carries secretomotor fibers to the parotid gland.
- However, this complication primarily refers to a *subjective* feeling of dry mouth, and **Frey's syndrome** (gustatory sweating) is a more specific and common glandular complication related to aberrant reinnervation after parotid surgery.
*Impaired taste and sensation of the posterior 1/3 of the tongue*
- Taste sensation to the posterior one-third of the tongue is carried by the **glossopharyngeal nerve (CN IX)**, which is not directly involved in a parotidectomy.
- Sensation to this area is also primarily glossopharyngeal, and neither is directly within the surgical field for a parotidectomy.
Question 24: A 68-year-old woman with chronic idiopathic thrombocytopenic purpura (ITP) presents to her hematologist for routine follow-up. She has been on chronic corticosteroids for her ITP, in addition to several treatments with intravenous immunoglobulin (IVIG) and rituximab. Her labs today reveal a white blood cell count of 8, hematocrit of 35, and platelet count of 14. Given her refractory ITP with persistent thrombocytopenia, her hematologist recommends that she undergo splenectomy. What is the timeline for vaccination against encapsulated organisms and initiation of penicillin prophylaxis for this patient?
A. Vaccinate: at the time of surgery; Penicillin: at time of surgery for 5 years
B. Vaccinate: 2 weeks prior to surgery; Penicillin: at time of surgery for 5 years (Correct Answer)
C. Vaccinate: 2 weeks prior to surgery; Penicillin: at time of surgery for an indefinite course
D. Vaccinate: 2 weeks prior to surgery; Penicillin: 2 weeks prior to surgery for an indefinite course
E. Vaccinate: at the time of surgery; Penicillin: 2 weeks prior to surgery for an indefinite course
Explanation: **Vaccinate: 2 weeks prior to surgery; Penicillin: at time of surgery for 5 years**
- **Vaccination against encapsulated organisms** (e.g., *Streptococcus pneumoniae*, *Haemophilus influenzae type b*, *Neisseria meningitidis*) should ideally occur **2 weeks prior to splenectomy**. This allows sufficient time for the patient to mount an immune response and develop protective antibodies before the spleen's critical role in filtering blood and producing opsonizing antibodies against these bacteria is removed.
- **Penicillin prophylaxis** should be initiated at the time of surgery and typically continued for **at least 5 years** post-splenectomy, due to the lifelong increased risk of overwhelming post-splenectomy infection (OPSI) by encapsulated bacteria.
*Vaccinate: at the time of surgery; Penicillin: at time of surgery for 5 years*
- Vaccinating at the time of surgery does not allow enough time for the **immune system to mount an effective response** before the spleen's protective function is lost, leaving the patient vulnerable.
- While penicillin prophylaxis for 5 years is appropriate, the timing of vaccination is suboptimal.
*Vaccinate: 2 weeks prior to surgery; Penicillin: at time of surgery for an indefinite course*
- **Vaccinating 2 weeks prior to surgery** is the correct timing for optimal immune response.
- However, **indefinite penicillin prophylaxis** is usually reserved for patients with recurrent infections or other high-risk factors; a 5-year course is typically recommended for most adults after splenectomy.
*Vaccinate: 2 weeks prior to surgery; Penicillin: 2 weeks prior to surgery for an indefinite course*
- While **vaccinating 2 weeks prior to surgery** is correct, starting penicillin prophylaxis before surgery is generally not necessary unless there is an active infection.
- An **indefinite course of penicillin** is not the standard recommendation for all adult splenectomy patients; a 5-year course is more common.
*Vaccinate: at the time of surgery; Penicillin: 2 weeks prior to surgery for an indefinite course*
- **Vaccinating at the time of surgery** does not provide adequate time for the development of protective immunity, making it an incorrect approach.
- Starting **penicillin prophylaxis 2 weeks prior to surgery** is not standard practice, and an indefinite course is typically not recommended unless specific risk factors are present.
Question 25: A 64-year-old woman presents to the surgical oncology clinic as a new patient for evaluation of recently diagnosed breast cancer. She has a medical history of type 2 diabetes mellitus for which she takes metformin. Her surgical history is a total knee arthroplasty 7 years ago. Her family history is insignificant. Physical examination is notable for an irregular nodule near the surface of her right breast. Her primary concern today is which surgical approach will be chosen to remove her breast cancer. Which of the following procedures involves the removal of a portion of a breast?
A. Arthroplasty
B. Lumpectomy (Correct Answer)
C. Vasectomy
D. Mastectomy
E. Laminectomy
Explanation: ***Lumpectomy***
- A **lumpectomy** is a surgical procedure that removes the **breast cancer tumor** and a small margin of surrounding healthy tissue, preserving most of the breast.
- This procedure is a common treatment for early-stage breast cancer and is often followed by radiation therapy.
*Arthroplasty*
- **Arthroplasty** is a surgical procedure to **repair or replace a joint**, typically due to arthritis or injury.
- The patient's history of a total knee arthroplasty indicates this procedure was performed on her knee, not her breast.
*Vasectomy*
- A **vasectomy** is a surgical procedure for **male sterilization**, involving the cutting and sealing of the vas deferens.
- This procedure is unrelated to breast cancer treatment or breast surgery.
*Mastectomy*
- A **mastectomy** involves the **complete surgical removal of the entire breast**, often including the nipple and areola.
- While it is a breast surgery, it removes the *entire* breast, not just a portion.
*Laminectomy*
- A **laminectomy** is a surgical procedure that removes a portion of the **vertebra (lamina)** to relieve pressure on the spinal cord or nerves.
- This procedure is for spinal conditions and is entirely unrelated to breast cancer surgery.
Question 26: A 63-year-old man undergoes uncomplicated laparoscopic cholecystectomy for acute cholecystitis and is admitted to the surgical ward for postoperative management. On postoperative day 1, routine laboratory studies reveal an increase in serum creatinine to 1.46 mg/dL from 0.98 mg/dL before the operation; BUN is 37 mg/dL, increased from 18 mg/dL on prior measurement; K is 4.8 mEq/L and CO2 is 19 mEq/L. The patient has an indwelling urinary catheter in place, draining minimal urine over the last few hours. Which of the following is the most appropriate next step in management?
A. Initiate emergent hemodialysis
B. Obtain bilateral renal ultrasonography
C. Obtain urinalysis
D. Evaluate urinary catheter for obstruction (Correct Answer)
E. Administer IV fluid bolus
Explanation: ***Evaluate urinary catheter for obstruction***
- The patient presents with **acute kidney injury (AKI)** evidenced by elevated BUN and creatinine, along with minimal urine output, raising suspicion for a **post-renal obstruction**.
- Given the presence of an indwelling urinary catheter, a **mechanical obstruction** (e.g., kink, clot) is the most immediate and easily reversible cause to investigate.
*Initiate emergent hemodialysis*
- While the patient has AKI, there are no immediate life-threatening indications for **emergent hemodialysis** such as severe hyperkalemia, refractory acidosis, or pulmonary edema.
- Furthermore, investigating and potentially reversing the cause of AKI should precede considering dialysis.
*Obtain bilateral renal ultrasonography*
- **Renal ultrasonography** is appropriate for evaluating post-renal causes after simpler causes of obstruction, such as a catheter issue, have been ruled out.
- It would be used to assess for hydronephrosis, which indicates **ureteral or bladder outlet obstruction**.
*Obtain urinalysis*
- A **urinalysis** can help characterize intrinsic renal causes of AKI (e.g., ATN, interstitial nephritis) but is less helpful in initial assessment of a suspected acute obstruction related to a catheter.
- The immediate priority is to rule out a mechanical issue with the indwelling catheter.
*Administer IV fluid bolus*
- The patient's BUN/creatinine ratio (approximately 25:1) suggests a potential **pre-renal etiology** (volume depletion), but the minimal urine output with an indwelling catheter warrants ruling out obstruction first.
- Administering fluids without addressing a potential obstruction could worsen patient outcome if the obstruction is present.
Question 27: A 14-year-old boy is brought to the office by his mother with the complaint of increasing bilateral nasal obstruction for the past 5 months. He also complains of continuous bilateral nasal discharge. He adds that he no longer has any sense of smell of foods. Past medical history is significant for growth retardation and chronic bronchitis at the age of 6 years. Anterior rhinoscopy reveals multiple semi-transparent, soft and mobile masses in the middle meatus. Which of the following is the most likely etiology of this patient’s condition?
A. Juvenile nasopharyngeal angiofibroma
B. Nonallergic rhinopathy
C. Septal deviation
D. Foreign body
E. Nasal polyposis (Correct Answer)
Explanation: ***Nasal polyposis***
- The patient's history of **growth retardation** and **chronic bronchitis** at age 6, along with current **nasal obstruction**, **discharge**, and **anosmia**, suggests underlying **cystic fibrosis**, for which nasal polyposis is a common complication.
- The presence of **multiple semi-transparent, soft, mobile masses** in the **middle meatus** is characteristic of nasal polyps.
*Juvenile nasopharyngeal angiofibroma*
- This typically presents in adolescent males with **unilateral nasal obstruction** and **epistaxis**, which are not the primary complaints here.
- While it causes nasal obstruction, the masses are usually **firm, vascular**, and located in the nasopharynx, unlike the soft, bilateral masses described.
*Nonallergic rhinopathy*
- Primarily characterized by **chronic nasal congestion** and watery discharge, often triggered by irritants, but usually **without visible masses** or significant anosmia early on.
- It does not explain the history of growth retardation or chronic bronchitis.
*Septal deviation*
- Causes **unilateral or bilateral nasal obstruction**, but it is a structural abnormality of the septum, not characterized by **mobile, semi-transparent masses** in the middle meatus.
- It would not explain the patient's history of chronic bronchitis or anosmia.
*Foreign body*
- While a foreign body can cause **unilateral nasal obstruction** and discharge, it is more common in younger children and would typically present with a **single object** visible, often with a **foul smell**, not multiple soft masses bilaterally.
- It also wouldn't account for the patient's past medical history of growth retardation and chronic bronchitis.
Question 28: Six hours after near-total thyroidectomy for Graves disease, a 58-year-old man has not had any urine output. The surgery was successful and the patient feels well except for slight neck pain. He has type 2 diabetes mellitus and hypertension. His father had autosomal dominant polycystic kidney disease. Prior to the surgery, the patient was taking metformin and lisinopril regularly and ibuprofen as needed for headaches. His current medications include acetaminophen and codeine. His temperature is 36.2°C (97.2°F), pulse is 82/min, and blood pressure is 122/66 mm Hg. Physical examination shows a 7-cm surgical wound on the anterior neck with mild swelling, but no reddening or warmth. The remainder of the examination shows no abnormalities. Which of the following is the most appropriate next step in management?
A. Obtain renal scintigraphy
B. Perform bedside bladder scan (Correct Answer)
C. Administer furosemide
D. Obtain urinalysis
E. Obtain renal biopsy
Explanation: **Perform bedside bladder scan**
- The absence of urine output post-surgery is concerning for **urinary retention**, especially given the recent surgery and pain medication use. A bedside bladder scan is the quickest and least invasive way to confirm significant bladder distension.
- Postoperative urinary retention can be caused by various factors, including the effects of anesthesia, pain, immobility, and certain medications like opioids, which the patient is currently receiving (codeine).
*Obtain renal scintigraphy*
- **Renal scintigraphy** is used to assess kidney function and blood flow, but it is not the initial test for acute anuria or oligoanuria in the immediate postoperative period.
- This test would be more appropriate if there was suspicion of a vascular compromise to the kidneys or an intrinsic kidney problem, which is not the most likely cause of acute anuria in this clinical context.
*Administer furosemide*
- Administering a loop diuretic like **furosemide** without knowing if the patient has obstructive uropathy or hypovolemia could be harmful.
- If the patient has urinary retention, furosemide would be ineffective and could potentially worsen dehydration if the anuria is due to severe hypovolemia.
*Obtain urinalysis*
- A **urinalysis** evaluates urine sediment and chemical properties, which would be useful for diagnosing intrinsic kidney disease, infection, or nephrolithiasis.
- However, with complete anuria (no urine output), there is no urine to analyze, making this step impractical and unhelpful in determining the immediate cause of no urine output.
*Obtain renal biopsy*
- A **renal biopsy** is an invasive procedure used to diagnose intrinsic kidney diseases. It carries risks and is not an appropriate initial step for acute anuria after surgery.
- It would only be considered if less invasive tests pinpointed a specific intrinsic renal pathology requiring tissue diagnosis, which is far down the diagnostic algorithm for acute anuria.
Question 29: A 40-year-old woman comes to the physician because of a 3-month history of a lump on her neck. The lump is mildly painful. She appears healthy. Examination shows a swelling on the left side of her neck that moves on swallowing. Cardiopulmonary examination shows no abnormalities. Her TSH is 3.6 μU/mL. Ultrasound shows a 4.0-cm (1.6-in) hypoechoic mass in the left thyroid lobe. Fine-needle aspiration of the mass shows neoplastic follicular cells. Molecular analysis of the aspirate shows a mutation in the RAS gene. Which of the following is the most appropriate next step in management?
A. Radioiodine therapy
B. External beam radiation
C. Total thyroidectomy
D. Thyroid lobectomy (Correct Answer)
E. Watchful waiting
Explanation: ***Thyroid lobectomy***
- A **thyroid lobectomy** is appropriate for a **solitary thyroid nodule** with suspicious features (hypoechoic, neoplastic follicular cells, **RAS mutation**) and a size of 4.0 cm, as it allows for pathological diagnosis and treatment while preserving the other lobe.
- The **RAS mutation** indicates a moderate risk of malignancy, and for a unilateral tumor of this size, lobectomy is often preferred over total thyroidectomy as it minimizes the risk of **hypoparathyroidism** and the need for lifelong thyroid hormone replacement.
*Radioiodine therapy*
- This therapy is primarily used as an **adjunctive treatment** after surgical removal of thyroid cancer, especially for **metastatic disease** or **large residual tumors**, not as a primary treatment for a localized tumor before surgery.
- It is also typically reserved for **differentiated thyroid cancers** (papillary, follicular) that have demonstrated uptake, and surgical removal is the initial step for diagnosis and treatment.
*External beam radiation*
- **External beam radiation** is generally reserved for **advanced, inoperable thyroid cancers** or for cases with **extracapsular invasion** or **distant metastases** that are not amenable to radioiodine therapy.
- It carries significant side effects and is not a first-line treatment for an early-stage, localized thyroid nodule.
*Total thyroidectomy*
- **Total thyroidectomy** is indicated for larger thyroid cancers (>4 cm), bilateral disease, or aggressive histological subtypes.
- Given the patient's **unilateral tumor** with a **RAS mutation** (which signifies moderate risk), a thyroid lobectomy is appropriate as the initial surgical approach, with total thyroidectomy reserved if final pathology shows aggressive features.
*Watchful waiting*
- **Watchful waiting** is inappropriate given the presence of **neoplastic follicular cells** and a **RAS mutation**, as these findings indicate a significant risk of malignancy.
- The nodule size of 4.0 cm and molecular findings warrant surgical intervention for definitive diagnosis and treatment rather than observation.
Question 30: A 72-year-old man comes to the physician because of a lesion on his eyelid for 6 months. The lesion is not painful or pruritic. He initially dismissed it as a 'skin tag' but the lesion has increased in size over the past 3 months. He has type 2 diabetes mellitus, coronary artery disease, and left hemiplegia from a stroke 3 years ago. Current medications include sitagliptin, metformin, aspirin, and simvastatin. He used to work as a construction contractor and retired 3 years ago. Examination shows a 1-cm (0.4-in) flesh-colored, nodular, nontender lesion with rolled borders. There is no lymphadenopathy. Cardiopulmonary examination shows no abnormalities. Muscle strength is reduced in the left upper and lower extremities. Visual acuity is 20/20. The pupils are equal and reactive to light. A shave biopsy confirms the diagnosis of basal cell carcinoma. Which of the following is the most appropriate next step in management?
A. Laser ablation
B. Cryotherapy
C. Topical chemotherapy
D. Wide local excision
E. Mohs micrographic surgery (Correct Answer)
Explanation: ***Mohs micrographic surgery***
- The lesion's location on the **eyelid** (a cosmetically and functionally sensitive area), its **nodular appearance** with **rolled borders**, and the likely diagnosis of **basal cell carcinoma (BCC)** make Mohs surgery the most appropriate treatment.
- Mohs surgery offers the highest cure rates for BCCs and preserves the maximum amount of healthy tissue, which is crucial for lesions on the face and eyelids.
*Wide local excision*
- While effective for many skin cancers, **wide local excision** might lead to significant cosmetic or functional defects on the eyelid due to the need for a wider margin of healthy tissue removal.
- Its cure rates are generally lower than Mohs surgery for high-risk BCCs, especially in sensitive areas.
*Laser ablation*
- **Laser ablation** is typically used for superficial or precancerous lesions, not for nodular, invasive basal cell carcinoma.
- It does not allow for histological margin control, which is essential to ensure complete tumor removal and reduce recurrence.
*Cryotherapy*
- **Cryotherapy** is suitable for small, superficial, or pre-malignant lesions, but not for a nodular lesion on the eyelid where tissue preservation and precise margin control are critical.
- It does not offer histological confirmation of clear margins, increasing the risk of recurrence.
*Topical chemotherapy*
- **Topical chemotherapy** (e.g., imiquimod, 5-fluorouracil) is generally reserved for superficial basal cell carcinomas distant from critical structures.
- It is not effective for nodular BCCs and lacks the ability to confirm complete tumor removal via microscopic margin assessment.
