Neoplasia Practice Questions

Q: Immunohistochemistry of a sample shows HMB-45. What malignancy does this marker indicate?

Melanoma. **Explanation:** **Correct Answer: B. Melanoma** HMB-45 (Human Melanoma Black-45) is a highly specific monoclonal antibody that reacts with **gp100**, a glycophosphoprotein found in the **pre-melanosomes** of melanocytes [1]. In pathology, it is a gold-standard immunohistochemical (IHC) marker used to confirm the diagnosis of malignant melanoma. While its sensitivity can be lower than S100 (which is very sensitive but less specific), HMB-45 is excellent for distinguishing melanoma from other poorly differentiated tumors [1]. **Why other options are incorrect:** * **A. Sarcoma:** These are tumors of mesenchymal origin. The characteristic IHC marker for most sarcomas is **Vimentin**. Specific sarcomas have their own markers (e.g., Desmin for rhabdomyosarcoma). * **C. Carcinoma:** These are tumors of epithelial origin. The primary IHC marker for carcinomas is **Cytokeratin (CK)**. * **D. None of the above:** Incorrect, as HMB-45 is a well-established marker for melanocytic lineage. **High-Yield Clinical Pearls for NEET-PG:** * **S100:** The most sensitive marker for melanoma (also positive in Schwann cells and Langerhans cells). * **Melan-A (MART-1):** Another highly specific and sensitive marker for melanocytic differentiation. * **SOX10:** A nuclear marker increasingly used for its high sensitivity in both primary and metastatic melanoma. * **HMB-45 Exception:** It is also positive in **Angiomyolipoma (AML)**, a benign tumor often associated with Tuberous Sclerosis, as AML contains "perivascular epithelioid cells" (PEComas) that express melanocytic markers. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1151-1152.

Q: Which histological feature characterizes an adenomatoid odontogenic tumour?

Tubular or duct-like cells. **Adenomatoid Odontogenic Tumour (AOT)**, often referred to as the "Two-Thirds Tumor," is a benign odontogenic neoplasm. The hallmark histological feature of AOT is the presence of **tubular or duct-like structures** (Option B). These structures are formed by cuboidal or columnar epithelial cells arranged in a circular pattern, with nuclei polarized away from the central lumen. This lumen often contains eosinophilic material or pre-dentin. It is important to note that these are not true glandular ducts but rather a specific pattern of odontogenic epithelium. **Analysis of Incorrect Options:** * **Option A (Polyhedral epithelial cells):** These are characteristic of **Pindborg Tumors** (Calcifying Epithelial Odontogenic Tumor), which feature sheets of polyhedral cells with distinct intercellular bridges and amyloid-like deposits. * **Option C (Stellate shaped cells):** Stellate reticulum-like cells are the classic feature of **Ameloblastoma**. While AOT can have spindle cells, the "star-shaped" arrangement is specific to the central portion of Ameloblastoma follicles. * **Option D (Stratified squamous epithelial cells):** These are found in **Squamous Odontogenic Tumors** or odontogenic cysts (like Keratocystic Odontogenic Tumors), but are not a defining feature of AOT. **NEET-PG High-Yield Pearls:** * **The "Two-Thirds" Rule:** 2/3rd occur in the **maxilla**, 2/3rd in **young females** (teens), and 2/3rd are associated with an **impacted canine** [1]. * **Radiology:** Appears as a well-defined radiolucency surrounding an unerupted tooth (follicular type), often containing "snowflake" calcifications. * **Treatment:** Conservative enucleation; recurrence is extremely rare. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Head and Neck, p. 741.

Q: What is true about multiple papillomatosis?

It is a premalignant condition.. **Explanation:** **Multiple Papillomatosis** (specifically Juvenile Laryngeal Papillomatosis) refers to the development of multiple benign squamous papillomas in the respiratory tract [1]. **1. Why Option C is Correct:** While individual papillomas are benign, multiple papillomatosis is considered a **premalignant condition**. Although the risk of spontaneous malignant transformation into squamous cell carcinoma is low (approx. 1–3%), it is a well-documented complication, especially in cases with long-standing disease or those exposed to co-carcinogens [1]. **2. Why the other options are incorrect:** * **Option A:** The causative agent is the **Human Papillomavirus (HPV)**, specifically genotypes **6 and 11**, not Herpes Simplex Virus. * **Option B:** **Radiotherapy is contraindicated.** It is not the treatment of choice because it significantly increases the risk of malignant transformation into an aggressive squamous cell carcinoma. The standard treatment is surgical debulking (CO2 laser or microdebrider). * **Option D:** Multiple papillomatosis is most common in **children (under age 5)** [1], often acquired during childbirth via an infected birth canal. A second peak occurs in adulthood (20–40 years), but the "multiple" juvenile form is classically a pediatric diagnosis. **High-Yield Clinical Pearls for NEET-PG:** * **Triad of symptoms:** Hoarseness of voice, chronic cough, and stridor. * **Histology:** Finger-like projections of non-keratinized stratified squamous epithelium with a central fibrovascular core and characteristic **koilocytic changes** [1]. * **Adjuvant therapy:** Cidofovir (antiviral) or Interferon-alpha may be used in refractory cases. * **Prevention:** The HPV vaccine (Gardasil) is effective in reducing the incidence of maternal transmission. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Head and Neck, pp. 745-746.

Q: A patient presents with bilateral proptosis. Biopsy from the orbital region shows spindle cells arranged in compact fascicles with nuclear palisading forming Verocay bodies (Antoni A pattern), alternating with loose hypocellular myxoid areas (Antoni B pattern). Immunohistochemistry shows strong S-100 positivity. What is the most likely diagnosis?

Schwannoma. ***Schwannoma*** - Bilateral proptosis with **Antoni A and B patterns** and **Verocay bodies** on biopsy are pathognomonic for schwannoma, particularly in the orbital region. - **S-100 positive** staining confirms neural origin, and orbital schwannomas commonly present with gradual **proptosis** and visual disturbances. *Leiomyoma* - Shows **smooth muscle differentiation** with spindle cells arranged in fascicles, positive for **smooth muscle actin (SMA)**. - Lacks the characteristic **Antoni patterns** and **Verocay bodies** seen in neural tumors like schwannoma. *Rhabdomyosarcoma* - Most common **primary orbital malignancy** in children, showing **cross-striations** and positive **desmin** staining. - Presents with **rapid onset proptosis** and is highly aggressive, unlike the benign nature suggested by typical schwannoma biopsy findings. *Fibromatosis* - Characterized by **proliferating fibroblasts** in a collagenous stroma without the **biphasic Antoni A/B pattern**. - Shows **beta-catenin positivity** and lacks **S-100 expression** and **Verocay bodies** diagnostic of schwannoma.

Q: All of the following are markers of melanoma except?

Cytokeratin-20. **Explanation:** The diagnosis of malignant melanoma relies heavily on Immunohistochemistry (IHC) because it can mimic various carcinomas and sarcomas histologically. **Why Cytokeratin-20 (CK20) is the correct answer:** Melanoma is a tumor of neuroectodermal origin (melanocytes), not epithelial origin. **Cytokeratins** are intermediate filaments found in epithelial cells; therefore, melanoma is characteristically **Cytokeratin negative**. CK20, specifically, is a marker for gastrointestinal carcinomas, transitional cell carcinomas, and Merkel cell carcinoma. Its absence helps rule out epithelial malignancies. **Analysis of Incorrect Options:** * **S-100:** This is the **most sensitive** marker for melanoma. While it lacks specificity (also positive in nerve sheath tumors, Langerhans cells, and cartilage), a negative S-100 almost always rules out melanoma. [1] * **HMB-45:** This is a highly **specific** marker for melanoma. It reacts against gp100, a protein found in stage II melanosomes. It is excellent for confirming the diagnosis but may be negative in desmoplastic variants. * **Vimentin:** As melanocytes are derived from the neural crest, they express vimentin (an intermediate filament of mesenchymal cells). Almost all melanomas are Vimentin positive. **High-Yield Clinical Pearls for NEET-PG:** * **Melan-A (MART-1):** Another highly specific and sensitive marker frequently used alongside HMB-45. * **SOX10:** A nuclear marker that is gaining popularity for its high sensitivity in both conventional and desmoplastic melanomas. * **The "Melanoma IHC Panel":** Typically includes S-100, HMB-45, and Melan-A. * **Rule of Thumb:** Melanoma is **S-100 (+), Vimentin (+), but Cytokeratin (-).** [1] **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1150-1153.

Question 1

Immunohistochemistry of a sample shows HMB-45. What malignancy does this marker indicate?

Accepted Answer

Melanoma

Answer

Sarcoma

Answer

Carcinoma

Answer

None of the above

Question 2

Erythropoietin is increased in all of the following conditions except:

Accepted Answer

Pancreatic carcinoma

Answer

Hepatocellular carcinoma

Answer

Renal cell carcinoma

Answer

Cerebellar hemangioblastoma

Question 3

In which of the following types of carcinoma of the breast is a comedo growth pattern seen?

Accepted Answer

Ductal carcinoma in situ

Answer

Medullary carcinoma

Answer

Lobular carcinoma in situ

Answer

Infiltrating lobular carcinoma

Question 4

Which histological feature characterizes an adenomatoid odontogenic tumour?

Accepted Answer

Tubular or duct-like cells

Answer

Polyhedral epithelial cells

Answer

Stellate shaped cells

Answer

Stratified squamous epithelial cells

Question 5

What is true about multiple papillomatosis?

Accepted Answer

It is a premalignant condition.

Answer

Herpes Simplex Virus is the causative agent.

Answer

Radiotherapy is the treatment of choice.

Answer

It is more common in individuals aged 15 to 33 years.

Question 6

What is the most common virus implicated in lymphoproliferative cancer in a child post-kidney transplant?

Accepted Answer

Epstein-Barr virus (EBV)

Answer

Cytomegalovirus (CMV)

Answer

Varicella-zoster virus

Answer

Human papillomavirus (HPV)

Question 7

A patient presents with bilateral proptosis. Biopsy from the orbital region shows spindle cells arranged in compact fascicles with nuclear palisading forming Verocay bodies (Antoni A pattern), alternating with loose hypocellular myxoid areas (Antoni B pattern). Immunohistochemistry shows strong S-100 positivity. What is the most likely diagnosis?

Accepted Answer

Schwannoma

Answer

Leiomyoma

Answer

Rhabdomyosarcoma

Answer

Fibromatosis

Question 8

Which of the following is NOT a common childhood tumor?

Accepted Answer

Pleomorphic rhabdomyosarcoma

Answer

Wilm's tumor

Answer

Neuroblastoma

Answer

Embryonal rhabdomyoma

Question 9

Carcinoembryonic antigen (CEA) is elevated in all conditions except which one?

Accepted Answer

Emphysema

Answer

Alcoholic Cirrhosis

Answer

Carcinoma of the Colon

Answer

Ulcerative Colitis

Question 10

All of the following are markers of melanoma except?

Accepted Answer

Cytokeratin-20

Answer

S-100

Answer

HMB-45

Answer

Vimentin

Neoplasia — MCQs

Neoplasia — MCQs

On this page

Practice by Chapter

Want unlimited practice?