Neoplasia Practice Questions

Q: Which of the following is HMB45 negative?

Juxtaglomerular tumor. **Explanation:** The question tests your knowledge of **HMB-45 (Human Melanoma Black-45)**, a monoclonal antibody that reacts against **gp100**, a glycoprotein found in premelanosomes. While primarily a marker for melanocytic tumors, it is also expressed in a specific family of tumors known as **PEComas** (Perivascular Epithelioid Cell tumors). **Why Juxtaglomerular Tumor is the Correct Answer:** A **Juxtaglomerular tumor (Reninoma)** is a rare benign tumor of the kidney arising from the juxtaglomerular cells. These cells are modified smooth muscle cells of the afferent arteriole. On immunohistochemistry (IHC), they are positive for **Renin, Vimentin, and CD117**, but they are **HMB-45 negative**. **Analysis of Incorrect Options:** * **Melanoma:** HMB-45 is highly specific for melanocytic differentiation. It is positive in the vast majority of malignant melanomas (except desmoplastic variants). * **Angiomyolipoma (AML):** This is the most common member of the **PEComa family**. Despite being a mesenchymal tumor (composed of blood vessels, smooth muscle, and fat), the "epithelioid" smooth muscle cells characteristically express melanocytic markers like **HMB-45 and Melan-A** [1]. * **Tendon Clear Cell Sarcoma:** Often referred to as "Melanoma of Soft Parts," this tumor harbor the **t(12;22)** translocation. It consistently expresses **HMB-45 and S100**, mimicking the IHC profile of melanoma. **High-Yield Clinical Pearls for NEET-PG:** * **PEComa Family:** Includes Angiomyolipoma (kidney), Lymphangiomyomatosis (lung), and Clear cell "sugar" tumor (lung). All are typically **HMB-45 positive** [1]. * **HMB-45 vs. S100:** HMB-45 is more specific for melanoma but less sensitive than S100. * **Juxtaglomerular Tumor Triad:** Hypertension, Hypokalemia, and High plasma renin activity. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 957-958.

Q: Comment on the histopathological specimen?

Teratoma. ***Teratoma*** - Contains tissue elements from **all three germ layers** (ectoderm, mesoderm, endoderm) including neural tissue, cartilage, muscle, and epithelial structures. - Histologically shows **mature differentiated tissues** with organized architecture, distinguishing it from other tumors with uniform cell populations. *Rhabdomyoma* - Shows **mature striated muscle fibers** with cross-striations and multiple nuclei, but lacks the multi-tissue diversity seen in teratoma. - Appears as a **benign, well-differentiated** tumor composed exclusively of skeletal muscle tissue. *Rhabdomyosarcoma* - Exhibits **malignant mesenchymal cells** with high mitotic activity and cellular atypia, unlike the organized mature tissues in teratoma. - Shows **primitive round cells** or spindle cells with **rhabdomyoblasts** containing eosinophilic cytoplasm, lacking multi-lineage differentiation. *Neuroblastoma* - Characterized by **small round blue cells** arranged in **Homer-Wright rosettes** with minimal cytoplasm and hyperchromatic nuclei. - Shows **primitive neural tissue** only, without the diverse tissue types from multiple germ layers seen in teratoma.

Question 1

Which of the following is HMB45 negative?

Accepted Answer

Juxtaglomerular tumor

Answer

Melanoma

Answer

Angiomyolipoma

Answer

Tendon clear cell sarcoma

Question 2

All of the following are tumor suppressor genes except?

Accepted Answer

SMAD1

Answer

NF1

Answer

pRb

Answer

p53

Question 3

Which chromosome is associated with retinoblastoma?

Accepted Answer

13

Answer

11

Answer

17

Answer

15

Question 4

Familial tendency is not seen in which of the following malignancies?

Accepted Answer

Laryngeal carcinoma

Answer

Sarcomas

Answer

Stomach carcinoma

Answer

Colon carcinoma

Question 5

What is the most common sarcoma in a person receiving immunosuppressive treatment?

Accepted Answer

Kaposi's sarcoma

Answer

Lymphoma sarcoma

Answer

Osteosarcoma

Answer

Angiosarcoma

Question 6

Which of the following statements about chromothrypsis is NOT true?

Accepted Answer

It is associated with inactivation of tumor suppressor genes and activation of oncogenes.

Answer

It is associated with chromosome rearrangements termed as chromosome shattering.

Answer

It is observed in 1% to 2% of cancers as a whole.

Answer

It has an increased frequency in 25% of osteosarcomas and a high frequency in gliomas.

Question 7

A woman who is heterozygous for glucose-6-phosphate dehydrogenase (G6PD), a polymorphic enzyme transcribed from the X chromosome, develops chronic myeloid leukemia. Restriction fragment length polymorphism (RFLP) studies on the tumor cells for G6PD reveal that only a single form of the enzyme is transcribed. This finding supports which of the following features of neoplasia?

Accepted Answer

Monoclonality

Answer

Genetic mutation

Answer

Mosaicism

Answer

Oncogene activation

Question 8

Comment on the histopathological specimen?

Accepted Answer

Teratoma

Answer

Rhabdomyoma

Answer

Rhabdomyosarcoma

Answer

Neuroblastoma

Question 9

Malignancy is typically associated with disordered differentiation and mutation. Which of the following options best describes anaplasia?

Accepted Answer

Muscle tumor cells forming giant cells

Answer

Hepatic tumor cells synthesizing bile

Answer

Skin tumor cells producing keratin pearls

Answer

Bronchial epithelial cells producing keratin pearls

Question 10

Which of the following statements about p53 is TRUE, except?

Accepted Answer

Its activity in cells decreases following UV radiation and stimulates the cell cycle.

Answer

It regulates certain genes involved in the cell cycle.

Answer

Its increased levels can induce apoptosis.

Answer

Mutations in p53 are the most common genetic alterations seen in human cancer.

Neoplasia — MCQs

Neoplasia — MCQs

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