Neoplasia Practice Questions

Q: BRAF acts as a main proto-oncogene in which of the following conditions?

All of the above. **Explanation:** The **BRAF gene** encodes a protein belonging to the RAF family of serine/threonine kinases. It is a vital component of the **MAPK/ERK signaling pathway**, which regulates cell growth, proliferation, and survival. Mutations in BRAF, most commonly the **V600E mutation** (substitution of valine by glutamic acid at codon 600) [2], lead to constitutive activation of this pathway, driving oncogenesis [1]. **Why "All of the Above" is correct:** * **Hairy Cell Leukemia (HCL):** The BRAF V600E mutation is considered a "defining" genetic event in HCL, present in nearly **100% of cases** [2]. It serves as a critical diagnostic marker to differentiate HCL from other B-cell lymphoproliferative disorders. * **Melanoma:** BRAF mutations are found in approximately **40-60% of cutaneous melanomas** [1]. This discovery led to the development of targeted therapies like Vemurafenib and Dabrafenib. * **Langerhans Cell Histiocytosis (LCH):** BRAF V600E mutations are identified in about **50-60% of LCH cases** [2], establishing it as a neoplastic process rather than a reactive one. **Clinical Pearls for NEET-PG:** 1. **Papillary Thyroid Carcinoma:** BRAF V600E is the most common mutation (approx. 45%) and is often associated with a poorer prognosis. 2. **Colon Cancer:** BRAF mutations are seen in about 10% of cases, typically associated with the **microsatellite instability (MSI)** pathway and serrated polyps. 3. **Targeted Therapy:** The presence of BRAF mutations allows for the use of **BRAF inhibitors** (e.g., Vemurafenib), which have revolutionized the treatment of metastatic melanoma and refractory HCL [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1150-1151. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus, pp. 629-630.

Question 1

BRAF acts as a main proto-oncogene in which of the following conditions?

Accepted Answer

All of the above

Answer

Hairy cell leukemia

Answer

Langerhans cell histiocytosis

Answer

Melanoma

Question 2

Which of the following conditions is associated with an increase in alpha-fetoprotein?

Accepted Answer

Hepatoblastoma

Answer

Neuroblastoma

Answer

Thymoma

Answer

Angiosarcoma

Question 3

All of the following are invasive carcinoma of the breast except?

Accepted Answer

Medullary carcinoma

Answer

Comedo carcinoma

Answer

Colloid carcinoma

Answer

Lobular carcinoma in situ

Question 4

A 41-year-old man presented with a 9-month history of cough, exertional dyspnea, nocturnal diaphoresis, and 10 kg weight loss. Physical examination revealed painless, massive, discrete, rubbery cervical, supraclavicular, and axillary lymphadenopathy. Chest radiography showed bilateral hilar lymphadenopathy. Serum calcium level was elevated at 16.2 mg/dL, with parathyroid hormone within the normal range. What is the most appropriate diagnostic investigation?

Accepted Answer

Excisional biopsy of the axillary node

Answer

Fine-needle aspiration cytology (FNAC) of the mediastinal lymph node

Answer

CT scan of the chest and abdomen

Answer

Core needle biopsy of the neck node

Question 5

Which congenital syndrome is associated with lymphoproliferative malignancy?

Accepted Answer

Chediak Higashi syndrome

Answer

Bloom syndrome

Answer

Fanconi's anemia

Answer

Turner syndrome

Question 6

Which malignancies most commonly metastasize to the jaws?

Accepted Answer

All of the above

Answer

Lung

Answer

Prostate

Answer

Colorectal

Question 7

Carcinomas of all of the following sites metastasize to the vertebral column except?

Accepted Answer

Esophagus

Answer

Breast

Answer

Bronchus

Answer

Prostate

Question 8

Which gene is associated with familial adenomatous polyposis?

Accepted Answer

APC

Answer

p53

Answer

Rb

Answer

RET

Question 9

In the TNM staging system, what does the 'N' represent?

Accepted Answer

Number of involved lymph nodes

Answer

Nature of tumor

Answer

Number of tumors

Answer

Metastasis

Question 10

BRCA 1 gene is located on which chromosome arm?

Accepted Answer

17q

Answer

11q

Answer

13q

Answer

19q

Neoplasia — MCQs

Neoplasia — MCQs

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