Neoplasia Practice Questions

Q: The most common malignancy of the oral cavity is:

Squamous cell carcinoma. **Explanation:** **Squamous Cell Carcinoma (SCC)** is the most common malignancy of the oral cavity, accounting for approximately **90-95%** of all oral cancers. The oral cavity is lined by stratified squamous epithelium; chronic exposure to carcinogens—most notably **tobacco** (smoking and smokeless) and **alcohol**—leads to a progression from dysplasia to invasive carcinoma [1]. In recent years, **Human Papillomavirus (HPV-16)** has also been identified as a significant risk factor, particularly for oropharyngeal sites [1]. **Analysis of Incorrect Options:** * **Basal Cell Carcinoma (BCC):** While BCC is the most common skin cancer, it rarely affects the oral mucosa. It typically occurs on sun-exposed skin, such as the upper face. * **Transitional Cell Carcinoma:** This malignancy arises from the urothelium and is characteristic of the urinary tract (bladder, ureters). It is not found in the oral cavity. * **Melanoma:** Oral mucosal melanoma is extremely rare (less than 1% of oral malignancies). Although highly aggressive, it is far less common than SCC. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** The lateral border of the tongue and the floor of the mouth are the most frequent locations for oral SCC [1]. * **Precursor lesions:** Leukoplakia (white patch) and Erythroplakia (red patch) are significant premalignant conditions; Erythroplakia carries a much higher risk of malignant transformation [1]. * **Field Cancerization:** This concept explains why patients with one oral SCC are at high risk for developing secondary primary tumors due to diffuse carcinogen exposure across the mucosal surface. * **Lymphatic Spread:** Oral SCC typically metastasizes first to the submental and deep cervical lymph nodes. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Lung, pp. 738-741.

Q: A patient was incidentally diagnosed with a lump during a routine health checkup. Following ultrasound and guided biopsy, histopathological examination revealed a diagnosis. The patient was initiated on chemotherapy that included a drug obtained from a specific plant. What is the site of action of this drug?

Tubulin (mitotic inhibitor). ***Tubulin (mitotic inhibitor)*** - Plant-derived chemotherapeutic agents like **vinca alkaloids** (vincristine, vinblastine from *Vinca rosea*) and **taxanes** (paclitaxel from *Taxus brevifolia*) target **tubulin** and disrupt **microtubule** formation. - These drugs prevent proper **mitotic spindle** formation, leading to cell cycle arrest in **M-phase** and subsequent **apoptosis** in rapidly dividing cancer cells. *DNA alkylation* - **Alkylating agents** like **cyclophosphamide** and **nitrogen mustards** form **covalent bonds** with DNA bases, causing cross-linking. - These are not typically plant-derived drugs and work through direct **DNA damage** rather than affecting cellular structures. *Topoisomerase II inhibition* - **Etoposide** and **doxorubicin** inhibit **topoisomerase II**, preventing DNA **supercoiling** and causing DNA breaks. - While some topoisomerase inhibitors are plant-derived, the question specifically hints at drugs affecting **cellular division machinery** rather than DNA enzymes. *DNA intercalation* - **Intercalating agents** like **actinomycin D** insert between **DNA base pairs**, distorting the double helix structure. - These drugs primarily affect **transcription** and **replication** processes rather than the **mitotic apparatus** targeted by plant-derived anti-mitotic agents.

Q: RET gene mutation is associated with which malignancy?

Medullary carcinoma of the thyroid. **Explanation:** The **RET (REarranged during Transformation)** gene is a proto-oncogene located on chromosome 10 that encodes a receptor tyrosine kinase. Mutations in this gene lead to constitutive activation of signaling pathways, promoting uncontrolled cell growth [1]. 1. **Why Medullary Carcinoma of the Thyroid (MTC) is correct:** RET mutations are the hallmark of MTC. Approximately 95-100% of hereditary MTC (associated with **MEN 2A and 2B**) and about 50% of sporadic MTC cases harbor RET mutations [1]. In MEN 2 syndromes, germline mutations lead to C-cell hyperplasia, the precursor to MTC [2]. 2. **Why other options are incorrect:** * **Pheochromocytoma:** While pheochromocytoma *is* associated with RET mutations (as part of MEN 2A/2B), it is not the primary diagnostic association compared to MTC [1]. MTC is the most consistent feature of MEN 2. * **Lymphoma:** Associated with mutations/translocations like *c-MYC* (Burkitt), *BCL-2* (Follicular), or *BCL-6*. * **Renal Cell Carcinoma:** Primarily associated with *VHL* gene mutations (Clear cell RCC) or *MET* proto-oncogene (Papillary RCC). **High-Yield Clinical Pearls for NEET-PG:** * **MEN 2A (Sipple Syndrome):** MTC + Pheochromocytoma + Parathyroid Hyperplasia [1]. * **MEN 2B (Williams-Pollock Syndrome):** MTC + Pheochromocytoma + Mucosal Neuromas + Marfanoid habitus [2]. * **Prophylactic Thyroidectomy:** Recommended for children carrying germline RET mutations because MTC penetrance is nearly 100%. * **Papillary Thyroid Carcinoma:** Associated with **RET/PTC rearrangements** (different from the point mutations seen in MTC) [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1097-1098. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Endocrine System, pp. 1102-1103.

Question 1

Which of the following is a triple negative breast cancer?

Accepted Answer

Secretory cell cancer

Answer

Colloid Cancer

Answer

Acinic Cell Carcinoma

Answer

Mucinous Carcinoma

Question 2

The most common malignancy of the oral cavity is:

Accepted Answer

Squamous cell carcinoma

Answer

Basal cell carcinoma

Answer

Transitional cell carcinoma

Answer

Melanoma

Question 3

Which of the following is not a tumor marker?

Accepted Answer

Human leucocyte antigen A2

Answer

CEA

Answer

Tyrosinase

Answer

AFP

Question 4

Epstein-Barr virus (EBV) is associated with which type of cancer?

Accepted Answer

Nasopharyngeal carcinoma

Answer

Epidermodysplasia

Answer

Kaposi sarcoma

Answer

None of the above

Question 5

A patient was incidentally diagnosed with a lump during a routine health checkup. Following ultrasound and guided biopsy, histopathological examination revealed a diagnosis. The patient was initiated on chemotherapy that included a drug obtained from a specific plant. What is the site of action of this drug?

Accepted Answer

Tubulin (mitotic inhibitor)

Answer

DNA alkylation

Answer

Topoisomerase II inhibition

Answer

DNA intercalation

Question 6

What type of fibroadenosis is most likely to undergo malignant change?

Accepted Answer

Epitheliosis

Answer

Adenosis

Answer

Sclerosing adenosis

Answer

Cystic

Question 7

Which of the following is not a benign tumor?

Accepted Answer

Hepatoma

Answer

Lipoma

Answer

Leiomyoma

Answer

Chondroma

Question 8

Paget's disease of the nipple is stained positive for:

Accepted Answer

CEA

Answer

S 100

Answer

Both of the above

Answer

None of the above

Question 9

Gleason's staging is used in which of the following malignancies?

Accepted Answer

Carcinoma of the prostate

Answer

Carcinoma of the bladder

Answer

Carcinoma of the pancreas

Answer

Carcinoma of the colon

Question 10

RET gene mutation is associated with which malignancy?

Accepted Answer

Medullary carcinoma of the thyroid

Answer

Pheochromocytoma

Answer

Lymphoma

Answer

Renal cell carcinoma

Neoplasia — MCQs

Neoplasia — MCQs

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