Neoplasia Practice Questions

Q: Squamous cell carcinoma arises from which cell type?

Excretory duct reserve cell.. ### Explanation The histogenesis of salivary gland tumors is best explained by the **Bicellular Theory**, which suggests that all salivary neoplasms arise from two types of "reserve" (stem) cells: the intercalated duct reserve cell and the excretory duct reserve cell. **1. Why Option B is Correct:** The **Excretory duct reserve cells** are located in the large, distal ducts of the salivary glands. These cells are multipotent and are the precursors for the stratified squamous and columnar epithelium of the excretory ducts. Consequently, malignancies characterized by squamous differentiation—specifically **Squamous Cell Carcinoma (SCC)** and **Mucoepidermoid Carcinoma**—originate from these cells. **2. Why the Other Options are Incorrect:** * **Option A:** **Intercalated duct reserve cells** are located in the proximal portion of the ductal system. These cells give rise to the acini, intercalated ducts, and myoepithelial cells. Tumors arising from this lineage include **Pleomorphic Adenoma, Adenoid Cystic Carcinoma, and Acinic Cell Carcinoma.** * **Option C:** While both cells contribute to the spectrum of salivary tumors, they have distinct "zones of origin." SCC is restricted to the excretory duct lineage. **Clinical Pearls for NEET-PG:** * **Most common benign salivary tumor:** Pleomorphic Adenoma (arises from intercalated duct/myoepithelial cells). * **Most common malignant salivary tumor:** Mucoepidermoid Carcinoma (arises from excretory duct cells). * **Primary SCC of the salivary gland** is rare and must be differentiated from metastatic SCC (usually from the skin or oropharynx) or the squamous component of a Mucoepidermoid Carcinoma. * **Warthin’s Tumor** is unique as it is thought to arise from heterotopic salivary gland tissue trapped within intra-parotid lymph nodes.

Q: What causes the appearance of mammary skin described as "peau d'orange"?

Lymphatic invasion. **Explanation:** **Peau d’orange** (French for "orange peel skin") is a classic clinical sign of inflammatory breast cancer or advanced underlying malignancy. [1] **Why Lymphatic Invasion is Correct:** The characteristic appearance is caused by the **invasion of dermal lymphatics** by tumor emboli. This leads to lymphatic obstruction and localized **lymphedema**. [1] As the skin swells, the hair follicles remain tethered to the underlying dermis by suspensory ligaments (ligaments of Cooper). This creates a pitted, dimpled appearance where the follicles are depressed relative to the edematous surrounding skin, mimicking the texture of an orange peel. **Analysis of Incorrect Options:** * **A & B (Intraepithelial/Subepidermal carcinoma):** These terms refer to the location of the cancer cells within the skin layers. While cancer cells are present in the dermis in peau d'orange, the *mechanism* of the skin change is mechanical fluid backup (edema), not the mere presence of cells in the epithelium. * **D (Vascular embolization):** While tumor cells can enter blood vessels (hematogenous spread), this typically leads to distant metastasis (e.g., to bone or lungs) rather than localized cutaneous edema and dimpling. **NEET-PG High-Yield Pearls:** * **Clinical Significance:** Peau d’orange is a hallmark of **Inflammatory Breast Cancer**, which is clinically staged as **T4d** (locally advanced). * **Differential Diagnosis:** It can also be seen in severe mastitis, though the presence of a mass or lack of response to antibiotics points toward malignancy. * **Pathology Link:** Always associate "dermal lymphatic obstruction" [1] with "peau d'orange" and "Cooper’s ligaments" with the "pitting/dimpling" effect. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Liver And Biliary System Disease, pp. 453-454.

Question 1

Squamous cell carcinoma arises from which cell type?

Accepted Answer

Excretory duct reserve cell.

Answer

Intercalated duct reserve cell.

Answer

Both intercalated and excretory duct reserve cells.

Answer

None of the above.

Question 2

What causes the appearance of mammary skin described as "peau d'orange"?

Accepted Answer

Lymphatic invasion

Answer

Intraepithelial carcinoma

Answer

Subepidermal carcinoma

Answer

Vascular embolization

Question 3

In which one of the following does the host factor show a bimodal incidence curve?

Accepted Answer

Hodgkin's lymphoma

Answer

Kaposi's sarcoma

Answer

Osteosarcoma

Answer

Lung cancer

Question 4

The Azzopardi effect is seen in which of the following conditions?

Accepted Answer

Small cell carcinoma

Answer

Squamous cell carcinoma

Answer

Large cell carcinoma

Answer

Adenocarcinoma lung

Question 5

A child is born with a single functional copy of a tumor suppressor gene. At the age of 5 years, the remaining normal allele is lost through mutation. As a result, the ability to control the transition from G1 to the S phase of the cell cycle is lost. Which of the following neoplasms is most likely to arise by means of this mechanism?

Accepted Answer

Retinoblastoma

Answer

Breast carcinoma

Answer

Adenocarcinoma of colon

Answer

Cerebral astrocytoma

Question 6

Which of the following mutations is NOT involved in tobacco-induced squamous cell carcinoma?

Accepted Answer

P16

Answer

P53

Answer

P63

Answer

NOTCH 1

Question 7

Which of the following is a marker for carcinoma of the colon?

Accepted Answer

CEA

Answer

AFP

Answer

CA-125

Answer

HCG

Question 8

What is the most definite feature of a malignant tumour?

Accepted Answer

Metastasis

Answer

Haemorrhage

Answer

Increased mitoses

Answer

Necrosis

Question 9

A 51-year-old male with a 20-year history of tobacco chewing presents with a slowly enlarging, white, irregular mass on the floor of his mouth, measuring 1.3 cm. Biopsies of this lesion are most likely to reveal which malignancy?

Accepted Answer

Squamous cell carcinoma

Answer

Acinic cell carcinoma

Answer

Adenocarcinoma

Answer

Basal cell carcinoma

Question 10

A metastatic carcinoma in the brain of an adult most often originates from a primary tumor in which of the following locations?

Accepted Answer

Lung

Answer

Stomach

Answer

Ovary

Answer

Oral cavity

Neoplasia — MCQs

Neoplasia — MCQs

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