Skin Tumors Practice Questions

Q: What is the dermatological sign associated with carcinoma of the stomach?

Acanthosis Nigrans. **Explanation:** **Acanthosis Nigricans (AN)** is the correct answer. While AN is most commonly associated with insulin resistance and obesity (Benign AN), its sudden, severe, and widespread onset in an older individual—often involving the palms (tripe palms) and mucous membranes—is a classic **paraneoplastic syndrome**. **Malignant Acanthosis Nigricans** is most frequently associated with **adenocarcinomas of the gastrointestinal tract**, with **stomach cancer** being the most common (approx. 50-60% of cases). It is thought to be mediated by tumor-secreted growth factors like Transforming Growth Factor-alpha (TGF-α) acting on epidermal EGF receptors. **Analysis of Incorrect Options:** * **A. Palmoplantar Keratoderma (PPK):** While acquired PPK can be paraneoplastic (Howel-Evans Syndrome), it is specifically linked to **Esophageal carcinoma**, not primarily the stomach. * **B. Acquired Ichthyosis:** This sudden onset of "fish-like" scaling in adulthood is most strongly associated with **lymphomas** (specifically Hodgkin’s Lymphoma), rather than gastric malignancies. * **D. Acrokeratosis Paraneoplastica (Bazex Syndrome):** This presents with psoriasiform plaques on acral sites (ears, nose, fingers). It is highly specific for squamous cell carcinomas of the **upper aerodigestive tract** (head, neck, and esophagus). **High-Yield Clinical Pearls for NEET-PG:** * **Tripe Palms:** When AN affects the palms, appearing velvety and rugose, it is 90% predictive of internal malignancy. If seen with AN, think **Stomach CA**; if seen alone, think **Lung CA**. * **Leser-Trélat Sign:** The sudden eruption of multiple Seborrheic Keratoses is another major cutaneous marker for **Gastric Adenocarcinoma**. * **Sister Mary Joseph Nodule:** A palpable nodule at the umbilicus representing metastasis from a pelvic or abdominal malignancy (most commonly Stomach CA).

Q: Which of the following conditions shows susceptibility to squamous cell carcinoma in the skin?

All the above. **Explanation:** Squamous Cell Carcinoma (SCC) of the skin is a malignant tumor of epidermal keratinocytes. Its development is often preceded by precancerous lesions or genetic conditions that impair the skin's ability to repair DNA damage or control viral oncogenesis. * **Epidermodysplasia Verruciformis (EV):** This is a rare genetic disorder characterized by an abnormal susceptibility to **Human Papillomaviruses (HPV)**, particularly types 5 and 8. Patients develop chronic wart-like lesions that have a high propensity (30-60%) for transforming into SCC, especially on sun-exposed areas. * **Actinic Keratosis (AK):** Also known as solar keratosis, these are considered **premalignant** lesions. They represent the earliest clinical stage of SCC in situ. Histologically, they show keratinocyte atypia; if left untreated, approximately 1-10% progress to invasive SCC. * **Xeroderma Pigmentosum (XP):** This is an autosomal recessive disorder caused by a defect in **Nucleotide Excision Repair (NER)**. Patients cannot repair DNA damage caused by UV radiation, leading to a 10,000-fold increased risk of developing skin cancers, including SCC, Basal Cell Carcinoma (BCC), and Melanoma at a very young age. Since all three conditions are well-documented precursors or risk factors for SCC, **Option D** is the correct answer. **High-Yield Clinical Pearls for NEET-PG:** * **Marjolin’s Ulcer:** SCC arising in chronic scars, non-healing ulcers, or burn sites. It is more aggressive than UV-induced SCC. * **Bowen’s Disease:** A clinical term for SCC in situ (full-thickness atypia without basement membrane invasion). * **Arsenic Exposure:** A systemic risk factor that typically leads to multiple SCCs on the palms and soles. * **Most common site for SCC:** Lower lip (whereas BCC is more common on the upper lip).

Q: Which of the following lesions shows characteristic anagen, catagen, and telogen phases?

Keratoacanthoma. **Explanation:** **Keratoacanthoma (KA)** is a common, rapidly growing epithelial tumor that clinically and histologically resembles Squamous Cell Carcinoma (SCC). The hallmark of KA is its unique life cycle, which mimics the **hair follicle cycle**. It originates from the follicular infundibulum and progresses through three distinct stages: 1. **Proliferative phase (Anagen-like):** Rapid growth over 4–6 weeks, forming a dome-shaped nodule with a central keratinous plug. 2. **Stationary phase (Catagen-like):** Growth ceases, and the lesion stabilizes. 3. **Involutional phase (Telogen-like):** Spontaneous regression occurs over weeks to months, often leaving a puckered scar. **Analysis of Incorrect Options:** * **Basal Cell Carcinoma (BCC):** The most common skin cancer. It is characterized by slow growth, "pearly" borders, and telangiectasia. It does not undergo spontaneous regression or follow a follicular cycle. * **Leukoplakia:** A clinical term for a white patch on the mucosa that cannot be characterized as any other disease. It is a premalignant condition, not a follicular-derived tumor. * **Squamous Cell Carcinoma (SCC):** While KA is often considered a well-differentiated variant of SCC, true SCC is characterized by progressive, uncontrolled growth and invasion without a programmed involutional phase. **High-Yield NEET-PG Pearls:** * **Clinical Appearance:** "Volcano-like" appearance (dome-shaped with a central keratin plug). * **Histology:** Shows a central keratin-filled crater with "lips" or "buttresses" of overhanging epithelium. * **Syndrome Association:** Multiple keratoacanthomas are seen in **Muir-Torre Syndrome** (associated with internal malignancies) and **Grzybowski type** (generalized eruptive KAs). * **Management:** Despite spontaneous regression, surgical excision is usually recommended because it is difficult to distinguish KA from aggressive SCC.

Q: A patient presents with multiple, pearly papules on the face. Biopsy reveals a malignant tumor. Which of the following microscopic features would most likely be observed?

Palisading nuclei. **Explanation:** The clinical presentation of **pearly papules** on the face, often with telangiectasia, is the classic description of **Basal Cell Carcinoma (BCC)**, the most common skin cancer. **Why the correct answer is right:** The hallmark histopathological feature of BCC is the presence of nests or islands of basaloid cells (cells with large, dark nuclei and scant cytoplasm). At the periphery of these nests, the nuclei align themselves in a parallel, fence-like arrangement known as **peripheral palisading**. Additionally, a characteristic "retraction artifact" (clefting) is often seen between the tumor nests and the surrounding stroma. **Why the incorrect options are wrong:** * **A. Cytoplasmic viral inclusions:** These are characteristic of viral infections like Molluscum Contagiosum (Henderson-Patterson bodies) or HPV (koilocytes), not malignant tumors like BCC. * **B. Keratin:** While BCC can occasionally show focal keratinization (Basosquamous variant), **Keratin pearls** are the pathognomonic feature of **Squamous Cell Carcinoma (SCC)**. * **C. Melanin:** While "Pigmented BCC" exists, melanin is the defining feature of **Melanoma**. In a general question about pearly papules, palisading is the more specific diagnostic marker for BCC. **High-Yield NEET-PG Pearls:** * **Most common site:** Upper 2/3rd of the face (above the line joining the earlobe to the angle of the mouth). * **Risk Factor:** Chronic UV exposure; also associated with **Gorlin Syndrome** (PTCH gene mutation). * **Behavior:** Locally invasive ("Rodent ulcer") but rarely metastasizes. * **Treatment of choice:** Surgical excision or Mohs Micrographic Surgery (for high-risk areas).

Q: What is true regarding Kaposi's sarcoma?

All of the above are true. **Explanation:** Kaposi’s Sarcoma (KS) is a multicentric angioproliferative tumor derived from vascular and lymphatic endothelial cells. It is uniquely associated with **Human Herpesvirus 8 (HHV-8)**, also known as Kaposi Sarcoma-associated Herpesvirus (KSHV). * **Option A (CD4 Count):** While KS is an AIDS-defining illness typically seen when CD4 counts are <200 cells/mm³, it can occur in individuals with **normal CD4 counts**. This is particularly true in the "Classic (Sporadic)" variant seen in elderly Mediterranean men and the "Endemic (African)" variant, where HIV infection is not a prerequisite. * **Option B (Etiology):** HHV-8 is the definitive causative agent across all four clinical types (Classic, Endemic, Iatrogenic/Transplant-related, and AIDS-associated). The virus induces spindle cell proliferation and angiogenesis. * **Option C (Koebner’s Phenomenon):** KS is one of the few neoplastic conditions that can exhibit the **Pseudo-Koebner phenomenon**, where new lesions develop at sites of trauma or previous injury. **Clinical Pearls for NEET-PG:** * **Histopathology:** Characterized by **spindle-shaped cells**, slit-like vascular spaces containing extravasated RBCs, and **hyaline droplets**. * **Clinical Presentation:** Presents as palpable, non-blanching, violaceous (purplish) macules, plaques, or nodules. * **Promontory Sign:** A characteristic histological feature where small vessels appear to protrude into larger, ectatic vascular spaces. * **Treatment:** Highly Active Antiretroviral Therapy (HAART) is the mainstay for AIDS-related KS; localized lesions may be treated with radiotherapy or intralesional vinblastine.

Question 1

What is the dermatological sign associated with carcinoma of the stomach?

Accepted Answer

Acanthosis Nigrans

Answer

Palmoplantar keratoderma

Answer

Acquired ichthyosis

Answer

Acrokeratosis paraneopiastica

Question 2

Which of the following conditions shows susceptibility to squamous cell carcinoma in the skin?

Accepted Answer

All the above

Answer

Epidermodysplasia verruciformis

Answer

Actinic keratosis

Answer

Xeroderma pigmentosum

Question 3

Which of the following lesions shows characteristic anagen, catagen, and telogen phases?

Accepted Answer

Keratoacanthoma

Answer

Basal cell carcinoma

Answer

Leukoplakia

Answer

Squamous cell carcinoma

Question 4

A patient presents with multiple, pearly papules on the face. Biopsy reveals a malignant tumor. Which of the following microscopic features would most likely be observed?

Accepted Answer

Palisading nuclei

Answer

Cytoplasmic viral inclusions

Answer

Keratin

Answer

Melanin

Question 5

What is true regarding Kaposi's sarcoma?

Accepted Answer

All of the above are true

Answer

Can occur even when CD4 count is normal

Answer

Human Herpesvirus 8 (HHV-8) is the etiological agent

Answer

Koebner's phenomenon may be observed with it

Skin Tumors — MCQs

Skin Tumors — MCQs

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