Skin Tumors Practice Questions

Q: Basal cell carcinoma commonly spreads by?

Direct spread. **Explanation:** **Basal Cell Carcinoma (BCC)** is the most common skin cancer globally. It arises from the non-keratinizing cells of the basal layer of the epidermis. 1. **Why Direct Spread is Correct:** BCC is characterized by **slow, progressive local invasion**. It spreads by infiltrating surrounding tissues (skin, subcutaneous fat, muscle, and even bone) through "finger-like" projections. This destructive local behavior is why it is colloquially termed a **"Rodent Ulcer"**—it appears as if a rodent has gnawed through the tissue. 2. **Why Other Options are Incorrect:** * **Lymphatic and Haematogenous Spread:** These are extremely rare in BCC (occurring in <0.1% of cases). BCC lacks the inherent biological aggressiveness to easily penetrate vessel walls or survive in the circulation. If metastasis does occur, it usually involves very large, neglected tumors or specific aggressive subtypes, but it is never the "common" mode of spread. * **All the above:** Since distant metastasis is an exception rather than the rule, this option is incorrect. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Site:** Face, specifically above the line joining the lobe of the ear to the angle of the mouth (inner canthus and nose are frequent sites). * **Risk Factor:** Chronic UV light exposure is the primary trigger. * **Clinical Hallmark:** A pearly, translucent papule with telangiectasia and rolled-out borders. * **Histopathology:** Shows **Peripheral Palisading** (nuclei at the edge of tumor nests align vertically) and **Retraction Artifacts**. * **Prognosis:** Excellent, as it rarely metastasizes, though it can cause significant local morbidity if left untreated.

Q: A 19-year-old man has a pigmented skin lesion. Which of the following characteristics suggests a dysplastic nevus (atypical mole) rather than a benign acquired nevus?

Location on the buttock. **Explanation:** The diagnosis of a **Dysplastic Nevus (Atypical Mole)** is based on clinical and histological criteria that distinguish it from common acquired nevi. **1. Why "Location on the buttock" is correct:** Common acquired nevi typically appear on sun-exposed areas and are rarely found on "double-covered" sites like the buttocks or breasts. In contrast, dysplastic nevi frequently occur on both sun-exposed and **non-sun-exposed areas** (e.g., buttocks, scalp, female breasts). Finding a pigmented lesion in these protected areas is a strong clinical indicator of atypia and increases the suspicion of Dysplastic Nevus Syndrome. **2. Analysis of Incorrect Options:** * **A. Uniform tan color:** This is a feature of a **benign** nevus. Dysplastic nevi characteristically show **variegated coloring** (shades of brown, tan, pink, or black) and irregular, ill-defined borders. * **C. 4 mm in diameter:** Common nevi are usually small ( 50 to 100** lesions). **Clinical Pearls for NEET-PG:** * **ABCDE Criteria:** Used for screening (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving). * **Friedman-Rigel Criteria:** Clinical hallmarks of dysplastic nevi include a "fried-egg" appearance (central papule with a flat macule periphery). * **Histology:** Look for "bridging" of melanocytic nests, architectural atypia, and lamellar fibroplasia. * **Inheritance:** Often autosomal dominant; associated with mutations in the **CDKN2A** gene on chromosome 9p21.

Q: Acanthosis nigricans associated with malignancy has which of the following characteristics?

Abrupt onset. **Explanation:** Acanthosis Nigricans (AN) is a dermatosis characterized by velvety, hyperpigmented plaques. While most cases are associated with insulin resistance (Type 2 Diabetes, PCOS), **Malignant Acanthosis Nigricans (MAN)** is a distinct paraneoplastic syndrome. **Why "Abrupt Onset" is correct:** Unlike the benign form, which progresses slowly over years, MAN is characterized by a **rapid and extensive onset**. The lesions appear suddenly, spread quickly, and are often more severe (florid). This occurs due to the secretion of Transforming Growth Factor-alpha (TGF-α) by tumor cells, which stimulates epidermal keratinocytes and fibroblasts. **Analysis of Incorrect Options:** * **A & D (Localized/Neck and Axilla only):** Benign AN typically involves the neck and axilla. In contrast, MAN is **generalized and extensive**, often involving unusual sites such as the palms and soles (Tripe palms), oral mucosa, and even the vermilion border of the lips. * **C (Spontaneous resolution):** MAN does not resolve spontaneously. It only regresses if the underlying primary malignancy is successfully treated (surgical resection or chemotherapy). **High-Yield Clinical Pearls for NEET-PG:** * **Most Common Association:** Gastric Adenocarcinoma (up to 60% of cases). * **Tripe Palms:** Velvety, rugose thickening of the palms; highly suggestive of internal malignancy (Lung or Gastric). * **Leser-Trélat Sign:** Sudden eruption of multiple seborrheic keratoses; often co-exists with MAN. * **Clinical Clue:** If AN appears in a non-obese, elderly patient with weight loss, always investigate for an internal malignancy.

Q: A flesh-colored, dome-shaped, 1.2-cm nodule has appeared on the right earlobe of a 60-year-old man in the past month. A central keratin-filled crater is surrounded by proliferating squamous epithelium. This lesion regresses over the next month and then disappears. Which of the following diagnoses is most appropriate for this lesion?

Keratoacanthoma. ### Explanation **Correct Answer: D. Keratoacanthoma** **Why it is correct:** Keratoacanthoma (KA) is a rapidly growing, well-differentiated squamous neoplasm. The clinical presentation in this case is classic: a **rapidly enlarging** (within weeks), **dome-shaped nodule** with a characteristic **central keratinous plug (crateriform)**. A hallmark feature of KA, which distinguishes it from most other skin malignancies, is its tendency for **spontaneous involution** (regression), often leaving a slightly depressed scar. Histologically, it shows proliferating squamous epithelium with a central crater of keratin. **Why other options are incorrect:** * **A. Basal Cell Carcinoma (BCC):** While BCC is common on sun-exposed areas like the ear, it typically presents as a slow-growing pearly papule with telangiectasia and central ulceration (rodent ulcer). It does **not** regress spontaneously. * **B. Seborrheic Keratosis:** These are benign "stuck-on" warty lesions with horn cysts. They do not have a central keratin crater and do not disappear on their own. * **C. Actinic Keratosis:** This is a premalignant lesion presenting as a rough, sandpaper-like erythematous scale. It is not a large dome-shaped nodule and does not follow a rapid growth-and-regression cycle. **High-Yield Clinical Pearls for NEET-PG:** * **Growth Phases:** KA has three phases: Proliferative (rapid growth), Mature (stable crater), and Involutional (spontaneous resolution). * **Association:** Multiple keratoacanthomas are associated with **Muir-Torre syndrome** (a variant of Lynch syndrome). * **Pathology Note:** Histologically, KA can be very difficult to distinguish from well-differentiated Squamous Cell Carcinoma (SCC). Many dermatopathologists consider it a subtype of SCC. * **Treatment:** Despite potential regression, surgical excision is usually recommended because it is clinically difficult to rule out SCC.

Q: Which of the following substances is used as biological therapy for malignant melanoma?

IL-2. **Explanation:** **Interleukin-2 (IL-2)** is a cytokine that plays a critical role in the immune system by stimulating the proliferation and activation of T-cells and Natural Killer (NK) cells. In the context of **Malignant Melanoma**, high-dose IL-2 was one of the first effective biological therapies (immunotherapies) approved. It works by enhancing the body’s own immune surveillance to recognize and destroy melanoma cells. While newer agents like Checkpoint Inhibitors (Pembrolizumab, Nivolumab) are now more common, IL-2 remains a classic high-yield answer for biological therapy in melanoma. **Analysis of Incorrect Options:** * **Infliximab:** This is a chimeric monoclonal antibody against **TNF-alpha**. It is used to treat autoimmune and inflammatory conditions like Psoriasis, Rheumatoid Arthritis, and Crohn’s disease. It is not used for malignancy; in fact, TNF-inhibitors may theoretically increase the risk of certain skin cancers. * **Etanercept:** This is a soluble **TNF-alpha receptor fusion protein**. Like Infliximab, it is used for chronic inflammatory dermatoses (e.g., Psoriatic Arthritis) and is not a treatment for melanoma. **Clinical Pearls for NEET-PG:** * **Targeted Therapy:** If the question mentions a **BRAF V600E mutation**, the drugs of choice are **Vemurafenib** or Dabrafenib. * **Checkpoint Inhibitors:** **Ipilimumab** (anti-CTLA-4) and **Nivolumab/Pembrolizumab** (anti-PD-1) are the modern mainstays of melanoma immunotherapy. * **Prognostic Factor:** The most important prognostic factor for a primary melanoma lesion is the **Breslow Depth** (vertical thickness in mm). * **S-100 & HMB-45:** These are the key immunohistochemical markers used to identify melanoma histologically.

Q: A 40-year-old man presents with a single erythematous plaque on the penis. Histologic examination reveals dysplastic cells throughout the epidermis. Which of the following statements about the disease is FALSE?

Transformation to invasive carcinoma is common. **Diagnosis: Erythroplasia of Queyrat (Squamous Cell Carcinoma in situ of the Penis)** The clinical presentation of a solitary erythematous plaque on the glans penis or prepuce in an uncircumcised male, combined with histology showing full-thickness epidermal dysplasia, confirms a diagnosis of **Erythroplasia of Queyrat (EQ)**. **Explanation of the Correct Answer:** * **Option C is FALSE:** While Erythroplasia of Queyrat is a precursor to invasive squamous cell carcinoma (SCC), the rate of transformation is relatively low, occurring in approximately **10%** of cases. Therefore, saying transformation is "common" is clinically inaccurate. **Analysis of Incorrect Options:** * **Option A (True):** By definition, "in situ" carcinoma means the dysplastic cells are confined to the epidermis and have **not** breached the basement membrane. * **Option B (True):** This condition typically affects older, uncircumcised males. Chronic irritation, accumulation of smegma, and lack of hygiene are significant risk factors. * **Option D (True):** There is a strong oncogenic association with **High-Risk HPV (types 16 and 18)**, which integrate into the host genome and inactivate tumor suppressor genes (p53 and Rb). **High-Yield NEET-PG Pearls:** * **Bowen’s Disease vs. Erythroplasia of Queyrat:** Both are SCC in situ. Bowen’s disease occurs on keratinized skin (scaly plaque), while EQ occurs on mucosal/glans surfaces (velvety red plaque). * **Bowenoid Papulosis:** Presents as multiple pigmented papules; histologically similar to SCC in situ but clinically benign and rarely progresses to malignancy. * **Histology:** Look for "windblown appearance" (disordered maturation), pleomorphic nuclei, and frequent mitoses. * **Treatment of choice:** Mohs micrographic surgery or topical 5-Fluorouracil/Imiquimod.

Q: Hemangiomas are associated with all of the following conditions, except?

Cowden's syndrome. **Explanation:** The correct answer is **Cowden’s syndrome**. **Cowden’s syndrome** is an autosomal dominant condition caused by mutations in the **PTEN gene**. It is characterized by multiple hamartomas (benign growths) in various tissues and an increased risk of malignancies (breast, thyroid, endometrial). While it involves vascular malformations, it is **not** typically associated with true hemangiomas. **Analysis of other options:** * **Rendu-Osler-Weber syndrome (Hereditary Hemorrhagic Telangiectasia):** This is characterized by multiple telangiectasias and arteriovenous malformations (AVMs) in the skin, mucous membranes, and visceral organs (lungs, liver, brain). * **Sturge-Weber Syndrome (Encephalotrigeminal Angiomatosis):** This involves a classic **Port-wine stain** (a capillary malformation/hemangioma) in the distribution of the trigeminal nerve, along with leptomeningeal angiomas and glaucoma. * **Kasabach-Merritt syndrome:** This is a life-threatening condition where a rapidly growing vascular tumor (usually a **Tufted Angioma** or **Kaposiform Hemangioendothelioma**) leads to consumptive coagulopathy and severe thrombocytopenia due to platelet trapping within the lesion. **High-Yield Clinical Pearls for NEET-PG:** * **PHACE Syndrome:** A high-yield association with large segmental infantile hemangiomas (Posterior fossa malformations, Hemangiomas, Arterial anomalies, Cardiac defects, Eye anomalies). * **Treatment of Choice:** Oral **Propranolol** is now the first-line treatment for complicated infantile hemangiomas. * **Kasabach-Merritt:** Remember it presents with "Tumor + Thrombocytopenia + Consumptive Coagulopathy."

Question 1

Which of the following statements about squamous cell carcinoma are true?

Accepted Answer

It is the most common skin tumor seen in transplant patients.

Answer

It is a commoner malignant skin tumor than basal cell carcinoma.

Answer

It occurs only in the skin.

Answer

Metastasis is usually to the regional lymph nodes.

Question 2

Basal cell carcinoma commonly spreads by?

Accepted Answer

Direct spread

Answer

Lymphatics

Answer

Haematogenous

Answer

All the above

Question 3

A male presents with multiple soft, non-fixed swellings over his body and a positive family history. What is the most likely diagnosis?

Accepted Answer

Muir-Torre syndrome

Answer

Dercum's disease

Answer

Multiple Endocrine Neoplasia (MEN)

Answer

Pierre Robin syndrome

Question 4

A 19-year-old man has a pigmented skin lesion. Which of the following characteristics suggests a dysplastic nevus (atypical mole) rather than a benign acquired nevus?

Accepted Answer

Location on the buttock

Answer

Uniform tan color

Answer

4 mm in diameter

Answer

20 similar lesions on the body

Question 5

Acanthosis nigricans associated with malignancy has which of the following characteristics?

Accepted Answer

Abrupt onset

Answer

Localized skin involvement

Answer

Spontaneous resolution

Answer

Involvement of neck and axilla only

Question 6

A flesh-colored, dome-shaped, 1.2-cm nodule has appeared on the right earlobe of a 60-year-old man in the past month. A central keratin-filled crater is surrounded by proliferating squamous epithelium. This lesion regresses over the next month and then disappears. Which of the following diagnoses is most appropriate for this lesion?

Accepted Answer

Keratoacanthoma

Answer

Basal cell carcinoma

Answer

Seborrheic keratosis

Answer

Actinic keratosis

Question 7

Which of the following substances is used as biological therapy for malignant melanoma?

Accepted Answer

IL-2

Answer

Infliximab

Answer

Etanercept

Answer

All of the above

Question 8

Hyperkeratosis of the palms and soles is seen in which of the following conditions?

Accepted Answer

Carcinoma of the esophagus

Answer

Carcinoma of the colon

Answer

Hepatoma

Answer

Adenocarcinoma of the lung

Question 9

A 40-year-old man presents with a single erythematous plaque on the penis. Histologic examination reveals dysplastic cells throughout the epidermis. Which of the following statements about the disease is FALSE?

Accepted Answer

Transformation to invasive carcinoma is common

Answer

Intact basement membrane

Answer

Occurs in older uncircumcised males

Answer

Strong association with HPV types 16 and 18

Question 10

Hemangiomas are associated with all of the following conditions, except?

Accepted Answer

Cowden's syndrome

Answer

Rendu-Osler-Weber syndrome

Answer

Sturge-Weber Syndrome

Answer

Kasabach-Merritt syndrome

Skin Tumors — MCQs

Skin Tumors — MCQs

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