Skin Tumors Practice Questions

Q: Pilomatrixoma is:

a benign epithelial tumor. **Explanation:** **Pilomatrixoma** (also known as Calcifying Epithelioma of Malherbe) is a **benign epithelial tumor** derived from the hair follicle matrix. It typically presents as a firm, solitary, subcutaneous nodule, most commonly on the head, neck, or upper extremities of children and young adults. * **Why Option C is correct:** It is histologically characterized by a dual population of cells: peripheral **basaloid cells** (proliferating component) and central **shadow cells** (or ghost cells), which are necrotic epithelial cells that have lost their nuclei but retained their cytoplasmic outlines. This origin from the hair matrix confirms its status as a benign epithelial neoplasm. * **Why Options A & B are incorrect:** While it may appear as a mass, "fleshy skin mass" is a non-specific clinical description, not a pathological classification. A skin tag (acrochordon) is a benign fibroepithelial polyp, which is structurally and histologically distinct from a follicular matrix tumor. * **Why Option D is incorrect:** Pilomatrixomas are inherently benign. Its malignant counterpart, the **Pilomatrix carcinoma**, is extremely rare. **High-Yield Clinical Pearls for NEET-PG:** 1. **Teeter-totter Sign:** Pressing on one edge of the lesion causes the other edge to protrude (due to its firm, calcified nature). 2. **Tent Sign:** Stretching the overlying skin reveals multiple facets and angles. 3. **Calcification:** Occurs in approximately 75-80% of cases, making the lesion feel "rock hard." 4. **Association:** Multiple pilomatrixomas are associated with **Myotonic Dystrophy** and Gardner Syndrome.

Q: What is the most common malignancy observed in individuals undergoing immunosuppressive therapy?

Skin malignancy. **Explanation:** The correct answer is **Skin malignancy**. Immunosuppression, whether due to organ transplantation (post-transplant medications), HIV/AIDS, or chronic corticosteroid use, significantly increases the risk of developing cancers. Among these, **skin cancers** are the most frequent, occurring at a rate much higher than in the general population. **Why Skin Malignancy is Correct:** The primary reason is the loss of **immune surveillance**. T-cells normally identify and destroy cells with DNA damage caused by UV radiation. In immunosuppressed patients, this mechanism fails. Specifically, **Squamous Cell Carcinoma (SCC)** is the most common skin cancer in this group, often reversing the usual Basal Cell Carcinoma (BCC) to SCC ratio from 4:1 to 1:4. Human Papillomavirus (HPV) also plays a synergistic role in promoting these cutaneous malignancies. **Why Other Options are Incorrect:** * **Lung and Kidney Malignancies:** While the risk of solid organ tumors does increase slightly with immunosuppression, their incidence does not surpass that of skin cancers. * **Hodgkin Lymphoma:** Immunosuppressed patients (especially those with HIV) have a high risk of **Non-Hodgkin Lymphoma (NHL)** and Kaposi Sarcoma, but skin cancers remain numerically more common overall. **NEET-PG High-Yield Pearls:** * **Most common skin cancer in immunosuppressed:** Squamous Cell Carcinoma (SCC). * **Most common skin cancer in the general population:** Basal Cell Carcinoma (BCC). * **Key Risk Factor:** UV radiation exposure combined with drugs like Azathioprine or Cyclosporine. * **Clinical Tip:** Post-transplant patients require lifelong, rigorous dermatological screening due to the aggressive nature of SCC in this demographic.

Q: Which of the following melanomas does not have an in situ growth phase?

Nodular melanoma. **Explanation:** The growth of cutaneous melanoma is categorized into two phases: the **Radial Growth Phase (RGP)** and the **Vertical Growth Phase (VGP)**. The radial phase represents the "in situ" or intraepidermal stage where the tumor spreads horizontally within the epidermis before invading the deeper dermis. **Nodular Melanoma (NM)** is unique because it lacks an identifiable radial/in situ growth phase. From its inception, it exhibits a **Vertical Growth Phase**, characterized by the downward invasion of malignant melanocytes into the dermis. This rapid vertical progression is why NM typically presents as a fast-growing, deeply invasive nodule with a poorer prognosis compared to other subtypes. **Analysis of Other Options:** * **Superficial Spreading Melanoma (SSM):** The most common subtype; it has a prominent radial growth phase that can last for months to years before entering the vertical phase. * **Lentigo Maligna Melanoma (LMM):** Occurs on sun-damaged skin (especially the face of the elderly). It has a very prolonged in situ phase (Lentigo Maligna) that can last decades. * **Desmoplastic Melanoma:** A rare variant often associated with Lentigo Maligna; it typically evolves from an in situ precursor, though its dermal component is characterized by dense fibrosis. **NEET-PG High-Yield Pearls:** * **Most common melanoma overall:** Superficial Spreading Melanoma. * **Melanoma with the worst prognosis:** Nodular Melanoma (due to early VGP). * **Most common site for SSM:** Back (males), Lower limbs (females). * **Breslow’s Depth:** The most important prognostic factor for melanoma (measures the thickness from the granular layer to the deepest tumor cell). * **ABCDE Criteria:** Asymmetry, Border irregularity, Color variegation, Diameter >6mm, Evolving.

Q: Which type of carcinoma characteristically shows no or minimal metastasis?

Basal cell carcinoma. **Basal Cell Carcinoma (BCC)** is the most common skin cancer and is characterized by its **locally invasive** nature but extremely low metastatic potential (less than 0.1%). The underlying medical concept is that BCC cells are dependent on their surrounding stroma (growth factors and extracellular matrix) for survival. Once they detach and enter the lymphatic or vascular systems, they typically undergo apoptosis, preventing distant spread. **Analysis of Options:** * **Squamous Cell Carcinoma (SCC):** Unlike BCC, SCC has a significant risk of metastasis (approx. 2–5%), particularly when occurring on the lips, ears, or in chronic scars (Marjolin’s ulcer). * **Melanoma:** This is the most aggressive skin malignancy. It has a high propensity for early lymphatic and hematogenous spread, making it the leading cause of death from skin cancer. * **Leydig’s Cell Carcinoma:** This is a rare testicular tumor. While many are benign, the malignant variants are known to metastasize to retroperitoneal lymph nodes and distant organs. **High-Yield NEET-PG Pearls:** * **"Rodent Ulcer":** A clinical term for BCC because it "eats away" local tissue (bone and cartilage) if left untreated. * **Commonest Site:** The face, specifically above the line joining the tragus to the angle of the mouth (inner canthus is a high-risk site). * **Histology:** Look for **"Peripheral Palisading"** of nuclei and **"Retraction Artifacts"** (clefts between tumor nests and stroma). * **Treatment of Choice:** Surgical excision or Mohs Micrographic Surgery (for high-risk areas).

Q: Prognosis of malignant melanoma depends on which of the following factors?

Depth of invasion. **Explanation:** The prognosis of malignant melanoma is primarily determined by the **depth of invasion**, which is the most significant independent prognostic factor for localized disease. This is clinically quantified using the **Breslow Depth (Thickness)**. 1. **Why "Depth of Invasion" is correct:** The Breslow thickness measures the distance from the granular layer of the epidermis to the deepest point of tumor involvement in millimeters. As the depth increases, the likelihood of the tumor accessing dermal lymphatics and blood vessels increases, directly correlating with a higher risk of metastasis and lower survival rates. 2. **Why other options are incorrect:** * **Grade of tumor:** Unlike squamous cell carcinoma, "grading" (degree of differentiation) is not a standard prognostic tool for melanoma. * **Spread of tumor:** While spread (local or regional) is important, the initial management and survival prediction are most accurately dictated by the primary tumor's depth. * **Metastasis:** While the presence of metastasis indicates a poor prognosis (Stage IV), it is a *stage* of the disease rather than the primary *factor* used to determine the risk and surgical management of a primary lesion. **High-Yield Clinical Pearls for NEET-PG:** * **Breslow Depth:** The most important prognostic factor (measured in mm). * **Clark Level:** Measures the anatomical level of invasion (e.g., papillary vs. reticular dermis). It is now considered less reliable than Breslow depth. * **TNM Staging:** The 'T' (Tumor) stage in melanoma is defined by Breslow thickness and the presence/absence of **ulceration** (the second most important prognostic factor). * **Sentinel Lymph Node Biopsy (SLNB):** Usually indicated if Breslow thickness is **>0.8 mm** or if ulceration is present. * **Most common site:** Back (men), Legs (women). * **Most common type:** Superficial spreading melanoma.

Q: Which of the following features is most commonly seen?

Actinic keratoses. ***Actinic keratoses*** - Most common **pre-malignant skin lesion** in sun-exposed individuals, with **rough, scaly texture** on sun-damaged skin. - High prevalence in elderly populations with chronic **UV exposure**, representing the most frequently encountered lesion in dermatology practice. *Seborrheic keratoses* - **Benign lesions** with no malignant potential, appearing as **waxy, stuck-on plaques** typically on the trunk. - Less common than actinic keratoses and not associated with **sun exposure** or pre-malignant changes. *Molluscum contagiosum* - **Viral infection** caused by **poxvirus**, presenting as small **umbilicated papules** primarily in children. - Much less common than actinic keratoses and represents an **infectious process** rather than a sun-related lesion. *Basal cell carcinoma* - **Malignant tumor** that is less common than actinic keratoses, presenting as **pearly papules** with telangiectasia. - While the most common **skin cancer**, it occurs less frequently than the pre-malignant actinic keratoses in the general population.

Q: A 78-year-old woman has multiple long-standing lesions on her face and back. These well-circumscribed lesions are tan to brownish, slightly raised with a rough surface, and typically 0.5 to 1.5 cm in diameter. The clinician examining the patient is able to "peel away" parts of the lesion with the dull side of a scalpel blade. Which of the following diagnoses is most likely?

Seborrheic keratoses. **Explanation:** The clinical presentation describes **Seborrheic Keratosis (SK)**, a very common benign epidermal tumor seen in elderly individuals. The key diagnostic features in this vignette are the "stuck-on" appearance, the tan-to-brown color, and the characteristic **friability**. The ability to "peel away" or scrape off the greasy, waxy surface with a dull blade is a classic clinical sign of SK, reflecting its superficial nature and lack of deep dermal involvement. **Why the other options are incorrect:** * **Eczema:** Typically presents as pruritic, erythematous, ill-defined scaly patches or plaques. It does not form discrete, well-circumscribed, "stuck-on" pigmented nodules. * **Melanoma:** While melanoma can be pigmented, it is usually characterized by the ABCDE criteria (Asymmetry, Border irregularity, Color variegation, Diameter >6mm, and Evolution). Melanoma is an invasive malignancy and cannot be "peeled away" with a dull blade. * **Psoriasis:** Presents as well-demarcated erythematous plaques with silvery-white scales. While it shows the **Auspitz sign** (pinpoint bleeding upon scale removal), the lesions are not typically tan/brown or "stuck-on" in appearance. **High-Yield NEET-PG Pearls:** * **Histopathology:** Characterized by small, basaloid cells, hyperkeratosis, and pathognomonic **Horn cysts** (pseudo-horn cysts). * **Leser-Trélat Sign:** The sudden eruption of multiple seborrheic keratoses associated with internal malignancy (most commonly **Gastric Adenocarcinoma**). * **Dermatosis Papulosa Nigra:** A variant of SK seen in dark-skinned individuals, presenting as multiple small, hyperpigmented papules on the malar area. * **Treatment:** Usually unnecessary unless for cosmetic reasons; options include cryotherapy, curettage, or shave excision.

Q: Which of the following cutaneous malignancies does not metastasize through the lymphatics?

Basal cell carcinoma. **Explanation:** **Basal Cell Carcinoma (BCC)** is the correct answer because it is characterized by **local invasiveness** rather than metastatic potential. While it can be highly destructive to local tissues (earning it the name "Rodent Ulcer"), the rate of metastasis is extremely low (0.0028% to 0.5%). When metastasis does rarely occur, it is usually via the lymphatic route, but for the purposes of NEET-PG, BCC is classically defined as a tumor that "destroys locally but does not spread distantly." **Analysis of Incorrect Options:** * **Squamous Cell Carcinoma (SCC):** Unlike BCC, SCC has a significant risk of metastasis (approx. 2–5%), primarily through the **lymphatic system** to regional lymph nodes. * **Melanoma:** This is the most aggressive cutaneous malignancy. It spreads early and rapidly via both **lymphatics** (sentinel node involvement is a key prognostic factor) and hematogenous routes. * **Kaposi’s Sarcoma:** This is a vascular neoplasm caused by HHV-8. It frequently involves the **lymphatic channels** and can present with lymphadenopathy and visceral involvement. **High-Yield Clinical Pearls for NEET-PG:** * **BCC Origin:** Derived from the non-keratinizing cells of the basal layer of the epidermis. * **Most Common Site:** Face (above the line joining the angle of the mouth to the tragus). * **Histopathology:** Look for **"Peripheral Palisading"** of nuclei and retraction artifacts. * **Gold Standard Treatment:** Mohs Micrographic Surgery (highest cure rate). * **Inheritance:** Associated with **Gorlin Syndrome** (PTCH gene mutation).

Q: An HIV-positive patient presents with a characteristic lesion on the leg and a history of HHV-8 infection. What is the most likely diagnosis?

Kaposi sarcoma. **Explanation:** The clinical presentation of an HIV-positive patient with skin lesions and a confirmed **Human Herpesvirus-8 (HHV-8)** infection is the classic diagnostic triad for **Kaposi Sarcoma (KS)**. **Why Kaposi Sarcoma is correct:** Kaposi Sarcoma is a multicentric vascular neoplasm caused by HHV-8 (also known as KSHV). In the context of HIV/AIDS, it is an **AIDS-defining illness**. The virus infects endothelial cells, leading to spindle cell proliferation and neoangiogenesis. Lesions typically present as non-blanching, violaceous (purple) macules, plaques, or nodules, most commonly on the lower extremities, face, or oral mucosa. **Why other options are incorrect:** * **Lymphoma / Non-Hodgkin's Lymphoma (NHL):** While HIV patients are at a higher risk for NHL (e.g., Diffuse Large B-cell Lymphoma or Burkitt Lymphoma), these typically present as lymphadenopathy or systemic symptoms rather than characteristic vascular skin lesions associated with HHV-8. * **Malignant Melanoma:** This is a malignancy of melanocytes. While it presents as pigmented skin lesions, it is not etiologically linked to HHV-8 or specifically triggered by the HIV virus. **High-Yield Clinical Pearls for NEET-PG:** * **Histopathology:** Look for "spindle-shaped cells," "slit-like vascular spaces" containing RBCs, and "promontory sign." * **Variants:** There are four types: Classic (elderly Mediterranean men), Endemic (African), Iatrogenic (transplant-related), and Epidemic (AIDS-associated). * **Treatment:** Highly Active Antiretroviral Therapy (HAART) is the first line for AIDS-related KS. Localized lesions can be treated with intralesional vinblastine or cryotherapy. * **Differential Diagnosis:** Bacillary Angiomatosis (caused by *Bartonella henselae*), which also presents with purple nodules in HIV patients but shows neutrophilic infiltrate on biopsy.

Q: Which is considered the most severe form of malignant melanoma?

Nodular infiltrating type. **Explanation:** **Nodular Melanoma (NM)** is considered the most aggressive and severe form of malignant melanoma because it lacks a **radial growth phase**. Unlike other types that spread horizontally along the epidermis first, NM begins with an immediate **vertical growth phase**. This leads to rapid deep dermal invasion (increased Breslow thickness) and early lymphatic or hematogenous metastasis. Clinically, it presents as a rapidly enlarging, darkly pigmented, or amelanotic "berry-like" nodule. **Analysis of Options:** * **A. Superficially spreading:** This is the **most common** type of melanoma overall. It has a prolonged radial growth phase (months to years), making it easier to detect early and providing a better prognosis than the nodular type. * **C. Lower limb:** While the lower limb is a common site for melanoma (especially in females), the anatomical location alone does not determine severity as much as the histological subtype and depth of invasion. * **D. Choroid:** Uveal (choroidal) melanoma is the most common primary intraocular tumor. While serious, it is a localized variant and not the most common or aggressive form when compared to the systemic impact of nodular cutaneous melanoma. **High-Yield Clinical Pearls for NEET-PG:** * **Breslow Thickness:** The most important prognostic factor in melanoma (measures vertical depth in mm). * **ABCDE Criteria:** Used for early detection (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving). * **Lentigo Maligna:** The type with the best prognosis (slowest growth). * **Acral Lentiginous Melanoma:** The most common type in dark-skinned individuals (palms, soles, subungual).

Question 1

Pilomatrixoma is:

Accepted Answer

a benign epithelial tumor

Answer

a fleshy skin mass

Answer

a type of skin tag

Answer

a malignant skin neoplasm

Question 2

What is the most common malignancy observed in individuals undergoing immunosuppressive therapy?

Accepted Answer

Skin malignancy

Answer

Lung malignancy

Answer

Hodgkin lymphoma

Answer

Kidney malignancy

Question 3

Which of the following melanomas does not have an in situ growth phase?

Accepted Answer

Nodular melanoma

Answer

Superficial spreading melanoma

Answer

Lentigo maligna melanoma

Answer

Desmoplastic melanoma

Question 4

Which type of carcinoma characteristically shows no or minimal metastasis?

Accepted Answer

Basal cell carcinoma

Answer

Squamous cell carcinoma

Answer

Melanoma

Answer

Leydig's cell carcinoma

Question 5

Prognosis of malignant melanoma depends on which of the following factors?

Accepted Answer

Depth of invasion

Answer

Grade of tumor

Answer

Spread of tumor

Answer

Metastasis

Question 6

Which of the following features is most commonly seen?

Accepted Answer

Actinic keratoses

Answer

Seborrheic keratoses

Answer

Molluscum contagiosum

Answer

Basal cell carcinoma

Question 7

A 78-year-old woman has multiple long-standing lesions on her face and back. These well-circumscribed lesions are tan to brownish, slightly raised with a rough surface, and typically 0.5 to 1.5 cm in diameter. The clinician examining the patient is able to "peel away" parts of the lesion with the dull side of a scalpel blade. Which of the following diagnoses is most likely?

Accepted Answer

Seborrheic keratoses

Answer

Eczema

Answer

Melanoma

Answer

Psoriasis

Question 8

Which of the following cutaneous malignancies does not metastasize through the lymphatics?

Accepted Answer

Basal cell carcinoma

Answer

Squamous cell carcinoma

Answer

Melanoma

Answer

Kaposi's sarcoma

Question 9

An HIV-positive patient presents with a characteristic lesion on the leg and a history of HHV-8 infection. What is the most likely diagnosis?

Accepted Answer

Kaposi sarcoma

Answer

Lymphoma

Answer

Malignant melanoma

Answer

Non-Hodgkin's lymphoma

Question 10

Which is considered the most severe form of malignant melanoma?

Accepted Answer

Nodular infiltrating type

Answer

Superficially spreading

Answer

Those arising in the lower limb

Answer

Those in the choroid

Skin Tumors — MCQs

Skin Tumors — MCQs

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