Skin Tumors Practice Questions

Q: Which of the following are premalignant conditions of the skin?

All of the above. **Explanation:** Premalignant conditions (or precancerous lesions) are skin changes that have the potential to progress into invasive squamous cell carcinoma (SCC) or other malignancies if left untreated. * **Bowen’s Disease:** This is defined as **Squamous Cell Carcinoma in situ**. It involves full-thickness dysplasia of the epidermis without invasion through the dermo-epidermal junction. If untreated, it can progress to invasive SCC in approximately 3-5% of cases. * **Paget’s Disease of the Nipple:** This is an intraepidermal adenocarcinoma. While often associated with an underlying invasive ductal carcinoma or DCIS of the breast, the lesion itself represents a malignant transformation within the epidermis, making it a critical "warning" sign of malignancy. * **Leukoplakia:** This is a clinical term for a white patch on the mucosa (often oral) that cannot be rubbed off. It is a classic premalignant condition; histologically, it shows epithelial dysplasia and has a significant risk of transforming into oral SCC. **Clinical Pearls for NEET-PG:** 1. **Actinic Keratosis:** The most common premalignant skin lesion, caused by chronic UV exposure. It is a precursor to SCC. 2. **Erythroplasia of Queyrat:** This is Bowen’s disease occurring specifically on the glans penis. 3. **Arsenic exposure:** A high-yield risk factor for developing multiple Bowen’s disease lesions. 4. **Marjolin’s Ulcer:** An invasive SCC arising in a chronic scar or long-standing burn wound (also a premalignant state). 5. **Xeroderma Pigmentosum:** An autosomal recessive condition with defective DNA repair, leading to multiple premalignant and malignant skin tumors at a young age.

Q: Which of the following conditions is related to sunlight exposure?

Actinic keratosis. **Explanation:** **Actinic Keratosis (AK)** is the correct answer because it is a direct result of cumulative damage to keratinocytes by **Ultraviolet (UV) radiation**. The term "actinic" literally means "caused by light." It is considered a **premalignant lesion** (precursor to Squamous Cell Carcinoma) and typically appears as rough, sandpaper-like scaly plaques on sun-exposed areas like the face, scalp, and dorsum of the hands. **Analysis of Incorrect Options:** * **Molluscum Contagiosum:** This is a viral infection caused by the **Poxvirus**. It presents as umbilicated, pearly papules and is transmitted via direct skin-to-skin contact or fomites, not sunlight. * **Ichthyosis:** This refers to a group of **genetic keratinization disorders** (e.g., Ichthyosis vulgaris) characterized by dry, fish-like scaling. It is hereditary and unrelated to UV exposure. * **Basal Cell Carcinoma (BCC):** While BCC is indeed strongly associated with sunlight, in the context of standard medical examinations, **Actinic Keratosis** is the "most" classic example of a condition defined by its relationship to light (actinic damage). *Note: If this were a multiple-select question, BCC would be correct, but AK is the primary dermatosis specifically named for its solar etiology.* **High-Yield Clinical Pearls for NEET-PG:** * **Histology of AK:** Look for "flag sign" (alternating orthokeratosis and parakeratosis) and cellular atypia in the basal layer of the epidermis. * **Treatment of choice:** Cryotherapy (for single lesions) or Topical **5-Fluorouracil (5-FU)** / Imiquimod (for field cancerization). * **Cutaneous Horn:** AK is the most common underlying cause of a cutaneous horn. * **Risk of Malignancy:** Approximately 0.1% to 10% of AK lesions progress to Squamous Cell Carcinoma (SCC).

Q: Ichthyosis may be associated with which of the following conditions?

Lymphoma. **Explanation:** The association between ichthyosis and systemic disease primarily refers to **Acquired Ichthyosis**. Unlike hereditary forms that appear at birth or in early childhood, acquired ichthyosis develops in adulthood and is frequently a **paraneoplastic manifestation**. **Why Lymphoma is the correct answer:** Acquired ichthyosis is most strongly and classically associated with **Hodgkin’s Lymphoma** (found in up to 70-80% of paraneoplastic cases). It can also occur in Non-Hodgkin’s Lymphoma and Mycosis Fungoides. The skin changes—characterized by symmetric, fish-like scaling—often precede the diagnosis of the malignancy, serving as a crucial clinical marker for underlying lymphoproliferative disorders. **Analysis of Incorrect Options:** * **A & B (Carcinoma of Lung/Breast):** While acquired ichthyosis can rarely be seen with solid tumors (like lung, breast, or colon cancer), these associations are significantly less common than its link with hematological malignancies. * **C (Leukemia):** Although leukemia is a hematological malignancy, the specific association with ichthyosis is far more characteristic of lymphomas. **High-Yield Clinical Pearls for NEET-PG:** * **Acquired Ichthyosis:** If a middle-aged or elderly patient presents with new-onset ichthyosis, the first step is to screen for occult malignancy (specifically Hodgkin’s Lymphoma). * **Non-Malignant Causes:** It can also be associated with hypothyroidism, leprosy, HIV, sarcoidosis, and drugs (e.g., nicotinic acid, clofazimine). * **Histology:** Similar to Ichthyosis Vulgaris, it shows a reduced or absent granular layer. * **Other Paraneoplastic Signs:** Remember other high-yield associations like **Acanthosis Nigricans** (Gastric Adenocarcinoma) and **Leser-Trélat sign** (Internal malignancy).

Q: A 22-year-old patient presents with multiple neural tumors, pigmented iris hamartomas, and numerous tan macules on his skin. His father, paternal uncle, and paternal grandfather had a similar condition. This patient likely suffers from which of the following?

Neurofibromatosis type I. **Explanation:** The clinical presentation of multiple neural tumors (neurofibromas), pigmented iris hamartomas (**Lisch nodules**), and tan macules (**Café-au-lait spots**) is pathognomonic for **Neurofibromatosis Type I (NF1)**, also known as von Recklinghausen disease. The family history (father, uncle, grandfather) confirms an **Autosomal Dominant** inheritance pattern with high penetrance. **Why the other options are incorrect:** * **Ependymoma:** While associated with Neurofibromatosis Type II (NF2), it is not a primary feature of NF1. NF2 is characterized by bilateral acoustic neuromas and lacks Lisch nodules. * **Huntington disease:** An autosomal dominant neurodegenerative disorder characterized by chorea and cognitive decline, not cutaneous or ocular tumors. * **Marfan syndrome:** A connective tissue disorder (FBN1 mutation) presenting with skeletal abnormalities, ectopia lentis, and aortic root dilation, without neural tumors. **High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** NF1 gene is located on **Chromosome 17** (17 letters in Neurofibromatosis); it encodes **Neurofibromin**, a negative regulator of the RAS pathway. * **Diagnostic Criteria (NIH):** Requires 2 or more of: 1. ≥6 Café-au-lait spots (>5mm prepubertal, >15mm postpubertal). 2. ≥2 Neurofibromas or 1 Plexiform neurofibroma. 3. Axillary or inguinal freckling (**Crowe sign**). 4. Optic pathway glioma. 5. ≥2 Lisch nodules (slit-lamp exam). 6. Distinctive osseous lesions (e.g., sphenoid dysplasia). 7. First-degree relative with NF1. * **Associated Malignancy:** Increased risk of Malignant Peripheral Nerve Sheath Tumors (MPNST) and Pheochromocytoma.

Q: What is the most common site for the acral lentigo subtype of malignant melanoma?

Palms and soles. **Explanation:** **Acral Lentiginous Melanoma (ALM)** is a specific histological subtype of malignant melanoma that occurs on the "acral" parts of the body. The term "acral" refers to the distal portions of the limbs. 1. **Why Palms and Soles are correct:** ALM characteristically arises on the **palms, soles, and subungual areas** (under the nails). It is the most common subtype of melanoma in non-Caucasian populations (Asians and African Americans). Unlike other melanomas, its occurrence is **not** related to UV radiation or sun exposure. 2. **Why other options are incorrect:** * **Trunk:** This is the most common site for **Superficial Spreading Melanoma**, particularly in men. * **Face:** This is the classic site for **Lentigo Maligna Melanoma**, which is associated with chronic, cumulative sun damage in elderly patients. * **Buttocks:** This is an uncommon site for melanoma and does not correspond to the "acral" distribution. **High-Yield Clinical Pearls for NEET-PG:** * **Hutchinson’s Sign:** The extension of pigment from the nail matrix onto the proximal or lateral nail fold; it is a crucial clinical clue for subungual ALM. * **ABCDE Rule:** Used for clinical diagnosis (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving). * **Breslow’s Depth:** The most important prognostic factor for melanoma, measuring the vertical thickness of the tumor in millimeters. * **S-100 and HMB-45:** These are the key immunohistochemical markers used to identify melanoma cells.

Q: Which of the following best describes mycosis fungoides?

Cutaneous lymphoma. **Explanation:** **Mycosis Fungoides (MF)** is the most common form of **Cutaneous T-Cell Lymphoma (CTCL)**. Despite its name, it is a malignant neoplastic proliferation of skin-homing CD4+ helper T-cells, not a fungal infection. 1. **Why Option C is Correct:** MF is a primary cutaneous lymphoma where malignant T-lymphocytes infiltrate the skin. Pathologically, it is characterized by **Pautrier’s microabscesses** (clusters of atypical lymphocytes in the epidermis) and "cerebriform" nuclei. It typically progresses through three clinical stages: **Patch → Plaque → Tumor**. 2. **Why Other Options are Incorrect:** * **Option A:** The name "Mycosis Fungoides" was historically coined because the tumor stage resembles mushrooms; however, it has no fungal etiology. Fungal infections of the epidermis are termed dermatophytoses. * **Option B:** MF is a malignancy. If left untreated, it can involve lymph nodes and internal organs (visceral involvement). * **Option D:** While the early "patch stage" can clinically mimic chronic dermatitis or psoriasis, MF is a neoplastic process, not a simple inflammatory dermatitis. **High-Yield Clinical Pearls for NEET-PG:** * **Sezary Syndrome:** The leukemic triad of MF consisting of erythroderma, lymphadenopathy, and atypical circulating T-cells (Sezary cells). * **Hallmark Histology:** Epidermotropism (lymphocytes entering the epidermis without spongiosis). * **Treatment:** Early-stage MF is treated with skin-directed therapies like topical steroids, PUVA (Phototherapy), or Narrowband UVB. Nitrogen mustard is a classic topical chemotherapy used.

Q: Skin cancers develop due to sunlight exposure induced by which type of radiation?

UVB rays. **Explanation:** The primary driver of skin carcinogenesis (Basal Cell Carcinoma, Squamous Cell Carcinoma, and Melanoma) is **UVB radiation (290–320 nm)**. **Why UVB is the correct answer:** UVB rays are often referred to as "burning rays." They are directly absorbed by DNA, leading to the formation of **cyclobutane pyrimidine dimers (CPDs)**, specifically thymine dimers. If these mutations occur in tumor suppressor genes like **p53**, it leads to uncontrolled cell proliferation and skin cancer. While UVB has shorter wavelengths and less penetration than UVA, it is significantly more mutagenic. **Analysis of Incorrect Options:** * **UVA (320–400 nm):** Known as "aging rays," UVA penetrates deeper into the dermis, causing photoaging and indirect DNA damage via reactive oxygen species (ROS). While it contributes to skin cancer, it is less potent than UVB in direct mutagenesis. * **UVC (200–290 nm):** These are the most energetic and lethal rays; however, they are almost entirely absorbed by the Earth’s **ozone layer** and do not reach the skin under normal conditions. * **UVD:** This is a distractor; there is no such classification in the ultraviolet spectrum relevant to clinical dermatology. **High-Yield Clinical Pearls for NEET-PG:** * **Action Spectrum:** UVB is responsible for Vitamin D synthesis, sunburn (erythema), and the majority of non-melanoma skin cancers. * **Signature Mutation:** The "C to T" or "CC to TT" transition is the classic UV-induced mutation signature. * **Xeroderma Pigmentosum:** A condition where patients lack the **nucleotide excision repair (NER)** mechanism to fix UVB-induced pyrimidine dimers, leading to early-onset skin cancers. * **Sunscreen:** SPF (Sun Protection Factor) primarily measures protection against **UVB** rays.

Q: An HIV positive patient presented with the clinical condition as seen in the color plate. Which of the following is the most probable diagnosis?

Kaposi sarcoma. ***Kaposi sarcoma*** - **Kaposi sarcoma** is an **AIDS-defining illness** caused by **HHV-8 (human herpesvirus-8)** and commonly presents as **violaceous (purple-red) plaques or nodules** in HIV-positive patients. - The **immunocompromised state** in HIV patients significantly increases susceptibility to this **vascular tumor**, making it the most probable diagnosis given the clinical context. *Pyogenic Granuloma* - Typically appears as a **red, pedunculated, bleeding lesion** that develops rapidly following trauma or irritation. - Not specifically associated with **HIV infection** or immunocompromised states, and lacks the characteristic **violaceous color** of Kaposi sarcoma. *Linear Gingival Erythema* - Presents as a **distinct red band along the gingival margin** and is a **periodontal condition**, not a tumor. - While it can occur in HIV patients, it manifests as **gingival inflammation** rather than the **nodular skin lesions** typical of Kaposi sarcoma. *Focal Epithelial Hyperplasia* - Caused by **HPV types 13 and 32**, presenting as **multiple small, painless papules** in the oral cavity. - This **benign condition** lacks the **vascular nature** and **violaceous appearance** characteristic of Kaposi sarcoma in HIV patients.

Q: What is the recommended treatment for Stage 1 cutaneous T-cell lymphoma?

PUVA (Psoralen plus Ultraviolet A). **Explanation:** Cutaneous T-cell lymphoma (CTCL), specifically **Mycosis Fungoides (MF)**, is staged based on the extent of skin involvement and systemic spread. Stage 1 (IA and IB) is characterized by patches and plaques involving <10% or ≥10% of the body surface area, respectively, without nodal or visceral involvement. **Why Option A is correct:** For early-stage CTCL (Stage 1), **Skin-Directed Therapy (SDT)** is the first-line treatment. **PUVA (Psoralen plus Ultraviolet A)** is highly effective as it induces apoptosis of the malignant T-cells in the epidermis and dermis. Other SDTs include topical corticosteroids, topical retinoids (Bexarotene), and Narrowband UVB (for thin patches). **Why other options are incorrect:** * **B. Biological response modifiers:** (e.g., Interferon-alpha) are typically reserved for Stage IIB (tumors) or cases refractory to skin-directed therapies. * **C. Systemic chemotherapy:** This is generally avoided in early stages due to toxicity and lack of curative potential. It is reserved for advanced Stage IV disease with visceral involvement. * **D. Extracorporeal photopheresis:** This is the treatment of choice for **Sézary Syndrome** (leukemic phase of CTCL) or erythrodermic MF (Stage III), rather than localized Stage 1 disease. **High-Yield Clinical Pearls for NEET-PG:** * **Pathognomonic feature:** Pautrier’s microabscesses (clusters of atypical T-cells in the epidermis). * **Hallmark cell:** Lutzner cells (T-helper cells with cerebriform nuclei). * **Staging:** Stage IA ( 10% BSA), Stage IIB (Tumors), Stage III (Erythroderma), Stage IV (Visceral/Nodal). * **Treatment Mantra:** "Start local for early stage, systemic for late stage."

Q: A patient presents with pigmented macules on the palm. Histological examination reveals proliferating melanocytes at the dermoepidermal junction. What is the most likely diagnosis?

Junctional nevus. ### Explanation **Correct Option: B. Junctional nevus** The diagnosis is based on the specific anatomical location of the melanocytic proliferation. A **junctional nevus** is characterized histologically by nests or clusters of melanocytes located strictly at the **dermoepidermal junction (DEJ)**. Clinically, these appear as flat (macular), well-circumscribed, and pigmented lesions. They are the most common type of nevus found on **palms, soles, and genitalia**. **Analysis of Incorrect Options:** * **A. Halo nevus:** This is a melanocytic nevus surrounded by a depigmented "halo" caused by an immune-mediated (T-cell) destruction of melanocytes. Histology would show a dense lymphocytic infiltrate. * **C. Dermal melanocytic nevus:** In this type, the melanocytes have migrated entirely into the **dermis**. Clinically, these are typically raised (papular), dome-shaped, and often lose their pigmentation (skin-colored). * **D. Dysplastic nevus:** These show architectural atypia (bridging of nests, shouldering phenomenon) and cytologic atypia. While they involve the junction, the question describes a simple proliferation without features of dysplasia. **High-Yield NEET-PG Pearls:** 1. **Evolution of Nevi:** Nevi often follow a life cycle: Junctional (flat) → Compound (raised/junctional + dermal) → Intradermal (raised/dermal only). 2. **Compound Nevus:** Shows melanocytic nests at both the DEJ and within the dermis. 3. **Abtropfung Effect:** The process where melanocytes "drop off" from the epidermis into the dermis to form a compound or dermal nevus. 4. **Palmar/Plantar Lesions:** Any pigmented macule on acral skin in an adult that shows irregular borders or variegation should be evaluated to rule out **Acral Lentiginous Melanoma**.

Question 1

Which of the following are premalignant conditions of the skin?

Accepted Answer

All of the above

Answer

Bowen disease

Answer

Paget's disease of the nipple

Answer

Leukoplakia

Question 2

Which of the following conditions is related to sunlight exposure?

Accepted Answer

Actinic keratosis

Answer

Molluscum contagiosum

Answer

Ichthyosis

Answer

Basal cell carcinoma

Question 3

Ichthyosis may be associated with which of the following conditions?

Accepted Answer

Lymphoma

Answer

Carcinoma of the lung

Answer

Carcinoma of the breast

Answer

Leukemia

Question 4

A 22-year-old patient presents with multiple neural tumors, pigmented iris hamartomas, and numerous tan macules on his skin. His father, paternal uncle, and paternal grandfather had a similar condition. This patient likely suffers from which of the following?

Accepted Answer

Neurofibromatosis type I

Answer

Ependymoma

Answer

Huntington disease

Answer

Marfan syndrome

Question 5

What is the most common site for the acral lentigo subtype of malignant melanoma?

Accepted Answer

Palms and soles

Answer

Trunk

Answer

Face

Answer

Buttocks

Question 6

Which of the following best describes mycosis fungoides?

Accepted Answer

Cutaneous lymphoma

Answer

Fungal infection of the epidermis

Answer

Benign skin lesion

Answer

Dermatitis

Question 7

Skin cancers develop due to sunlight exposure induced by which type of radiation?

Accepted Answer

UVB rays

Answer

UVA rays

Answer

UVD rays

Answer

UVC rays

Question 8

An HIV positive patient presented with the clinical condition as seen in the color plate. Which of the following is the most probable diagnosis?

Accepted Answer

Kaposi sarcoma

Answer

Pyogenic Granuloma

Answer

Linear Gingival Erythema

Answer

Focal Epithelial Hyperplasia

Question 9

What is the recommended treatment for Stage 1 cutaneous T-cell lymphoma?

Accepted Answer

PUVA (Psoralen plus Ultraviolet A)

Answer

Biological response modifiers

Answer

Systemic chemotherapy

Answer

Extracorporeal photopheresis

Question 10

A patient presents with pigmented macules on the palm. Histological examination reveals proliferating melanocytes at the dermoepidermal junction. What is the most likely diagnosis?

Accepted Answer

Junctional nevus

Answer

Halo nevus

Answer

Dermal melanocytic nevus

Answer

Dysplastic nevus

Skin Tumors — MCQs

Skin Tumors — MCQs

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