Skin Tumors Practice Questions

Q: What is the most common type of skin carcinoma on the face in light-skinned individuals?

Basal cell carcinoma. **Explanation:** **Basal Cell Carcinoma (BCC)** is the most common skin malignancy worldwide and specifically the most common type of skin carcinoma on the face in light-skinned individuals. It typically arises from the basal layer of the epidermis. The primary risk factor is chronic exposure to ultraviolet (UV) radiation. It most frequently occurs on sun-exposed areas, particularly the "upper two-thirds" of the face (above a line joining the angle of the mouth to the earlobe). **Analysis of Options:** * **A. Squamous Cell Carcinoma (SCC):** This is the second most common skin cancer. While also related to sun exposure, it is more common on the "lower third" of the face (e.g., lower lip) and has a higher potential for lymphatic metastasis compared to BCC. * **C. Bowen’s Disease:** This is a clinical term for **Squamous Cell Carcinoma in-situ**. It presents as a slow-growing, red, scaly patch. It is a precursor to invasive SCC, not the most common primary carcinoma. * **D. Erythroplasia of Queyrat:** This is a specific form of SCC in-situ that occurs on the glans penis or prepuce. It is not a facial malignancy. **Clinical Pearls for NEET-PG:** * **Classic Presentation:** A pearly, translucent papule with telangiectasia and a "rolled-out" border. It may centralize to form a "Rodent Ulcer." * **Metastasis:** BCC is locally invasive but **rarely metastasizes**. * **Treatment of Choice:** Surgical excision with safe margins. For high-risk areas (face), **Mohs Micrographic Surgery** is the gold standard to ensure complete margin control while sparing tissue. * **Inherited Syndrome:** Gorlin Syndrome (Basal Cell Nevus Syndrome) is associated with multiple BCCs, odontogenic keratocysts, and bifid ribs.

Q: An 80-year-old man presents with a recently noticed skin lesion. A biopsy was performed, and the histopathology report is available. Which of the following options cannot be used as a management for this clinical scenario?

None of the above. ***None of the above*** - All three treatment options (**Mohs micrographic surgery**, **photodynamic therapy**, and **electrodesiccation**) are valid management modalities for **basal cell carcinoma (BCC)**. - The histopathology shows typical BCC features including **basaloid cell nests**, **peripheral palisading**, and **retraction artifact**, confirming the diagnosis and making all listed treatments appropriate. *Mohs micrographic surgery* - **Gold standard** treatment for BCC, especially for **high-risk locations** (face, ears, genitals) and **recurrent tumors**. - Provides **complete margin assessment** with tissue-sparing technique, achieving cure rates of **95-99%** for primary BCC. *Photodynamic therapy* - **Non-invasive treatment** using **topical photosensitizers** (aminolevulinic acid) followed by **light activation**. - Particularly effective for **superficial BCC** and **multiple lesions**, with excellent **cosmetic outcomes**. *Electrodesiccation* - **Curettage and electrodesiccation** is a standard treatment for **low-risk, small BCCs** on the trunk and extremities. - Involves **scraping the tumor** followed by **electrical cautery**, with cure rates of **85-95%** for appropriate lesions.

Q: What is the most likely diagnosis in this 50-year-old woman?

Metastasis. ***Metastasis*** - **Subungual metastases** in a 50-year-old woman often present as **nail bed destruction** with rapid progression and **digital pain**. - Common primary sites include **lung**, **breast**, and **melanoma**, which can metastasize to the nail bed causing characteristic **nail dystrophy**. *Onychomycosis* - Typically presents with **gradual thickening** and **yellow-brown discoloration** of the nail, not rapid destruction. - Usually affects **multiple nails** and responds to **antifungal therapy**, unlike metastatic lesions. *Psoriasis* - Nail psoriasis shows characteristic **pitting**, **oil spots**, and **onycholysis** with well-defined borders. - Often associated with **skin plaques** and **joint involvement** rather than destructive nail bed lesions. *Thromboangiitis obliterans* - Primarily affects **young male smoers** and causes **digital ischemia** and **gangrene**. - Presents with **claudication** and **ulcerations** rather than isolated nail bed destruction in middle-aged women.

Q: Which of the following is NOT a risk factor for squamous cell carcinoma?

Human papillomavirus (HPV) type 18. **Explanation:** The correct answer is **D. Human papillomavirus (HPV) type 18**. In the context of Squamous Cell Carcinoma (SCC) of the **skin**, HPV types 16 and 18 are primarily associated with mucosal malignancies (like cervical, oropharyngeal, and anal cancers) rather than cutaneous SCC. While HPV types 5 and 8 are linked to skin SCC (especially in patients with Epidermodysplasia verruciformis), HPV 18 is a high-risk mucosal strain and is not considered a standard risk factor for general cutaneous SCC. **Analysis of Options:** * **A. Ultraviolet (UV) radiation:** This is the most significant risk factor for SCC. UV-B radiation causes direct DNA damage and mutations in the **p53 tumor suppressor gene**, leading to keratinocyte transformation. * **B. Tar:** Chemical carcinogens, including coal tar, soot (as seen in Percivall Pott’s chimney sweeps), and arsenic, are well-established triggers for skin SCC. * **C. Tobacco:** Smoking is a systemic risk factor for SCC, particularly of the lip, oral cavity, and lungs. It acts as a potent chemical carcinogen that impairs local immunity and promotes DNA damage. **Clinical Pearls for NEET-PG:** * **Marjolin’s Ulcer:** A highly aggressive SCC arising in chronic scars, non-healing ulcers, or burn sites. * **Precursor Lesions:** Actinic keratosis (most common) and Bowen’s disease (SCC in situ). * **Genetic Association:** Xeroderma Pigmentosum is a high-yield condition where defective nucleotide excision repair leads to early-onset SCC. * **HPV Strains:** Remember **HPV 6, 11** (Low risk - Warts) vs. **HPV 16, 18** (High risk - Cervical/Mucosal SCC).

Q: Which of the following is NOT a risk factor for melanoma?

Black people. **Explanation:** The correct answer is **B. Black people**. Melanoma is significantly more common in individuals with fair skin (Fitzpatrick types I and II) who have less melanin. Melanin acts as a natural photoprotectant against DNA damage. While people with darker skin tones can develop melanoma, their risk is substantially lower than that of Caucasians. When it does occur in Black populations, it often presents as **Acral Lentiginous Melanoma** (affecting palms, soles, and nail beds), which is not primarily linked to UV exposure. **Analysis of other options:** * **A. Exposure to UV radiation:** This is the most significant environmental risk factor. Both cumulative sun exposure and episodes of severe, blistering sunburns (especially during childhood) increase risk. * **C. First-degree relative with melanoma:** Approximately 10% of patients have a family history. Mutations in the **CDKN2A** gene are the most common genetic link identified in familial cases. * **D. Multiple or dysplastic nevi:** Having a high total mole count (>50–100) or the presence of atypical (dysplastic) nevi significantly increases the statistical risk of developing melanoma. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site:** In men, it is the **back**; in women, it is the **lower legs**. * **Prognostic Factor:** The most important prognostic factor for Stage I and II melanoma is **Breslow’s Thickness** (vertical depth in mm). * **ABCDE Criteria:** Used for clinical assessment—**A**symmetry, **B**order irregularity, **C**olor variation, **D**iameter >6mm, and **E**volving/Elevation. * **Biopsy Gold Standard:** Excisional biopsy with a 1–3 mm margin. Never perform a shave biopsy if melanoma is suspected.

Q: Which of the following best describes the characteristic lesion of Kaposi sarcoma?

A raised, purple-red lesion. ***A raised, purple-red lesion*** - Kaposi sarcoma is a vascular tumor caused by **Human Herpesvirus-8 (HHV-8)**, presenting as violaceous (purple-red) macules, papules, or nodules on the skin and mucosa. - These lesions are common in immunocompromised individuals, particularly those with **HIV/AIDS**, and are characterized by the proliferation of endothelial cells. *A yellow lesion containing pus* - This description is characteristic of a **pustule** or an **abscess**, which are typically signs of a bacterial infection, such as those caused by **Staphylococcus aureus**. - Kaposi sarcoma is a neoplastic lesion, not an acute purulent infection, and does not contain pus. *A white, striated lesion that cannot be scraped off* - This is the classic presentation of **oral hairy leukoplakia**, a benign mucosal lesion caused by the **Epstein-Barr virus (EBV)**, also seen in immunocompromised patients. - It differs from Kaposi sarcoma in its color (white vs. purple-red), location (typically lateral tongue), and causative virus. *Small, red erosions* - This description is more consistent with conditions like **herpes simplex virus (HSV)** infection, where vesicles rupture to form erosions, or with erosive inflammatory dermatoses. - Kaposi sarcoma typically manifests as proliferative papules or nodules, not as primary erosions.

Q: An elderly man presents with an ulcerative lesion at the inner canthus of his eye with pearly margins. On microscopic examination, it shows a palisading arrangement of cells. Identify the lesion:

Basal cell carcinoma. ***Basal cell carcinoma*** - The clinical presentation of an ulcerative lesion with **pearly margins**, especially in a sun-exposed area like the inner canthus, is a classic sign of nodular **basal cell carcinoma (BCC)** [1]. - Histologically, the pathognomonic feature is nests of **basaloid cells** with a **peripheral palisading** arrangement, as described and shown in the image [1], [2]. *Squamous cell carcinoma* - **Squamous cell carcinoma (SCC)** typically presents as a scaly, crusted, or erythematous lesion and usually lacks the characteristic **pearly** borders seen in BCC [2]. - Microscopically, SCC is characterized by invasive nests of atypical keratinocytes, often with the formation of **keratin pearls** and intercellular bridges, not palisading [2]. *Keratoacanthoma* - A **keratoacanthoma** is a rapidly growing, dome-shaped tumor with a central, **keratin-filled crater**, which is a distinct clinical feature not described here [2]. - Histologically, it resembles a well-differentiated SCC and does not show the basaloid cells with peripheral palisading characteristic of BCC [2]. *Melanocytic melanoma* - **Melanoma** is a malignancy of melanocytes, typically presenting as a pigmented lesion following the **ABCDE** criteria (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving). - Histology shows atypical melanocytes, not basaloid cells. The cells may contain melanin pigment and have prominent nucleoli, which differs from the microscopic findings in this case. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Skin, pp. 1158-1160. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Disorders Involving Inflammatory And Haemopoietic Cells, pp. 643-645.

Q: A 60-year-old person presented with an ulcer on the medial canthus. The ulcer has rolled-out, beaded margins. Histopathology shows nesting cells with peripheral palisading patterns. What is the most likely diagnosis?

Basal Cell Carcinoma (BCC). ***Basal Cell Carcinoma (BCC)***- The clinical presentation of a slow-growing ulcer with **rolled-out, beaded margins** on a sun-exposed area like the medial canthus is classic for the nodular variant of BCC.- Histopathology showing nests of **basaloid cells** originating from the epidermis, with characteristic **peripheral palisading** of nuclei, is the pathognomonic microscopic description for BCC.*Squamous Cell Carcinoma (SCC)*- SCC often presents as a **firm, hyperkeratotic nodule** or plaque that frequently ulcerates, but it typically lacks the pearly, beaded margins characteristic of BCC.- Histologically, SCC consists of **squamous differentiation**, demonstrating **keratin pearls** and intercellular bridges, not peripheral palisading.*Nevus*- A nevus (mole) is a benign proliferation of **melanocytes**; it is usually a pigmented macule or papule and does not typically present as a destructive ulcer with rolled borders.- Histopathology shows uniform nests of nevus cells, confined to the junction or dermis, lacking the malignant architecture and the **basaloid cells** seen here.*Melanoma*- Melanoma often presents as an **asymmetrical, irregularly bordered**, and variably pigmented lesion (ABCDE criteria), which differs from the non-pigmented ulcer described.- Histopathology would reveal atypical **melanocytes** with characteristic nuclear features and dermal invasion, not the nested, palisading basaloid cells of BCC.

Q: A patient presents with a lesion on the sun-exposed area shown in the image. What is the most likely diagnosis?

Basal cell carcinoma. ***Basal cell carcinoma*** - **Basal cell carcinoma** is the **most common skin cancer**, typically presenting as a **pearly, translucent nodule** with **rolled borders** and **central ulceration** on sun-exposed areas. - It frequently occurs on the **face, scalp, and neck** due to chronic **UV radiation exposure** and has a very low metastatic potential. *Squamous cell carcinoma* - **Squamous cell carcinoma** typically presents as a **red, scaly patch** or **firm, keratotic nodule** that may ulcerate and bleed. - While also common in sun-exposed areas, it has a **higher metastatic potential** than basal cell carcinoma and often arises from **actinic keratoses**. *Melanoma* - **Melanoma** is a less common but highly **aggressive skin cancer** arising from **melanocytes** with significant metastatic potential. - It typically presents as an **atypical mole** with **asymmetry, irregular borders, color variation, and diameter >6mm** (ABCD criteria). *Actinic keratosis* - **Actinic keratosis** is a **precancerous lesion** presenting as **rough, scaly, erythematous patches** on sun-damaged skin. - It represents **dysplastic keratinocytes** that can progress to **squamous cell carcinoma** but is not malignant itself.

Question 1

What is the most common type of skin carcinoma on the face in light-skinned individuals?

Accepted Answer

Basal cell carcinoma

Answer

Squamous cell carcinoma

Answer

Bowen's disease

Answer

Erythroplasia of Queyrat

Question 2

Kaposi sarcoma is commonly seen in which anatomical location?

Accepted Answer

Lower limbs

Answer

Upper limbs

Answer

Head and Neck

Answer

Trunk

Question 3

An 80-year-old man presents with a recently noticed skin lesion. A biopsy was performed, and the histopathology report is available. Which of the following options cannot be used as a management for this clinical scenario?

Accepted Answer

None of the above

Answer

Mohs micrographic surgery

Answer

Photodynamic therapy

Answer

Electrodessication

Question 4

What is the most likely diagnosis in this 50-year-old woman?

Accepted Answer

Metastasis

Answer

Onychomycosis

Answer

Psoriasis

Answer

Thromboangiitis obliterans

Question 5

Which of the following is NOT a risk factor for squamous cell carcinoma?

Accepted Answer

Human papillomavirus (HPV) type 18

Answer

Ultraviolet radiation

Answer

Tar

Answer

Tobacco

Question 6

Which of the following is NOT a risk factor for melanoma?

Accepted Answer

Black people

Answer

Exposure to UV radiation

Answer

First-degree relative with melanoma

Answer

Multiple or dysplastic nevi

Question 7

Which of the following best describes the characteristic lesion of Kaposi sarcoma?

Accepted Answer

A raised, purple-red lesion

Answer

Small, red erosions

Answer

A white, striated lesion that cannot be scraped off

Answer

A yellow lesion containing pus

Question 8

An elderly man presents with an ulcerative lesion at the inner canthus of his eye with pearly margins. On microscopic examination, it shows a palisading arrangement of cells. Identify the lesion:

Accepted Answer

Basal cell carcinoma

Answer

Melanocytic melanoma

Answer

Keratoacanthoma

Answer

Squamous cell carcinoma

Question 9

A 60-year-old person presented with an ulcer on the medial canthus. The ulcer has rolled-out, beaded margins. Histopathology shows nesting cells with peripheral palisading patterns. What is the most likely diagnosis?

Accepted Answer

Basal Cell Carcinoma (BCC)

Answer

Nevus

Answer

Melanoma

Answer

Squamous Cell Carcinoma (SCC)

Question 10

A patient presents with a lesion on the sun-exposed area shown in the image. What is the most likely diagnosis?

Accepted Answer

Basal cell carcinoma

Answer

Squamous cell carcinoma

Answer

Melanoma

Answer

Actinic keratosis

Skin Tumors — MCQs

Skin Tumors — MCQs

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