Skin Tumors Practice Questions

Q: Which procedure is most appropriate for a 0.8cm superficial BCC on the cheek?

Mohs surgery. ***Mohs surgery*** - This procedure is ideal for **BCCs on the face** due to its **tissue-sparing** and **high cure rate** properties. - Its real-time microscopic control ensures complete tumor removal while preserving maximum healthy tissue, which is crucial for cosmetic outcomes on visible areas like the **cheek**. *Curettage and electrodesiccation* - This method is typically used for **smaller, superficial BCCs** on the trunk or extremities, not generally for facial lesions in cosmetically sensitive areas. - It has a **higher recurrence rate** for facial BCCs compared to Mohs surgery due to the lack of margin control. *Cryotherapy* - While effective for some superficial skin lesions, **cryotherapy** can lead to **scarring** and **pigment changes**, which are undesirable on the face. - It also lacks histological confirmation of complete tumor removal, leading to a **higher risk of recurrence** for BCCs. *Excision with 4mm margins* - Standard excision might be appropriate for BCCs on the trunk or extremities, but on the face, a **4mm margin** might lead to a larger cosmetic defect than necessary. - Although it provides histological confirmation, it doesn't offer the same **tissue-sparing advantage** as Mohs surgery for facial lesions, potentially resulting in larger scars.

Q: A patient consults a dermatologist about a skin lesion on her neck. Examination reveals a 1-cm diameter, red, scaly plaque with a rough texture and irregular margins. Biopsy demonstrates epidermal cells with large, pleomorphic, hyperchromatic nuclei. What is the most likely diagnosis?

Actinic keratosis. ***Actinic keratosis*** - This diagnosis aligns with the description of a **red, scaly plaque** with a **rough texture** and **irregular margins**, which are classic clinical features of actinic keratosis. - The biopsy findings of epidermal and dermal cells with **large, pleomorphic, hyperchromatic nuclei** are consistent with **atypical keratinocytes**, a hallmark of actinic keratosis, indicating **premalignant change**. *Dermal nevus* - A dermal nevus is a **benign melanocytic lesion** that typically presents as a smooth, flesh-colored to light brown papule or nodule, not a scaly or rough plaque. - Histologically, it would show nests of nevus cells primarily in the **dermis** without the significant cellular atypia described. *Junctional nevus* - A junctional nevus is a **benign melanocytic lesion** characterized by nests of nevus cells located at the **dermoepidermal junction**. - Clinically, it appears as a flat or slightly raised, well-demarcated macule or papule, usually uniform in color, lacking the scaly, rough, and irregular features of the presented lesion. *Compound nevus* - A compound nevus is a **benign melanocytic lesion** with nevus cell nests present at both the **dermoepidermal junction** and within the dermis. - It typically presents as a raised, pigmented papule or nodule with a smooth or slightly warty surface, not a scaly plaque with irregular margins.

Q: A child presents with linear verrucous plaques on the trunk, accompanied by vacuolization of keratinocytes in the stratum spinosum and stratum granulosum. What is the diagnosis?

Verrucous epidermal nevus. ***Verrucous epidermal nevus*** - The presence of **linear verrucous plaques** on the trunk, coupled with **vacuolization of keratinocytes** in the **stratum spinosum** and **stratum granulosum**, is characteristic of a verrucous epidermal nevus. - These lesions are **benign congenital malformations** of the epidermis that follow the lines of Blaschko. *Incontinentia pigmenti* - This condition presents with **pigmentary changes** (swirling hyperpigmentation) typically in a linear pattern, often preceded by **vesicular and verrucous stages**. - Histologically, it shows **eosinophilic spongiosis** and **dyskeratotic cells** in earlier stages, rather than significant keratinocyte vacuolization in the stratum spinosum and granulosum as the primary finding described here. *Delayed hypersensitivity reaction* - A delayed hypersensitivity reaction (e.g., contact dermatitis) typically presents as **erythema**, **edema**, **pruritus**, and **vesiculation**, without a primary verrucous nature. - Histologically, it would show **spongiosis** (intercellular epidermal edema) and a **lymphocytic infiltrate**, but not the prominent vacuolization described. *Linear Darier's disease* - **Darier's disease** (keratosis follicularis) is characterized by **greasy, hyperkeratotic papules** typically in seborrheic areas; the linear form follows Blaschko's lines. - Histologically, it is defined by **dyskeratosis** (corps ronds and grains) and **acantholysis** (suprabasal clefting), which are distinct from simple keratinocyte vacuolization.

Q: A 50-year-old man presents with a rapidly enlarging, painless nodule on his ear. A biopsy shows keratin pearls and atypical squamous cells. What is the diagnosis?

Squamous cell carcinoma. ***Squamous cell carcinoma*** - The presence of **keratin pearls** and **atypical squamous cells** on biopsy is pathognomonic for **squamous cell carcinoma**. - A **rapidly enlarging, painless nodule** on sun-exposed areas like the ear is a classical presentation for this type of skin cancer. *Basal cell carcinoma* - Characterized by **palisading nuclei** and **peripheral clefting** on histology, not keratin pearls. - Typically presents as a **pearly nodule with telangiectasias**, which differs from the description. *Actinic keratosis* - This is a **precancerous lesion** characterized by **atypical keratinocytes** in the basal epidermal layer, but not invasive growth or true keratin pearls. - While it can progress to squamous cell carcinoma, the biopsy findings here indicate a **frank malignancy**. *Keratoacanthoma* - This lesion can grow rapidly and has a dome-shaped appearance with a **central keratin plug**. - Histologically, it shows **well-differentiated squamous cells** with a distinctive **crater-like architecture** with "lip" configuration, but the presence of **atypical squamous cells** on biopsy favors SCC over this typically benign lesion.

Q: A 70-year-old man presents with a rough, scaly lesion on his face that does not heal. A biopsy shows atypical keratinocytes. What is the diagnosis?

Actinic keratosis. ***Correct: Actinic keratosis*** - A **rough, scaly lesion on sun-exposed skin** (like the face) in an elderly patient is characteristic of actinic keratosis. - A biopsy showing **atypical keratinocytes confined to the lower epidermis** confirms the diagnosis. Actinic keratosis is a pre-malignant lesion representing dysplastic proliferation of keratinocytes. - The atypia is **partial-thickness** (not full-thickness), which distinguishes it from SCC in situ. *Incorrect: Basal cell carcinoma* - BCC typically presents as a **pearly, translucent nodule with telangiectasias** or a **non-healing ulcer with rolled borders**. - Histologically, BCC shows **nests of basaloid cells with peripheral palisading**, not atypical keratinocytes. *Incorrect: Squamous cell carcinoma* - While SCC can appear as a **scaly, crusted, or ulcerated nodule** on sun-exposed areas, biopsy would show **full-thickness epidermal atypia** or **dermal invasion**. - Actinic keratosis is the **precursor lesion to SCC**, but the presence of only atypical keratinocytes without invasion indicates AK rather than invasive SCC. *Incorrect: Seborrheic keratosis* - Seborrheic keratoses are benign lesions with a characteristic **"stuck-on" appearance** and waxy or greasy surface. - Histology shows **proliferation of basaloid cells** and **horn cysts (pseudo-horn cysts)**, not atypical keratinocytes.

Q: A 40-year-old man presents with multiple firm, pink nodules on his trunk. Histopathology reveals a storiform pattern with CD34 positivity. What is the most likely diagnosis?

Dermatofibrosarcoma protuberans. ***Dermatofibrosarcoma protuberans (DFSP)*** - DFSP is characterized by a distinctive **storiform (pinwheel) pattern** of spindle cells on histology. - **CD34 positivity** is a key immunohistochemical marker for DFSP, along with its presentation as a firm, pink nodule on the trunk. *Keloid* - Keloids are benign fibrous growths that result from an overgrowth of **scar tissue** and typically do not show a storiform pattern. - Histologically, keloids are characterized by thick, haphazardly arranged **collagen bundles** and are **CD34 negative**. *Neurofibroma* - Neurofibromas are benign peripheral nerve sheath tumors that exhibit a characteristic **"shredded carrot" collagen pattern** and spindle cells with wavy nuclei. - While they can be CD34 positive, the classic **storiform pattern** seen in this patient is not typical for neurofibroma. *Basal cell carcinoma* - Basal cell carcinoma typically presents with **peripheral palisading** of basaloid cells and stromal retraction, and does not exhibit a storiform pattern. - It is usually **CD34 negative** and often presents with ulceration or pearly borders, which are not described here.

Q: A 34-year-old man presents with a painless, hyperpigmented lesion on the inner aspect of his right thigh that has increased in size over the last 6 months. What is the most likely diagnosis?

Malignant melanoma. ***Malignant melanoma*** - A **painless**, **hyperpigmented lesion** that has **increased in size over 6 months** raises high suspicion for **malignant melanoma**, even in a non-sun-exposed area like the inner thigh. - The **progressive enlargement** over 6 months is the most concerning feature, suggesting malignancy. - Melanomas can occur anywhere on the body, including sites without sun exposure (acral, mucosal, and unexposed skin). - Key features supporting melanoma: **evolving size** (E of ABCDE criteria) and **hyperpigmentation** suggesting melanocytic origin. - **Definitive diagnosis requires biopsy** with histopathological examination. *Acanthosis nigricans* - Characterized by **dark, velvety, thickened patches** of skin, typically in body folds (neck, armpits, groin). - Usually **bilateral and symmetric**, not a solitary unilateral lesion. - Texture is velvety with papillomatous surface, different from the smooth surface implied here. - Not typically described as a progressively enlarging "lesion." *Basal cell carcinoma* - Most common skin cancer but typically presents as a **pearly or waxy nodule** with rolled borders and telangiectasias. - Predominantly occurs in **sun-exposed areas** (face, head, neck). - Pigmented BCC exists but is less common and usually shows characteristic rolled borders. - Inner thigh location is **atypical** for BCC. *Erythema nodosum* - Presents as **tender, painful, red nodules**, classically on the anterior shins. - An inflammatory condition, not a neoplastic process. - The lesion described is **painless** and **hyperpigmented**, which completely contradicts erythema nodosum. - Erythema nodosum lesions are acute/subacute, not slowly progressive over months.

Q: A 50-year-old male presents with multiple, waxy, brown, stuck-on lesions on his trunk. What is the most likely diagnosis?

Seborrheic keratosis. ***Seborrheic keratosis*** - This condition is characterized by **waxy**, **brown**, "stuck-on" lesions, perfectly matching the description. - They are common, **benign epidermal tumors** that typically appear in middle to older age on the trunk, face, or scalp. *Actinic keratosis* - These are **pre-malignant lesions** that are usually rough, scaly patches on sun-exposed skin. - They lack the "stuck-on" appearance and waxy texture described in the patient. *Melanoma* - Melanoma is a **malignant skin cancer** that typically presents as an asymmetrical, irregularly bordered, multi-colored lesion with a changing diameter. - While it can be dark, it usually doesn't have the waxy, "stuck-on" quality of seborrheic keratoses. *Basal cell carcinoma* - This is the most common form of **skin cancer**, often appearing as a pearly nodule with rolled borders, telangiectasias, or a non-healing sore. - It does not present with multiple, waxy, brown, "stuck-on" lesions as described.

Q: A 60-year-old male presents with a rough, scaly plaque on his forehead that has been slowly enlarging. What is the most likely diagnosis?

Actinic keratosis. ***Actinic keratosis*** - This presents as a **rough, scaly plaque** on sun-exposed areas like the forehead, which is characteristic of actinic keratosis. - Actinic keratoses are considered **premalignant lesions** with the potential to progress to squamous cell carcinoma. *Basal cell carcinoma* - Typically presents as a **pearly papule** with rolled borders and telangiectasias, or sometimes as an ulcerated lesion. - While it occurs on sun-exposed areas, the description of a **rough, scaly plaque** is less typical for classic basal cell carcinoma. *Melanoma* - Often presents with features associated with the **ABCDEs** (Asymmetry, Border irregularity, Color variability, Diameter >6mm, Evolving). - While it can be scaly, the primary concern for melanoma is its pigmentary changes and infiltrative growth, not just a rough plaque. *Seborrheic keratosis* - Characterized by a **"stuck-on" appearance**, often waxy or greasy, with well-demarcated borders and horn cysts (pseudohorn cysts). - While benign and common in older individuals, the description of a rough, scaly plaque is more indicative of a sun-damaged lesion rather than a seborrheic keratosis.

Question 1

Which procedure is most appropriate for a 0.8cm superficial BCC on the cheek?

Accepted Answer

Mohs surgery

Answer

Curettage and electrodesiccation

Answer

Cryotherapy

Answer

Excision with 4mm margins

Question 2

A 60-year-old man with history of multiple non-melanoma skin cancers presents with a 1.5cm pearly nodule with telangiectasia on the right nasal ala, extending to the alar crease. He's on warfarin for mechanical heart valve (INR 2.8) and has previously developed keloids after surgery. Recent biopsy shows infiltrative BCC. Most appropriate management is:

Accepted Answer

Mohs surgery while continuing anticoagulation

Answer

Radiation therapy

Answer

Hedgehog inhibitor therapy

Answer

Wide local excision under local anesthesia

Question 3

A patient consults a dermatologist about a skin lesion on her neck. Examination reveals a 1-cm diameter, red, scaly plaque with a rough texture and irregular margins. Biopsy demonstrates epidermal cells with large, pleomorphic, hyperchromatic nuclei. What is the most likely diagnosis?

Accepted Answer

Actinic keratosis

Answer

Dermal nevus

Answer

Junctional nevus

Answer

Compound nevus

Question 4

A child presents with linear verrucous plaques on the trunk, accompanied by vacuolization of keratinocytes in the stratum spinosum and stratum granulosum. What is the diagnosis?

Accepted Answer

Verrucous epidermal nevus

Answer

Incontinentia pigmenti

Answer

Delayed hypersensitivity reaction

Answer

Linear Darier's disease

Question 5

A 50-year-old man presents with a rapidly enlarging, painless nodule on his ear. A biopsy shows keratin pearls and atypical squamous cells. What is the diagnosis?

Accepted Answer

Squamous cell carcinoma

Answer

Basal cell carcinoma

Answer

Actinic keratosis

Answer

Keratoacanthoma

Question 6

A 70-year-old man presents with a rough, scaly lesion on his face that does not heal. A biopsy shows atypical keratinocytes. What is the diagnosis?

Accepted Answer

Actinic keratosis

Answer

Basal cell carcinoma

Answer

Squamous cell carcinoma

Answer

Seborrheic keratosis

Question 7

A 40-year-old man presents with multiple firm, pink nodules on his trunk. Histopathology reveals a storiform pattern with CD34 positivity. What is the most likely diagnosis?

Accepted Answer

Dermatofibrosarcoma protuberans

Answer

Keloid

Answer

Neurofibroma

Answer

Basal cell carcinoma

Question 8

A 34-year-old man presents with a painless, hyperpigmented lesion on the inner aspect of his right thigh that has increased in size over the last 6 months. What is the most likely diagnosis?

Accepted Answer

Malignant melanoma

Answer

Acanthosis nigricans

Answer

Basal cell carcinoma

Answer

Erythema nodosum

Question 9

A 50-year-old male presents with multiple, waxy, brown, stuck-on lesions on his trunk. What is the most likely diagnosis?

Accepted Answer

Seborrheic keratosis

Answer

Actinic keratosis

Answer

Melanoma

Answer

Basal cell carcinoma

Question 10

A 60-year-old male presents with a rough, scaly plaque on his forehead that has been slowly enlarging. What is the most likely diagnosis?

Accepted Answer

Actinic keratosis

Answer

Basal cell carcinoma

Answer

Melanoma

Answer

Seborrheic keratosis

Skin Tumors — MCQs

Skin Tumors — MCQs

On this page

Practice by Chapter

Want unlimited practice?