Skin Cancer Pathology and Oncology Flashcards

Merkel cell carcinoma is a neuroendocrine tumor associated with which viral pathogen?

Answer: Merkel cell polyomavirus (MCPyV)

Merkel cell polyomavirus DNA is integrated in approximately 80% of Merkel cell carcinomas, and viral oncoproteins (T antigens) contribute to tumorigenesis by inactivating tumor suppressors.

What histological hallmark differentiates Bowen disease (SCC in situ) from invasive SCC?

Answer: Full-thickness epidermal dysplasia without invasion through the basement membrane

Bowen disease shows full-thickness dysplasia of the epidermis with preserved basement membrane — by definition, carcinoma in situ has not breached the basement membrane to invade the dermis.

Kaposi sarcoma is associated with which herpesvirus, and which patient population is classically affected in epidemic KS?

Answer: HHV-8 (KSHV); patients with advanced HIV/AIDS

Human herpesvirus 8 (Kaposi sarcoma-associated herpesvirus) causes all forms of KS; epidemic KS affecting HIV-positive patients with AIDS was the most prevalent form during the AIDS epidemic.

Extramammary Paget disease most commonly affects which anatomical sites?

Answer: Vulva, perianal region, and scrotum

Extramammary Paget disease presents as erythematous, eczematous plaques with large clear (Paget) cells and may be associated with an underlying adnexal or visceral adenocarcinoma.

Which of the following is a high-risk feature of SCC that significantly increases metastatic potential?

Answer: Tumor diameter >2 cm, depth >2 mm, perineural invasion, or immunosuppression

High-risk SCC features include large size (>2 cm), deep invasion (>2 mm), poor differentiation, perineural or lymphovascular invasion, location on ear/lip, and patient immunosuppression.

What is the most common site of origin for lentigo maligna melanoma?

Answer: Sun-damaged skin of the head and neck in elderly patients

Lentigo maligna melanoma develops from lentigo maligna (melanoma in situ) on chronically sun-damaged skin, most commonly on the face of elderly individuals.