KMU Past Paper Practice

Question:

A 66-year-old outdoor worker has several rough erythematous lesions on the scalp. One lesion has become thicker than the others but remains superficial without a palpable dermal mass. The clinician wants to determine whether the lesion represents a premalignant keratinocytic change or a more advanced epithelial lesion. Which investigation is most useful for establishing this distinction?

Options:

Correct Answer: Histopathological examination of the lesion

Explanation: Histopathology demonstrates the degree and distribution of keratinocyte atypia and whether invasion is present, making it the definitive method for distinguishing premalignant, in situ and invasive epithelial lesions.

Question:

A 71-year-old man presents with a solitary persistent erythematous plaque on the trunk. It is sharply demarcated, scaly and has enlarged slowly. There is no palpable deep induration. Which diagnosis best fits the clinical pattern before biopsy?

Options:

Correct Answer: Bowen disease

Explanation: Bowen disease commonly presents as a persistent, well-defined erythematous scaly plaque. Lack of a palpable invasive component supports an intraepidermal process clinically.

Question:

A 69-year-old man with prolonged occupational sun exposure has a rough lesion on the helix of the ear. The lesion is small, erythematous and feels gritty on palpation. Which interpretation is most appropriate at this stage?

Options:

Correct Answer: Premalignant keratinocytic lesion related to cumulative ultraviolet injury

Explanation: A small gritty lesion on chronically sun-exposed skin strongly suggests actinic keratosis, representing UV-induced dysplastic proliferation of epidermal keratinocytes.

Question:

A 75-year-old woman has a slowly enlarging lesion beside the nose. Examination reveals a smooth translucent papule with a raised edge and central surface breakdown. A second lesion on her hand is rough, firm and keratotic. Which clinical feature of the facial lesion most strongly favors a different keratinocyte carcinoma from the hand lesion?

Options:

Correct Answer: Translucent raised edge with fine superficial vessels

Explanation: A translucent or pearly raised border with telangiectatic vessels strongly favors basal cell carcinoma, whereas a rough keratotic lesion is more suggestive of squamous differentiation.

Question:

A 32-year-old woman has numerous acquired pigmented lesions. Most are small, symmetric and uniformly brown. One lesion is larger, has a hazy irregular margin and shows several shades of brown with a slightly raised center. Which feature most strongly justifies further assessment of this particular lesion?

Options:

Correct Answer: Architectural irregularity compared with surrounding nevi

Explanation: A nevus that is larger, less symmetric, irregularly bordered and variably pigmented compared with the patient’s other nevi is clinically atypical and requires careful assessment.

Question:

A dermatologist examines a 27-year-old man with an atypical pigmented lesion. Dermoscopy shows irregular pigment structures, but the clinician cannot confidently distinguish a dysplastic nevus from an early melanoma. What is the principal role of dermoscopy in this situation?

Options:

Correct Answer: It improves clinical visualization and helps identify suspicious pigment patterns

Explanation: Dermoscopy enhances assessment of pigment and structural patterns and helps select suspicious lesions for biopsy; it does not replace histopathology when melanoma remains a concern.

Question:

A 10-year-old girl has a sharply circumscribed pink papule on the cheek. Because the lesion has enlarged, it is removed. Histological interpretation requires care because the melanocytic cells appear unusually large despite an overall benign pattern. Which clinical fact most strongly supports a benign Spitz nevus in this setting?

Options:

Correct Answer: Young age with a solitary pink papular lesion

Explanation: Spitz nevus classically occurs in children or young people as a solitary pink, red-brown or pigmented papule and may resemble melanoma histologically.

Question:

A 45-year-old man notices a new irregularly pigmented lesion on his upper back. His wife reports that it has become noticeably different from his other moles during the last few months. Which feature in this history carries the greatest diagnostic concern for melanoma?

Options:

Correct Answer: Progressive change relative to the patient’s other nevi

Explanation: Evolution and a lesion becoming distinctly different from surrounding nevi are important warning signs of melanoma and carry more diagnostic weight than location or pigmentation alone.

Question:

A 54-year-old woman is assessed for a newly suspicious pigmented lesion on the calf. During examination, the clinician recalls that melanoma shows characteristic site patterns that differ between sexes. Which site is particularly important in women?

Options:

Correct Answer: Lower limb

Explanation: The lower extremities are an important frequent site of melanoma in women, whereas the trunk, particularly the back, is an important site in men.

Question:

A 36-year-old patient has a clinically atypical nevus removed because it differs from surrounding lesions. Histology shows irregular melanocytic nests at the dermoepidermal junction together with stromal fibroplasia and a superficial inflammatory infiltrate. Which interpretation best integrates these findings?

Options:

Correct Answer: A dysplastic melanocytic nevus with architectural disorder

Explanation: Irregular junctional melanocytic nests, architectural disorder, fibroplasia and superficial inflammation are compatible with dysplastic nevus morphology rather than a keratinocyte carcinoma.

Question:

A 72-year-old man has a slowly enlarging ulcerated lesion on the temple. Biopsy shows nests of basaloid cells in the dermis. The clinician explains that the tumor may become locally destructive if neglected. Which additional pathological feature would best support the diagnosis?

Options:

Correct Answer: Cleft formation between tumor nests and stroma

Explanation: Basal cell carcinoma commonly shows stromal retraction, creating cleft-like spaces around basaloid tumor nests; this supports the diagnosis together with peripheral palisading.

Question:

A 63-year-old man has a firm ulcerated lesion on the lower lip. Microscopy shows malignant epithelial cells invading the dermis with preserved squamous differentiation. Which finding would most strongly indicate that the tumor is well differentiated?

Options:

Correct Answer: Concentric keratin formation within malignant nests

Explanation: Well-differentiated squamous cell carcinoma retains keratin-producing capacity, producing keratin pearls within nests of malignant squamous cells.

Question:

A 38-year-old woman has a pigmented lesion that has been present since early life and is considerably larger than her other nevi. She asks why this lesion is monitored more carefully than a small stable acquired nevus. Which explanation is most appropriate?

Options:

Correct Answer: It is associated with a greater melanoma risk when large

Explanation: Larger congenital melanocytic nevi are clinically important because they carry greater melanoma risk than ordinary small acquired nevi.

Question:

A 19-year-old student is found to have a small blue-black papule on the dorsal hand. It is symmetric and has remained unchanged for several years. Which feature most strongly supports a benign blue nevus rather than melanoma?

Options:

Correct Answer: Persistent stability with a regular outline

Explanation: A blue nevus is typically a small, symmetric, stable blue or blue-black lesion; progressive change, asymmetry or ulceration would increase concern for melanoma.

Question:

A 21-year-old man has a brown nevus surrounded by a sharply defined pale ring. The central lesion is otherwise symmetric and stable. Which interpretation best accounts for the surrounding change?

Options:

Correct Answer: Immune response directed against melanocytic cells

Explanation: The depigmented ring of a halo nevus results from an immune response against melanocytes and nevus cells, sometimes followed by regression of the central nevus.

Question:

A 47-year-old woman has a pigmented lesion on the thigh with irregular borders and several colors. Histology shows atypical melanocytes spreading horizontally along the dermoepidermal junction with little deep invasion. Which stage of melanoma growth is being demonstrated?

Options:

Correct Answer: Radial growth phase

Explanation: Radial growth describes predominantly horizontal proliferation of melanoma cells within the epidermis and superficial skin before development of a substantial deeper invasive component.

Question:

A suspicious pigmented lesion is biopsied. The pathologist identifies atypical melanocytes not only at the dermoepidermal junction but also scattered upward through higher layers of the epidermis. Which interpretation is most appropriate?

Options:

Correct Answer: Pagetoid spread supporting malignant melanoma

Explanation: Upward migration of atypical melanocytes through the epidermis is pagetoid spread, an important microscopic feature supporting melanoma.

Question:

A dermatologist evaluates two suspicious lesions. One is a pearly facial papule with superficial vessels, while the other is a firm keratotic plaque on the forearm. Histology of the second lesion is expected to show which feature rather than the characteristic pattern of the first?

Options:

Correct Answer: Malignant squamous cells with intercellular bridges

Explanation: The keratotic plaque favors squamous cell carcinoma, in which intercellular bridges and keratinization reflect squamous differentiation rather than the basaloid morphology of BCC.

Question:

A 50-year-old man presents with an irregularly pigmented lesion on the sole that has changed during the previous months. He assumed melanoma occurs only on highly sun-exposed skin. Which interpretation is most appropriate?

Options:

Correct Answer: Acral sites can be important locations for melanoma

Explanation: Melanoma may occur on palms, soles and subungual regions; therefore a changing acral pigmented lesion requires the same careful assessment as melanoma at other sites.

Question:

A 42-year-old woman with several atypical nevi asks how a clinician decides which lesion deserves the greatest attention during follow-up. Which finding provides the strongest reason to investigate a particular nevus further?

Options:

Correct Answer: A lesion showing new change in shape and pigmentation

Explanation: Evolution is one of the most important warning features in melanocytic lesions; a nevus developing new changes in shape or pigmentation warrants further evaluation for melanoma.