Dermatopathology Practice Questions

Question 1

A 52-year-old woman presents with erosions in her mouth that are persistent and painful. She says that symptoms appeared gradually 1 week ago and have progressively worsened. She also notes that, several days ago, flaccid blisters appeared on her skin, which almost immediately transformed to erosions as well. Which of the following is the most likely diagnosis?

Accepted Answer

Pemphigus vulgaris

Answer

Molluscum contagiosum

Answer

Psoriasis

Answer

Bullous pemphigoid

Answer

Staphylococcal infection (scalded skin syndrome)

Question 2

A 52-year-old Caucasian man presents to the clinic for evaluation of a mole on his back that he finds concerning. He states that his wife noticed the lesion and believes that it has been getting larger. On inspection, the lesion is 10 mm in diameter with irregular borders. A biopsy is performed. Pathology reveals abnormal melanocytes forming nests at the dermo-epidermal junction and discohesive cell growth into the epidermis. What is the most likely diagnosis?

Accepted Answer

Superficial spreading melanoma

Answer

Desmoplastic melanoma

Answer

Lentigo maligna melanoma

Answer

Nodular melanoma

Answer

Acral lentiginous melanoma

Question 3

A 47-year-old woman comes to her primary care doctor because of a new, pruritic rash. She was gardening in her yard two days ago and now has an eczematous papulovesicular rash on both ankles. You also note a single, 5 mm brown lesion with a slightly raised border on her left thigh. You prescribe a topical corticosteroid for contact dermatitis. Which of the following is the appropriate next step for the thigh lesion?

Accepted Answer

Further questioning

Answer

Full thickness biopsy

Answer

Simple shave biopsy

Answer

Reassurance

Answer

Topical corticosteroid

Question 4

A 34-year-old man presents to his dermatologist with white scaly papules and plaques on his extensor arms, elbows, knees, and shins. Scaly and flaky eruptions are also present on his ears, eyebrows, and scalp. He describes the lesions as being itchy and irritating. When the scales are scraped away, pinpoint bleeding is noted. His vital signs are unremarkable, and physical examination is otherwise within normal limits. Which of the following is the best initial test for this patient’s condition?

Accepted Answer

No tests are necessary

Answer

Serum autoantibodies

Answer

Plain film X-rays of the hands and feet

Answer

Skin biopsy

Answer

Wood’s lamp

Question 5

An investigator studying the molecular characteristics of various malignant cell lines collects tissue samples from several families with a known mutation in the TP53 tumor suppressor gene. Immunohistochemical testing performed on one of the cell samples stains positive for desmin. This sample was most likely obtained from which of the following neoplasms?

Accepted Answer

Rhabdomyosarcoma

Answer

Squamous cell carcinoma

Answer

Prostate cancer

Answer

Endometrial carcinoma

Answer

Melanoma

Question 6

A 29-year-old woman presents with skin lesions on her elbows and forearms. She notes that they first started appearing 2 months ago and have not improved. She describes the lesions as painless and rarely itchy. She denies any similar symptoms in the past, and has no other significant past medical history. Review of systems is significant for recent joint pain, conjunctivitis, and corneal dryness. The patient is afebrile and vital signs are within normal limits. Non-tender, raised, inflamed, white-silver maculopapular lesions are present. Which of the following are the most likely histopathologic findings in this patient's skin biopsy?

Accepted Answer

Acanthosis, hyperkeratosis with parakeratosis, and dermal papillary capillary proliferation

Answer

Intercellular edema with detachment at basal level

Answer

Cytoplasmic vacuolation

Answer

Nuclear atypia, cellular pleomorphism, and a disorganized structure of cells from basal to apical layers of the tissue

Answer

Subepidermal blister with detachment at dermal-epidermal junction

Question 7

A 59-year-old man comes to the physician for evaluation of a progressively enlarging, 8-mm skin lesion on the right shoulder that developed 1 month ago. The patient has a light-skinned complexion and has had several dysplastic nevi removed in the past. A photograph of the lesion is shown. The lesion is most likely derived from cells that are also the embryological origin of which of the following tumors?

Accepted Answer

Neuroblastoma

Answer

Adrenal adenoma

Answer

Liposarcoma

Answer

Basal cell carcinoma

Answer

Medullary thyroid cancer

Question 8

A 34-year-old man presents to the office for evaluation of a lesion on his upper arm that appeared a few months ago and has not healed. The patient appears healthful but has a history of cardiovascular disease. He states that his friend at the industrial ammunition factory where he works told him he should "get it looked at." The patient admits to some nausea, vomiting, and diarrhea over the past year, but he states that he "feels fine now." On physical examination, the lesion is an erythematous, scaly, ulcerated plaque on the flexor surface of his upper arm. The rest of the exam is within normal limits. What is the most likely diagnosis?

Accepted Answer

Squamous cell carcinoma (SCC)

Answer

Erythema multiforme

Answer

Actinic keratosis

Answer

Erysipelas

Answer

Contact dermatitis

Question 9

A 63-year-old man comes to the physician because of increasing generalized fatigue for 3 months. He is having more difficulty with keeping up with his activities of daily living and has lost 2.5 kg (5.5 lb) over the past month. He has hypertension and hyperlipidemia. He does not smoke and drinks two to three beers on weekends. His medications include lisinopril, hydrochlorothiazide, and atorvastatin. His temperature is 37.1°C (98.8°F), pulse is 85/min, respirations are 15/min, and blood pressure is 125/73 mm Hg. Examination shows pale conjunctivae. The remainder of the examination shows no abnormalities. His hematocrit is 27.3%, leukocyte count is 4500/mm3, and platelet count is 102,000/mm3. A peripheral blood smear shows numerous blast cells that stain positive for myeloperoxidase, CD33, and CD34. Which of the following is the most likely diagnosis?

Accepted Answer

Acute myeloid leukemia

Answer

Non-Hodgkin lymphoma

Answer

Hairy cell leukemia

Answer

Chronic lymphocytic leukemia

Answer

Acute lymphoblastic leukemia

Question 10

A 72-year-old nursing home resident is complaining of pruritis. She is noted to have multiple, tense blisters on her trunk as well as the flexor surfaces of her extremities. The blisters have an erythematous base. You are unable to extend the blisters when you apply lateral traction. You suspect an autoimmune bullous dermatosis. Which of the following is the cause of the likely condition?

Accepted Answer

Antibodies to hemidesmosomes

Answer

Antibodies to epidermal transglutaminase

Answer

Epidermal necrolysis

Answer

Antibodies to desmoglein

Answer

Antibodies to desmosomes

Dermatopathology

Study Resources

Lessons

Questions

Flashcards

Lessons

Inflammatory dermatoses

Vesiculobullous diseases

Infectious skin diseases

Benign epithelial tumors

Premalignant skin lesions

Non-melanoma skin cancers

Melanocytic nevi

Melanoma pathology

Adnexal tumors

Dermal tumors and proliferations

Panniculitis

Vascular disorders of skin

Disorders of pigmentation

Practice Questions

Flashcards

About Dermatopathology for USMLE

Lessons in Dermatopathology

Master Dermatopathology