33 terms


For the past decade, a 29-year-old man has had waxing and waning of the lesions shown in the figure.(psoriasis, marked epithelial hyperplasia, parakeratotic scaling) The scalp, lumbosacral region, and glans penis also are affected. For the past 2 years, he has had chronic arthritis in the hips and knees. Which of the following physical findings would most likely be present in this patient?
□ (A) Guaiac-positive stool
□ (B) Friction rub
□ (C) Hyperreflexia
□ (D) Damage to the nails
□ (E) Hypertension
An epidemiologic study is conducted to identify factors that increase the risk of skin cancer. The study documents subjects reported to tumor registries with a diagnosis of malignant melanoma and the incidence of melanoma worldwide over the past 25 years. Demographic information is collected. Analysis of the data is most likely to show the greatest increase in incidence of malignant melanoma in which of the following locations?
□ (A) Edinburgh, Scotland
□ (B) Cairo, Egypt
□ (C) Brisbane, Australia
□ (D) Tahiti, French Polynesia
□ (E) Hong Kong, China
A 64-year-old man has noted changes in the texture and color of skin in his armpit and groin over the past 3 months. On physical examination, there is thickened, darkly pigmented skin in the axillae and flexural areas of the neck and groin. These areas are neither painful nor pruritic. A punch biopsy specimen of axillary skin shows undulating epidermal acanthosis with hyperkeratosis and basal layer hyperpigmentation. Which of the following underlying diseases is most
likely to be present in this patient?
□ (A) Systemic lupus erythematosus
□ (B) Mastocytosis
□ (C) AIDS
□ (D) Colonic adenocarcinoma
□ (E) Langerhans cell histiocytosis
A 51-year-old man noticed a change in the skin lesion on the upper, outer area of his right arm, shown in the figure. The lesion has enlarged during the past month. Physical examination yields no other remarkable findings.(malignant melaoma) Which of the following occupations is this man most likely to have had earlier in life?
□ (A) Chemist
□ (B) Lifeguard
□ (C) Miner
□ (D) Auto mechanic
□ (E) Radiation oncologist
A 35-year-old man has had an outbreak of pruritic lesions over the extensor surfaces of the elbows and knees during the past month. He has a history of malabsorption that requires him to eat a special diet, but he has had no previous skin problems. On physical examination, the lesions are 0.4- to 0.7-cm vesicles. A 3-mm punch biopsy of one of the lesions over the elbow is performed. Microscopic examination of the biopsy specimen shows accumulation of neutrophils at the
tips of dermal papillae and formation of small blisters owing to separation at the dermoepidermal junction.
Immunofluorescence studies performed on this specimen show granular deposits of IgA localized to tips of dermal papillae. Laboratory studies show serum antigliadin antibodies. What is the most likely diagnosis?
□ (A) Bullous pemphigoid
□ (B) Contact dermatitis
□ (C) Dermatitis herpetiformis
□ (D) Discoid lupus erythematosus
□ (E) Erythema multiforme
□ (F) Impetigo
□ (G) Lichen planus
□ (H) Pemphigus vulgaris
Over the course of 1 week, a 6-year-old boy develops 1- to 2-cm erythematous macules and 0.5- to 1-cm pustules on his face. During the next 2 days, some of the pustules break, forming shallow erosions covered by a honey-colored crust. New lesions form around the crust. The boy's 40-year-old uncle develops similar lesions after visiting for 1 week during the child's illness. Removal of the crusts from the boy's face is followed by healing within 1 week. The uncle does not seek medical care, and additional pustules form at the periphery of the crusts. Which of the following conditions most likely
explains these findings?
□ (A) Acne vulgaris
□ (B) Bullous pemphigoid
□ (C) Contact dermatitis
□ (D) Erythema multiforme
□ (E) Impetigo
A 50-year-old woman has been bothered by a discolored area of skin on her forehead that has not faded during the past 3 years. On physical examination, there is a 0.8-cm red, rough-surfaced lesion on the right forehead above the eyebrow. A biopsy specimen examined microscopically shows basal cell hyperplasia. Some of the basal cells show nuclear atypia associated with marked hyperkeratosis and parakeratosis with thinning of the epidermis. The upper dermal collagen and
elastic fibers show homogenization with elastosis. What is the most appropriate advice to give this patient?
□ (A) Reduce intake of dietary fat
□ (B) Wear a hat outdoors
□ (C) Stop taking aspirin for headaches
□ (D) Apply hydrocortisone cream to your face
□ (E) This condition is related to aging
A 10-year-old girl is brought to the physician by her mother because multiple excoriations have appeared on the skin of her hands over the past week. The child reports that she scratches her hands because they itch. Physical examination shows several 0.2- to 0.6-cm linear streaks in the interdigital regions. Treatment with a topical lindane lotion resolves the condition. Which of the following organisms is most likely responsible for these findings?
□ (A) Ixodes scapularis
□ (B) Tinea corporis
□ (C) Staphylococcus aureus
□ (D) Molluscum contagiosum
□ (E) Sarcoptes scabiei
A 35-year-old man has noted a bump on his upper trunk for the past 6 weeks. On physical examination, there is a solitary, 0.4-cm, flesh-colored nodule on the upper trunk. The dome-shaped lesion is umbilicated, and a curdlike material can be expressed from the center. This material is smeared on a slide, and Giemsa stain shows many pink, homogeneous, cytoplasmic inclusions. The lesion regresses over the next 2 months. Which of the following infectious agents most likely produced this lesion?
□ (A) Human papillomavirus
□ (B) Staphylococcus aureus
□ (C) Molluscum contagiosum
□ (D) Histoplasma capsulatum
□ (E) Varicella-zoster virus
Many skin disorders give rise to vesicles or bullae (blisters) in the skin. The location of the bulla often aids in the diagnosis. What disorder is most likely to produce the type of blister that is schematically illustrated in the figure?
□ (A) Impetigo
□ (B) Pemphigus vulgaris
□ (C) Bullous pemphigoid
□ (D) Acute eczematous dermatitis
□ (E) Urticaria
A 39-year-old woman has a nodule on her back that has become larger over the past 2 months. On physical examination, there is a 2.1-cm pigmented lesion with irregular borders and an irregular brown-to-black color. An excisional biopsy with wide margins is performed, and microscopic examination of the biopsy specimen shows a malignant melanoma composed of epithelioid cells that extends 2 mm down to the reticular dermis. There is a band of lymphocytes beneath the
melanoma. Which of the following statements is most appropriate to make to this patient regarding these findings?
□ (A) Your immune system will prevent metastases
□ (B) The prognosis is poor
□ (C) Other family members are at risk for this condition
□ (D) The primary site for this lesion is probably the eye
□ (E) Nevi elsewhere on your body may become malignant
A 39-year-old woman goes to her dentist for a routine checkup. The dentist notes that she has 0.2- to 1.5-cm scattered, white, reticulated areas on the buccal mucosa. The woman says that these lesions have been present for 1 year. She also has some 0.3-cm purple, pruritic papules on each elbow. A biopsy specimen of a skin lesion shows a bandlike infiltrate of lymphocytes at the dermal-epidermal junction and degeneration of basal keratinocytes. What is the best advice to give this patient regarding these lesions?
□ (A) A squamous cell carcinoma is likely to develop
□ (B) You may develop chronic renal disease
□ (C) A skin test for tuberculosis needs to be performed
□ (D) You should stop taking all medications
□ (E) These lesions will probably resolve over time
A 22-year-old man and other members of his racquetball club have noticed more itching of their feet in the past 2 months. On physical examination, the man has diffuse, erythematous, scaling skin lesions between the toes of both feet. There are no other remarkable findings. These findings are most likely the result of infection with which of the following organisms?
□ (A) Borrelia burgdorferi
□ (B) Group A β-hemolytic streptococcus
□ (C) Herpes simplex virus
□ (D) Varicella-zoster virus
□ (E) Human papillomavirus
□ (F) Molluscum contagiosum
□ (G) Propionibacterium acnes
□ (H) Sarcoptes scabiei
□ (I) Staphylococcus aureus
□ (J) Trichophyton rubrum
Over the past 20 years, a 75-year-old man has noticed slowly enlarging lesions, similar to those shown in the figure, on his trunk. One of the lesions is excised, and microscopic examination shows sheets of lightly pigmented basaloid cells that surround keratin-filled cysts. This lesion is sharply demarcated from the surrounding epidermis. What is the most likely
□ (A) Basal cell carcinoma
□ (B) Condyloma acuminatum
□ (C) Intradermal nevus
□ (D) Keratoacanthoma
□ (E) Melanoma
□ (F) Seborrheic keratosis
□ (G) Squamous cell carcinoma
□ (H) Verruca vulgaris
A 30-year-old man is known for his large appetite. At a luncheon meeting, he notices that all the cookies contain nuts, which the other diners have ordered knowing that he would not eat them because he would develop blotchy erythematous, slightly edematous, pruritic plaques on his skin. These plaques would form and then fade within 2 hours. If the man eats the cookies, which of the following sensitized cells would release a mediator that produces these skin lesions?
□ (A) Mast cell
□ (B) Neutrophil
□ (C) Natural killer cell
□ (D) CD4+ lymphocyte
□ (E) Plasma cells
A 17-year-old girl has hundreds of skin lesions on her body that have been forming since childhood. On physical examination, 0.4- to 1.7-cm, macular to slightly raised, plaquelike, dark brown pigmented lesions are present on sun-exposed and non-sun-exposed areas of skin. The lesions have irregular contours, and there is variability in pigmentation. She says that her 15-year-old brother has similar lesions. Which of the following molecular changes are most likely to be
present in the DNA from this patient?
□ (A) Deletion of the von Hippel-Lindau (VHL) gene
□ (B) Mutation of the PTCH gene
□ (C) Integration of the human papillomavirus-16 (HPV-16) genome
□ (D) Deletion of the p16/INK4A (CDNK2) gene
□ (E) Microsatellite instability
□ (F) Ultraviolet light-induced damage from pyrimidine dimers
A 60-year-old man has noted the appearance of a nodule on his ear during the past month. On physical examination,
there is a 1.2-cm, flesh-colored, dome-shaped nodule on his right ear lobe. The nodule has a central keratin-filled crater surrounded by proliferating epithelium. The lesion regresses and disappears within 1 month. What is the most appropriate diagnosis of this lesion?
□ (A) Squamous cell carcinoma
□ (B) Basal cell carcinoma
□ (C) Seborrheic keratosis
□ (D) Actinic keratosis
□ (E) Keratoacanthoma
□ (F) Verruca vulgaris
A 68-year-old man visits the physician because of a slowly enlarging nodule on his right eyelid. On physical examination, there is a 0.3-cm pearly nodule on the upper eyelid near the lateral limbus of the right eye. The lesion is excised, but multiple frozen sections are made during the surgery to minimize the extent of the resection and preserve the eyelid. The microscopic appearance of the lesion is shown at low magnification in the figure. What is the most likely
□ (A) Malignant melanoma
□ (B) Dermatofibroma
□ (C) Actinic keratosis
□ (D) Nevocellular nevus
□ (E) Basal cell carcinoma
A 5-year-old girl is brought to the physician by her parents for a routine health checkup. On physical examination, she
has scattered 1- to 3-mm, light brown macules on her face, trunk, and extremities. The parents state that these maculesbecome more numerous in the summer months, but fade over the winter. The lesions do not itch, bleed, or hurt. What is the most likely diagnosis?
□ (A) Vitiligo
□ (B) Lentigo
□ (C) Freckle
□ (D) Nevus
□ (E) Melasma
A 19-year-old man has facial and upper back lesions that have waxed and waned for the past 6 years. On physical
examination, there are 0.3- to 0.9-cm comedones, erythematous papules, nodules, and pustules most numerous on the lower face and posterior upper trunk. Other family members have been affected by this condition at a similar age. The lesions worsen during a 5-day cruise to the Caribbean. Which of the following organisms is most likely to play a key role in
the pathogenesis of these lesions?
□ (A) Staphylococcus aureus
□ (B) Herpes simplex virus type 1
□ (C) Group A β-hemolytic streptococcus
□ (D) Mycobacterium leprae
□ (E) Propionibacterium acnes
A 53-year-old man with idiopathic dilated cardiomyopathy underwent orthotopic heart transplantation. During the next 5 years, he had two episodes of minimal cellular rejection, which were adequately treated by an increase in immunosuppressive therapy. He has developed multiple skin lesions on the face and upper trunk over the past 6 months. On physical examination, the lesions are similar to the lesion shown in the figure. Some of the larger lesions have ulcerated. A biopsy specimen is most likely to identify which of the following lesions?
□ (A) Psoriasis
□ (B) Lichen planus
□ (C) Dermatofibroma
□ (D) Squamous cell carcinoma
□ (E) Erythema multiforme
A 39-year-old woman comes to her physician because she has developed vesicular skin lesions over the past week. On physical examination, she has multiple, 0.2- to 1-cm vesicles and bullae on the skin of her scalp, in both axillae, in the groin, and on the knees. Many lesions appear to have ruptured, and a shallow erosion with a dried crust of serum remains. A biopsy specimen of an axillary lesion examined microscopically shows epidermal acantholysis and formation of an intraepidermal blister. The basal cell layer is intact. Which of the following additional tests is most likely to explain the
pathogenesis of the patient's disease?
□ (A) Immunofluorescent staining of skin with anti-IgG
□ (B) Viral culture of fluid from a skin vesicle
□ (C) Determination of serum IgE level
□ (D) Cytokeratin immunohistochemical staining
□ (E) Dark-field microscopy of vesicular fluid
For the past 3 days, a 25-year-old man known to be infected with HIV has had increasing fever, cough, and dyspnea, which has culminated in acute respiratory failure. On admission to the hospital, his temperature is 37.8°C. On physical examination, there are no significant findings. He undergoes a bronchoalveolar lavage that yields Pneumocystis jiroveci by direct fluorescent antigen testing. Within 1 week after initiation of therapy, he develops "target lesions" composed of
red macules with a pale, vesicular center. The 2- to 5-cm lesions are distributed symmetrically over the upper arms and chest. Which of the following drugs is most likely to be implicated in the development of these lesions?
□ (A) Ritonavir
□ (B) Pentamidine
□ (C) Sulfamethoxazole
□ (D) Zidovudine
□ (E) Dapsone
□ (F) Adefovir
□ (G) Nevirapine
A 28-year-old man has noticed slowly enlarging lesions on his hands for the past 3 years. On physical examination, the lesions appear similar to those shown in the figure. There are no other remarkable findings. The lesions have not changed in color, do not itch or bleed, and are not associated with pain. What is the most likely diagnosis?
□ (A) Basal cell carcinoma
□ (B) Condyloma acuminatum
□ (C) Dermatofibroma
□ (D) Intradermal nevus
□ (E) Keratoacanthoma
□ (F) Molluscum contagiosum
□ (G) Seborrheic keratosis
□ (H) Squamous cell carcinoma
□ (I) Verruca vulgaris
A 32-year-old woman has noticed depigmented areas on her trunk that have waxed and waned for several months. She says that they do not itch or bleed, and are not painful. Physical examination shows variably sized, 0.3- to 1.2-cm macules over her upper trunk. The macules are lighter colored than the surrounding skin and have a fine, peripheral scale. Infection with which of the following organisms is most likely to produce these findings?
□ (A) Epidermophyton species
□ (B) Herpes simplex virus
□ (C) Human papillomavirus
□ (D) Malassezia furfur
□ (E) Molluscum contagiosum
□ (F) Mycobacterium leprae
□ (G) Propionibacterium acnes
□ (H) Sarcoptes scabiei
□ (I) Staphylococcus aureus
□ (J) Streptococcus pyogenes
After being hospitalized 1 week for treatment of an upper respiratory infection complicated by pneumonia, a 43-year-old woman develops a rash on her trunk and extremities. On physical examination, the 2- to 4-mm lesions are red, papulovesicular, oozing, and crusted. The lesions begin to disappear after she is discharged from the hospital 1 week later. What is the most likely pathogenesis of these lesions?
□ (A) Type I hypersensitivity
□ (B) Drug reaction
□ (C) Bacterial septicemia
□ (D) Photosensitivity
□ (E) Human papillomavirus infection
A 30-year-old man with a history of Crohn disease has noted the appearance of a painful red nodule on his left lower leg during the past week. On physical examination, his temperature is 37.3°C. There is a 0.4-cm, dark red nodule that is very tender to palpation and has a surrounding 5-cm diameter area of paler red skin. Over the next 3 weeks, this lesion resolves, but another develops on the opposite calf. A skin biopsy of the second lesion is done, and microscopic examination shows a dermal mixed inflammatory infiltrate with neutrophils, round cells, and giant cells with pronounced
edema. These lesions resolve without scarring, but more lesions develop during the next year. What is the most likely diagnosis?
□ (A) Acne vulgaris
□ (B) Dysplastic nevus
□ (C) Erythema nodosum
□ (D) Impetigo
□ (E) Keratoacanthoma
□ (F) Molluscum contagiosum
A 31-year-old man comes to his physician because of a bump on the skin of the lower abdomen that has enlarged over the past 4 years and has become more painful in the past week. On physical examination, there is a subcutaneous, movable, soft nodule at the belt line anteriorly that elicits pain with pressure. The overlying skin is intact. The patient states that the nodule began hurting about 1 day after he vigorously squeezed it. The lesion is excised and does not recur. Which of the following is the most likely diagnosis of this lesion?
□ (A) Acne vulgaris
□ (B) Epidermal inclusion cyst
□ (C) Fibroepithelial polyp
□ (D) Intradermal nevus
□ (E) Trichoepithelioma
□ (F) Xanthoma
A 9-year-old girl is brought to the physician by her parents because she has been scratching a group of small bumps
on the skin of her forearm for the past month. On physical examination, there are five 0.4- to 0.9-cm, small, flat to slightly papular, pale brown lesions on the volar surface. The lesions become more pruritic with swelling and erythema when rubbed. A biopsy specimen of one of the lesions examined microscopically shows an upper dermal infiltrate of large cellswith abundant pink cytoplasm that stains an intense purple color with toluidine blue. Which of the following cell types is most likely to form these lesions?
□ (A) CD4+ lymphocyte
□ (B) CD8+ lymphocyte
□ (C) Langerhans cell
□ (D) Macrophage
□ (E) Mast cell
□ (F) Melanocyte
□ (G) Merkel cell
A 50-year-old man notes several small, baglike lesions that have appeared on the skin in front of his armpits over the
past 2 years. On physical examination, five small, soft papules in the anterior axillary line are covered by wrinkled skin and attached to the skin surface by a thin pedicle. They are 0.5 to 0.8 cm in length and about 0.3 cm in diameter. One lesion has undergone torsion and is more erythematous and painful to touch than the others. What is the most likely diagnosis?
□ (A) Fibroepithelial polyp
□ (B) Hemangioma
□ (C) Lentigo
□ (D) Melasma
□ (E) Pilar cyst
□ (F) Xanthoma
A 10-year-old girl is brought to the physician by her parents because of an earache. On physical examination, the physician notices a flat, uniformly brown, 2-cm skin lesion, just above the right buttock. Her parents state that the lesion has been present since birth and has not changed in appearance. The figure shows the representative microscopic appearance of the lesion. What is the most likely diagnosis of this lesion?
□ (A) Acanthosis nigricans
□ (B) Basal cell carcinoma
□ (C) Dysplastic nevus
□ (D) Lentigo
□ (E) Malignant melanoma
□ (F) Nevocellular nevus
□ (G) Seborrheic keratosis
A 44-year-old woman has developed skin lesions over her elbows and knees during the past year. The lesions start as 4 mm pustules with surrounding erythema but then evolve into 1 to 5 cm plaques that are covered with a silvery-white scale. The lesions appear first in areas of local trauma, but exposure to sunlight causes the lesions to regress. A biopsy of one lesion shows thinning of stratum granulosum with marked overlying parakeratotic scale containing microabscesses.
Which of the following risk factors is most likely to be associated with her skin disease?
□ (A) Atopy
□ (B) Autoantibodies to desmoglein
□ (C) Exposure to plant allergens
□ (D) Germline HLA-C allele
□ (E) Herpes simplex virus infection
A 70-year-old man has a lesion on the right side of his face that has enlarged slowly over the past 5 years. On examination the 3 cm lesion has irregular borders and irregular brown to black pigmentation and a 2 mm raised blue-black nodule. The lesion is resected and microscopically shows radial growth of large round malignant cells singly and in nests in the epidermis and superficial papillary dermis. The cells have prominent red nucleoli and dust-like cytoplasmic pigment. Which of the following mutated genes is most likely to be present in the skin lesion of this man?
□ (A) ATM
□ (B) BRAF
□ (C) NF1
□ (D) TSC1
□ (E) XPA