A 48-year-old man comes to the office for a routine medical evaluation and is found to have a skin lesion on his upper back. The patient is unsure when the lesion appeared but first noticed it several weeks ago during a shower. It is not painful, and he has no other symptoms. He has no chronic medical conditions and takes no medications. The patient drinks 1 or 2 beers nightly and does not use tobacco or illicit drugs. He works as a surfing instructor. Vital signs are within normal limits. Skin examination findings are shown in the exhibit. The remainder of the examination is normal. Which of the following is the most likely diagnosis?

Question

A 48-year-old man comes to the office for a routine medical evaluation and is found to have a skin lesion on his upper back.  The patient is unsure when the lesion appeared but first noticed it several weeks ago during a shower.  It is not painful, and he has no other symptoms.  He has no chronic medical conditions and takes no medications.  The patient drinks 1 or 2 beers nightly and does not use tobacco or illicit drugs.  He works as a surfing instructor.  Vital signs are within normal limits.  Skin examination findings are shown in the exhibit.  The remainder of the examination is normal.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Explanation: This patient developed a nodular, hyperpigmented lesion on an area of skin that likely gets excessive sun exposure while he surfs, raising strong suspicion for nodular malignant melanoma. In contrast to superficial spreading melanoma, which grows horizontally along the dermal layer, nodular melanoma grows vertically. Therefore, it often presents with few of the classic ABCDE criteria. Most cases are marked by a darkly pigmented lesion with uniform color and symmetric borders; however, suspicion is generally raised due to the presence of ?1 of the following features: ABCDE criteria The "ugly duckling sign" - patients with several pigmented cutaneous lesions (nevi) usually have lesions that all appear somewhat similar. When a single lesion looks significantly different from the others this is called the "ugly duckling sign"; it has a high sensitivity (up to 90%) for melanoma. Elevation from surrounding skin (eg, nodular, pedunculated) Firm to palpation Continuous growth over a month The diagnosis is generally confirmed by full-thickness excisional biopsy. (Choices A and C) Dermal angiosarcoma is a rare disorder that most commonly occurs in patients with prior radiation therapy. Cherry hemangioma is a common, benign lesion composed of congested capillaries and postcapillary venules in the papillary dermis. These disorders are usually heavily vascular (eg, bright red). angiosarcoma Cherry hemangioma (Choice B) Basal cell carcinoma is a common skin malignancy that typically appears as an enlarging fleshy nodule with ulceration. It is associated with sun exposure and is most common on the face, neck, and extremities. nodule (Choice D) Keratoacanthomas are nonpigmented cutaneous tumors that usually present as dome-shaped nodules with a central keratinous plug. Keratoacanthomas (Choice F) Seborrheic keratosis is a benign pigmented lesion with a well-demarcated border and a velvety or greasy surface. It can be nearly flat, but thickened lesions are often described as having a "stuck-on" appearance. Seborrheic keratosis Educational objective: The ABCDE criteria can assist in evaluation of superficial spreading melanoma but are less sensitive for other types of melanoma (eg, nodular, atypical). Nodular melanomas, the second most common type of melanoma, usually grow vertically and have symmetric borders and a uniform, dark color. Suspicion should be raised when the lesion appears different from other lesions on the patient ("ugly duckling sign") or the lesion grows continuously, is elevated, or is firm. References: Melanomas. (http://www.ncbi.nlm.nih.gov/pubmed/27692447) Cutaneous malignant melanoma: a primary care perspective. (http://www.ncbi.nlm.nih.gov/pubmed/22335216)

A 48-Year-Old Man Comes to the Office for a Routine