A 65-year-old man comes to the office due to 2 months of fatigue and persistent, nonproductive cough. He has a history of coronary artery disease and myocardial infarction. Three years ago, he underwent wide local excision of a melanoma on his posterior neck. The patient has a 50-pack-year smoking history. Vital signs are within normal limits. Chest radiograph reveals multiple lung lesions and hilar lymphadenopathy. Histopathology from one of the biopsied lung lesions is shown below after staining with hematoxylin and eosin. These histopathologic findings are most consistent with which of the following diagnoses?

Question

A 65-year-old man comes to the office due to 2 months of fatigue and persistent, nonproductive cough.  He has a history of coronary artery disease and myocardial infarction.  Three years ago, he underwent wide local excision of a melanoma on his posterior neck.  The patient has a 50-pack-year smoking history.  Vital signs are within normal limits.  Chest radiograph reveals multiple lung lesions and hilar lymphadenopathy.  Histopathology from one of the biopsied lung lesions is shown below after staining with hematoxylin and eosin.  These histopathologic findings are most consistent with which of the following diagnoses?

Quizplus · Accepted Answer

11ec160b_38fc_de20_9249_bdd751b26b8a_MD0001_00 Histopathology from this patient's lung lesion reveals features concerning for malignancy, including disordered, pleomorphic cells; large nuclei; irregular nuclear shape and binucleation; as well as prominent nucleoli. Although he is at risk for primary lung cancer due to a long smoking history, the presence of brown pigment (melanin granules) in the cytoplasm of some of the atypical cells indicates likely melanoma recurrence. Surgical resection of cutaneous melanoma is sometimes curative, but the tumor often spreads through the lymphatics and bloodstream to other organs early in the disease course; these metastases can remain asymptomatic for months to years. Recurrence is generally diagnosed when a suspicious lesion is identified and biopsy reveals malignant melanocytes (eg, cytoplasmic melanin, cellular atypia) with positive immunostaining for melanocytic markers (eg, S-100, HMB-45). (Choice A) Chronic systolic heart failure can sometimes be associated with cough and fatigue due to pulmonary congestion. Although brown, hemosiderin-laden macrophages can be seen, atypical cells (eg, binucleated, enlarged nuclei) and hilar lymphadenopathy would not be present. (Choice B) This patient is at risk for emphysema due to his long smoking history. Although emphysema often causes dyspnea and cough, biopsy would show airspace enlargement and destruction of alveolar walls. (Choice C) Hodgkin lymphoma frequently presents with diffuse lymphadenopathy or pulmonary symptoms (eg, cough) related to a mediastinal mass. However, biopsy would show malignant Reed-Sternberg cells amidst an inflammatory infiltrate (not cells with dark pigment). (Choice E) Sarcoidosis frequently causes pulmonary symptoms and fatigue and often presents with hilar lymphadenopathy and reticular pulmonary infiltrates. However, biopsy would show noncaseating granulomas, not pigmented, atypical cells. (Choice F) Squamous cell lung cancer frequently presents with cough and fatigue. Although atypical cells would be seen on biopsy, keratin (not brown pigment) would be present. Educational objective: Melanoma is a highly aggressive malignancy that often metastasizes early in the disease course. Patients may be asymptomatic for years prior to onset of metastatic manifestations. Diagnosis is generally made when a histopathologic sample shows cellular atypia with cells containing brown pigment (melanin granules); immunostaining for melanocytic markers (eg, S-100, HMB-45) is generally positive. __________ References: Decoding melanoma metastasis. (http://www.ncbi.nlm.nih.gov/pubmed/24212610)

A 65-Year-Old Man Comes to the Office Due to 2