THE CASE
A 56-year-old woman with a history of melanoma in situ presented with progressive dyspnea on exertion, cough productive of clear sputum, and right-sided rib pain radiating to the upper back of 5 weeks’ duration.
Twenty-four years earlier, the patient had undergone excision of a skin lesion from the right side of her back. Pathology revealed melanoma in situ with no evidence of invasion of the underlying dermis. Because of close margins, she underwent wider excision 2 weeks later and no residual tumor was found. The patient subsequently underwent routine biannual dermatologic follow-up and transitioned (within the past few years) to annual dermatologic follow-up. At a recent dermatologic visit (9 months earlier), there were no suspicious skin lesions.
At current presentation, she denied fever, chills, night sweats, or unintentional weight loss. On examination, her vital signs were normal. Her pulse oximetry on room air was 95% at rest and 94% with ambulation. She had decreased breath sounds at the right lung base and a fixed 2 × 2-cm nontender, indurated mass in the right upper anterior chest wall, superior to the right breast. A skin examination was not performed at this time.
A complete blood count revealed a white blood cell count of 8220/mcL (reference range, 4500–11,000/mcL), hemoglobin of 13.6 g/dL (reference range, 14–17.5 g/dL), and a platelet count of 162 × 103/mcL (reference range, 150–350 × 103/mcL). The patient’s electrolytes were within normal limits, with a creatinine level of 0.67 mg/dL (reference range, 0.1–1.2 mg/dL) and a calcium level of 9.4 mg/dL (reference range, 8.2–10.2 mg/dL). Lactate dehydrogenase was elevated at 308 U/L (reference range, 100–200 U/L).
A chest radiograph revealed a right upper lobe mass, right lower lobe consolidation, and a large right-sided pleural effusion (FIGURE 1). Chest computed tomography (CT) with intravenous contrast revealed a 5.2 × 5.7–cm right pleural-based mass with extension to the anterior chest wall, 3 left-sided pulmonary nodules, numerous right-sided pleural-based nodules (FIGURE 2), and multiple low-density liver lesions. An abdominal and pelvic CT scan revealed a 5.6 × 2.5 × 4.8–cm hepatic lesion (FIGURE 3) with scattered hepatic cysts.
THE DIAGNOSIS
A diagnostic thoracentesis was performed, and pleural fluid cytology results revealed metastatic melanoma. Magnetic resonance imaging (MRI) of the brain showed no evidence of metastases.
After the patient’s initial presentation, her dermatologist performed a biopsy on a pre-existing skin lesion on the patient’s left abdomen, which initially was thought to be a cherry angioma. This left abdominal skin lesion was in a location different from her previous melanoma in situ, which was located on the right side of the back. Biopsy results of the presumed cherry angioma revealed a nodular malignant melanoma (which was partially removed), adjacent to a cherry angioma (which was completely excised).
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