Cutaneous Metastasis of a Pulmonary Carcinoid Tumor
Carcinoid tumors are uncommon neoplasms of neuroendocrine origin that generally arise in the gastrointestinal or bronchopulmonary tracts and typically are characterized by an indolent clinical course. Metastases from these primary neoplasms more commonly affect the viscera, with rare reports of cutaneous metastases to the skin. We report the case of a patient with a cutaneous carcinoid metastasis that was incidentally brought to our attention because of the exquisite tenderness of the lesion. A brief review of the literature also is provided.
Practice Points
- Cutaneous metastases of carcinoid tumors are extremely rare, and clinical presentation can vary. They can present as firm papules ranging in color from pink to brown, can be painful, and could occur at any site.
- It is imperative to obtain an accurate clinical history and use the appropriate immunohistochemical panel to correctly diagnose cutaneous metastases of carcinoid tumors.
- Neoplasms within the gastrointestinal tract commonly present with carcinoid syndrome, but it also has been observed with bronchial carcinoid tumors and with metastatic disease.
Case Report
A 72-year-old white man with a history of pancreatic adenocarcinoma presented for Mohs micrographic surgery of a basal cell carcinoma on the right helix. On the day of the surgery, the patient reported a new, rapidly growing, exquisitely painful lesion on the cheek of 3 to 4 weeks’ duration. Physical examination revealed a 0.8×0.8×0.8-cm, extremely tender, firm, pink papule on the right preauricular cheek. A horizontal deep shave excision was done and the histopathology was remarkable for neoplastic cells with necrosis in the dermis. We observed dermal cellular infiltrates in the form of sheets and nodules, some showing central necrosis (Figure 1). At higher magnification, a trabecular arrangement of cells was seen. These cells had a moderate amount of cytoplasm with eccentric nuclei and rare nucleoli (Figure 2). Mitotic figures were seen at higher magnification (Figure 3). Immunohistochemistry of the neoplastic cells exhibited similar positive staining for the neuroendocrine markers chromogranin A and synaptophysin (Figure 4). Staining of the neoplastic cells also was positive for thyroid transcription factor 1 (TTF-1) and cancer antigen 19-9. Villin and caudal type homeobox 2 stains were negative. These results were consistent with cutaneous metastasis from a known pulmonary carcinoid tumor.
On further review of the patient’s medical history, it was discovered that he had undergone a Whipple procedure with adjuvant chemotherapy and radiation for pancreatic adenocarcinoma approximately 4 years prior to the current presentation. He was then followed by oncology, and 3 years later a chest computed tomography suggested possible disease progression with a new pulmonary metastasis. This pulmonary lesion was biopsied and immunologic staining was consistent with a primary neuroendocrine neoplasm of the lung, a new carcinoid tumor. The tissue was positive for cytokeratin (CK) 7,TTF-1, cancer antigen 19-9, CD56, synaptophysin, and chromogranin A, and was negative for villin and CK20. By the time he was seen in our clinic, several trials of chemotherapy had failed. Serial computed tomography subsequently demonstrated progression of the lung disease and he later developed malignant pleural effusions. Approximately 6 months after the cutaneous carcinoid metastasis was diagnosed, the patient died of respiratory failure.
