Pulmonary Atypical Carcinoid Tumor Presenting with Bilateral Ovarian and Cutaneous Metastases: A Rare Case Report

Abstract

Background: Pulmonary carcinoid tumors are rare, well-differentiated neuroendocrine neoplasms accounting for approximately 1–2% of all primary lung malignancies. Although pulmonary carcinoids generally exhibit an indolent clinical course, atypical carcinoids may show more aggressive behavior with an increased risk of lymph node involvement and distant metastases. Cutaneous and ovarian metastases from pulmonary carcinoid tumors are exceedingly uncommon. Case Presentation: A 49-year-old woman with no significant medical history presented with pelvic pain, progressive abdominal distension, and multiple subcutaneous nodules. Imaging revealed bilateral ovarian masses, thoraco- abdominal subcutaneous lesions, a right pulmonary nodule, mediastinal lymphadenopathy, and ascites. Histopathological examination of the ovarian specimen demonstrated a well-differentiated neuroendocrine tumor arranged in nests and solid sheets, with focal necrosis and a mitotic count of six mitoses per 10 high-power fields. Immunohistochemical analysis showed diffuse positivity for chromogranin A, synaptophysin, CD56, CK7, and thyroid transcription factor-1 (TTF-1), whereas CK20, WT1, PAX8, and GATA3 were negative, supporting a pulmonary primary origin. Biopsy of a presternal subcutaneous nodule revealed identical morphological and immunohistochemical features, confirming metastatic pulmonary atypical carcinoid involving the skin and both ovaries. Despite treatment with long- acting somatostatin analogs, disease progression occurred. Cisplatin- etoposide chemotherapy was subsequently initiated, resulting in significant clinical and radiological improvement after six cycles. Conclusion: Cutaneous and bilateral ovarian metastases from pulmonary atypical carcinoid tumors are exceedingly uncommon and may represent the initial manifestation of an occult primary lung tumor. This case emphasizes the importance of integrating imaging, histopathology, and immunohistochemistry to establish the correct diagnosis and guide appropriate therapeutic management.