Primary Pulmonary Paraganglioma: A Rare Clinical Entity

Paragangliomas are rare neuroendocrine tumors arising from extra-adrenal paraganglionic cells, with an estimated annual incidence of 2-8 cases per million. Primary pulmonary paragangliomas are exceptionally uncommon and are frequently mistaken for more prevalent pulmonary diseases, leading to diagnostic delays and management challenges. We report the case of a 60-year-old woman who presented with diffuse, non-radiating left-sided chest pain, progressive dyspnea transitioning from Modified Medical Research Council (mMRC) grades 0 to I, and unintentional weight loss over a two-year period. Laboratory investigations were unremarkable. Imaging demonstrated a well-defined mass in the left upper zone on chest radiograph, and contrast-enhanced computed tomography (CT) revealed a smoothly marginated, heterogeneously enhancing soft tissue lesion in the left upper lobe. Bronchoscopic biopsy initially suggested a clear cell neoplasm; however, immunohistochemical analysis demonstrated findings consistent with paraganglioma. The absence of clinical features suggestive of hereditary syndromes supported the diagnosis of a sporadic, non-functional pulmonary paraganglioma. This case underscores the importance of considering paraganglioma in the differential diagnosis of pulmonary masses and highlights the critical diagnostic role of immunohistochemistry in distinguishing this rare entity from morphologically similar tumors.