[Glomus tumour of the lung: a case report and literature review].

BACKGROUND Glomus tumours are neoplasms arising from cells of the neuromyoarterial glomus bodies, which almost always occur in a subungual location. A lung location is extremely rare, with few cases reported in the literature. CLINICAL CASE The case is presented of a 33 year-old male, with non-productive cough, dyspnoea at rest, intermittent fever, and mild pain in rib cage. A chest radiograph showed a consolidation in the left lung, and computed tomography revealed a lesion in the hilum that extended to the bronchus of the lingula obstructing, and causing post-obstructive pneumonia. A biopsy was obtained by rigid bronchoscopy biopsy, which showed a well circumscribed tumour constituted by intermediate-sized cells, and abundant cytoplasm that are arranged in a pattern surrounding numerous thin-walled blood vessels, with no pleomorphism, significant mitotic activity or necrosis. Immunohistochemistry revealed diffuse positivity with smooth muscle actin, vimentin, caldesmon; focal reactivity with desmin and CD117, CD34 highlights the vascular pattern. Ki67 proliferation rate was 1%. Synaptophysin, EMA and cytokeratin cocktail were negative, making the diagnosis of glomus tumour. CONCLUSIONS Glomus tumours are rare neoplasms that usually appear in the dermis and subcutaneous tissue, where it is common to find glomus bodies. Occasionally glomus tumours can occur in extra-cutaneous sites such as the gastrointestinal tract, bone and respiratory system, with this case being a new case of rare lung location.