Pulmonary Spindle Cell Carcinoma Mimicking Granulomatous Inflammation: A Rare Case Report and Brief Review of the Literature.

Background: Pulmonary spindle cell carcinoma (PSCC), a highly malignant tumor, often exhibits cell pleomorphism, a histopathological characteristic. Owing to its extremely low incidence, atypical imaging and clinical presentations, and insufficient awareness among clinicians, PSCC is often misdiagnosed, which results in delays in treatment. Herein, we reported a rare case of PSCC that was initially misdiagnosed as granulomatous inflammation.

Case presentation: A 66-year-old male visited a local hospital with symptoms such as cough and hemoptysis. A computed tomography (CT) scan of the chest revealed a mass in his right lung, and no mediastinal lymphadenopathy was observed. Bronchoscopy showed no major abnormalities, and the results of fine needle aspiration biopsy showed granulomatous inflammation. Even though the patient received anti-infection treatment, his symptoms did not improve markedly. After two months, a follow-up CT scan of the lung showed a noticeably enlarged mass accompanied by multiple instances of mediastinal lymphadenopathy in the upper lobe of the right lung. Consequently, he underwent a second CT-guided lung biopsy at our hospital. The pathology report indicated PSCC. Due to financial constraints, genetic testing was not performed. Given his poor overall physical condition, the patient was unable to undergo systemic chemotherapy and instead received palliative radiotherapy. The prescribed radiotherapy dose for the right upper lobe lung cancer and multiple metastatic lymph nodes was 60 Gy, administered in 30 fractions. Unfortunately, he failed to adhere to scheduled follow-ups and succumbed to the disease 6 months later, as confirmed during a telephone follow-up.

Conclusion: PSCC is a rare but highly malignant lung cancer. Multiple pathological biopsies are necessary to accurately and promptly diagnose the disease, which is crucial for early treatment intervention as well as improving patient prognosis.