A 69‐year‐old Japanese man visited our hospital because of worsening shortness of breath. His chest computed tomography (CT) showed a giant left lung mass with a massive left pleural effusion. He could not be treated with chemotherapy and eventually died from a rapidly progressive tumor. He was diagnosed with combined small cell lung carcinoma (C‐SCLC) with spindle‐shaped cell tumor at autopsy. C‐SCLC is characterized by pathologically concurrent SCLC and adenocarcinoma or squamous cell carcinoma, or rarely, spindle‐shaped cell tumor. The clinical course of C‐SCLC with spindle‐shaped cell tumor has not previously been determined. Our patient's tumor increased by 2.59‐fold in 20 days. The combination of C‐SCLC with spindle‐shaped cell tumor suggested rapid progression and a poor prognosis.
We present a rare case of C‐SCLC with three different components (SCLC, adenocarcinoma, and a spindle‐shaped cell tumor). Two thoracenteses did not allow for a diagnosis, but thoracoscopic pleural biopsy showed features of SCLC (a), adenocarcinoma (b), and a spindle‐shaped cell tumor (c). Autopsy led to a diagnosis of C‐SCLC including those three tumor components. Our patient's tumor increased by 2.59‐fold in size in 20 days, suggesting that the combination of C‐SCLC with a spindle‐shaped cell tumor caused rapid progression and a poor prognosis. Physicians should be aware of the proper diagnosis of C‐SCLC including spindle‐shaped cell tumors in patients with rapidly progressive lung cancer in addition to SCLC.