Giant spindle cell rhabdomyosarcoma in an adult thorax: A case report.

Spindle cell rhabdomyosarcoma (SCRM), a rare and distinct subtype of RM, predominantly affects children. While SCRM can manifest in the head and neck regions of adults, primary occurrences in the thorax are exceedingly uncommon. In the present study, a 24-year-old female patient was admitted to the Affiliated Hospital of Zunyi Medical University (Zunyi, China) with a 10-month history of dull pain in the right side of the chest. The patient had previously received treatment for right-sided tuberculous pleurisy at another hospital for 6 months, but the symptoms persisted, and the chest pain progressively worsened. A chest computed tomography scan now revealed a large mass in the right thorax. Pathological examination following surgical resection confirmed a diagnosis of SCRM. The patient did not undergo standardized postoperative chemoradiotherapy and the 5-year follow-up examination indicated tumor recurrence. Primary thoracic SCRM is a rare tumor that morphologically resembles other spindle cell tumors. Immunohistochemistry is crucial for an accurate diagnosis, and surgical resection remains the primary treatment approach. The clinicopathological features, molecular genetic characteristics and biological behavior of SCRM are largely unknown due to its rarity. Consequently, large-sample studies are essential to enhance the understanding of this tumor and advance precision medicine treatments.