A lung cancer spread into a benign tumor in the abdominal wall

Benign tumors are rarely the target of cancer metastases, and schwannomas, which are benign nerve sheath tumors, are uncommon recipients. This case report describes a 60-year-old woman with lung squamous cell carcinoma who had received three cycles of chemoimmunotherapy before surgery.

Follow-up PET-CT showed an active lung lesion, metastatic lymph nodes, and fat stranding in the skin and subcutaneous tissue of the abdominal wall. She underwent thoracoscopy with pleural biopsies, and the abdominal wall lesion was excised. Pathology showed metastatic squamous cell carcinoma in the pleura. The abdominal wall lesion was a schwannoma containing foci of metastatic squamous cell carcinoma, confirmed by p40 staining.

The authors note that such cases pose diagnostic challenges and call for careful pathological evaluation. As a single case report, it cannot show how often this happens.