title: Malignant transformation in a thymic cyst.
abstract: Thymic cysts have not been previously reported to show malignant transformation. This is the first documented case of well-differentiated papillary squamous cell carcinoma arising in a preexisting thymic cyst. The tumor was treated by surgical excision with no evidence of metastasis 6 1/2 years later.
mesh_terms: D002291:Carcinoma, Papillary / Q000473:pathology* / Q000601:surgery; D002471:Cell Transformation, Neoplastic; D003560:Cysts / Q000473:pathology*; D006801:Humans; D008206:Lymphatic Diseases / Q000473:pathology; D008297:Male; D008875:Middle Aged; D013950:Thymus Gland; D013953:Thymus Neoplasms / Q000473:pathology* / Q000601:surgery