Type IX Ehlers-Danlos syndrome: bladder diverticula with transitional cell carcinoma.

Patients with type IX Ehlers-Danlos syndrome have a tendency for development of diverticulae of the urinary bladder, and these often recur after surgical excision. We report on a patient with this syndrome in whom an extensively infiltrating transitional cell carcinoma developed in a diverticulum. To our knowledge, this is the first reported case of malignancy developing in a patient with type IX Ehlers-Danlos syndrome. The highly aggressive nature of the neoplasm is discussed in relation to the dampened desmoplastic response to the tumor, observed in this patient.