[Ultrasonographic aspects of kidney pelvis tumors associated with infectious hydronephrosis of lithiasic origin].

The ultrasonographic findings of 4 patients with surgically confirmed urothelial tumors associated with calculic pyonephrosis are presented. All the involved were markedly enlarged and hydronephrotic with obstructive calculi, stigmata of pyonephrosis and, an echoic pelvic mass, extending in calyceas in 2 cases. The sonographic appearance correlated well with the gross pathological findings. The histological types were 2 squamous cell carcinomas, 1 adeno-squamous cell carcinoma and 1 transitional carcinoma. The chronic calculic irritation was proved to induce squamous and glandular metaplasia. The subsequent squamous carcinoma and adenocarcinoma were documented in the literature. The preoperative diagnosis of the associated tumor was rarely done. The sonographic features reported are highly suggestive of urothelial tumor and may lead to an accurate preoperative diagnosis.