Recurrence of composite hemangioendothelioma of the kidney after surgical resection

Abstract

Composite hemangioendothelioma is an extremely rare form of kidney tumor. The tumor mainly occurs in the extremities, head and neck; internal organs involvement is rarely reported. Patient, 61-year-old male, was admitted to the urology department for a left kidney tumor, which was found accidentally during an ultrasound examination. Magnetic resonance imaging showed an irregularly shaped tumor measuring 5.0 × 6.0 × 4.0 cm and located in the lower pole of the left kidney. The tumor was surgically removed with resection of the capsule of the kidney lower pole. Immunohistochemical study revealed diffuse bright expression of CD31 (clone JC70A), CD34 (clone QBEnd 10), ERG (clone ER111), FLI-1 (clone MRQ-1) in tumor cells. The index of proliferative activity Ki-67 (clone SP6) was 40 %. The morphological picture and immunophenotype of the tumor correspond to composite hemangioendothelioma of the retroperitoneal space. Magnetic resonance imaging of the retroperitoneal space on follow-up visit in 9 months visualized a tumor of the left kidney measuring 8.3 × 8.4 × 7.8 cm. Radical nephrectomy was performed. Pathology examination showed that tumor tissue was mainly represented by solid fields of the spindle cell component. In samples of the border between the tumor and fatty pararenal tissue, tumor invasion was observed up to the adjacent striated muscles, tumor growth into the tissue of the kidney gate was also found. Taking into account the morphological picture and the earlier immunohistochemical study, the removed tumor corresponds to composite hemangioendothelioma.Composite hemangioendothelioma is a tumor of low malignant potential. It is extremely rare for this tumor to affect the kidney. At the same time, in the described case, the tumor was initially located in the retroperitoneal space, with involvement of the kidney capsule, and was assessed as a benign lesion. After 9 months, there was a recurrence of the tumor localized in the kidney with damage to the elements of the renal sinus, retroperitoneal tissue, and lumbar muscles. In this case, the tumor has significant malignant potential.