Hygroma renalis: two cases within a family and a literature review

Hygroma renalis is an unusual benign tumor of the kidney. Only 24 cases have been reported previously in the world literature; 22 of these patients underwent nephrectomy. Two sisters, with the first known occurrence in siblings, are discussed and the world literature is reviewed. Our first patient underwent nephrectomy for complications of hygroma in the face of a concern for a renal malignancy, but a high index of suspicion for hygroma enabled the second sibling to undergo a less radical operation, with sparing of the renal parenchyma and function. Both patients have been followed up for more than 3 years, with no evidence of recurrence of the neoplasm. Computed tomography was effective in delineating the nature and extent of disease in both patients and was instrumental in allowing conservative management of the second patient. Renal hygroma is a benign neoplasm treated adequately with conservative management and can be identified by its characteristic appearance on computed tomography. Operation should be reserved for the complications of hygroma. When operation is undertaken, resection of the hygroma without nephrectomy is adequate; radical operation is contraindicated in the management of these patients.