RENAL CELL CARCINOMA ARISING FROM MULTILOCULAR CYSTIC NEPHROMA OF THE
AHMAD M. OMAR, ALTAF Q. KHATTAK, JOHN A. LEE
Departments of Urology and Histopathology, Rotherham General Hospital United Kingdom, and Hull York Medical School, United Kingdom
Multilocular cystic nephroma is an uncommon benign entity grouped among the cystic non-genetic diseases. It is characterized by variable-sized, non-communicating cysts separated by irregular thin walled septa. Though multilocular cystic nephroma is usually considered a benign lesion, malignant changes in the cysts should not be overlooked.
words: kidney; cyst; renal cell carcinoma
The kidneys are prone to a variety of cystic disorders that includes developmental, acquired, and neoplastic lesions. However, the synchronous occurrence of two different renal tumors in the same kidney is a rare event. Here we report a case of cystic renal cell carcinoma arising in a multilocular cystic nephroma in a 65-year-old woman.
65-year-old white woman presented with a 10-month history of weight loss
and malaise. There was no history of urinary or bowel symptoms. A mass
was palpated in the right loin. Urine analysis was normal and urine cytology
was negative for malignancy. Full blood count, liver function tests and
renal function tests were all normal. An ultrasound scan showed a large
complex mass arising from the lower pole of the right kidney. CT scanning
displayed a huge multilocular heterogeneous mass in the lower pole of
the right kidney (Figure-1). The differential diagnosis of a malignant
versus a benign lesion was not possible with imaging, and a right radical
nephrectomy was performed.
etiology of multilocular cystic nephroma (MCN) has been the subject of
controversy for a long period of time. However, many currently believe
that MCN is a benign neoplasm and lies at the benign end of a continuum
that includes the cystic partially differentiated nephroblastoma (CPDN)
variants of Wilms’ tumor (1,2).
CONFLICT OF INTEREST
Epithelial hyperplasia evolving to neoplasia is common to several forms of human renal cystic disease, both congenital and acquired. Most frequently occurs in von Hippel-Lindau disease, a dominantly inherited syndrome of cerebellar and retinal hemangioblastomas, pancreatic, epididimal and renal cysts and tumors. Tumors also occur in acquired renal cystic disease in end-stage kidneys especially those of patients on long-term hemodialysis, in the dominantly inherited disorder tuberous sclerosis complex and, less frequently, in the adult polycystic renal disease. The arising of cystic renal cell carcinoma from multilocular cystic nephroma is a very controversial condition. The present case is worth reporting because the multilocular cystic nephroma is well documented. Thin septa of either fibrous tissue or resembling ovarian stroma are present and covered by flattened or low cuboidal epithelium with small amounts of cytoplasm occasionally with hobnail appearance. However, this cystic lesion may be coincidental to the renal cell carcinoma. Many other cases should be reported in order to consider cystic multilocular nephroma a predisposing lesion to kidney neoplasias.