Multilocular cystic renal tumours (MCRT) are rare benign renal neoplasms occurring in a bimodal age distribution, involving young children and adults in the 4th and 5th decades.
For logical reasons, this article will discuss together the two ends of the spectrum of this disease, cystic partially differentiated nephroblastoma (CPDN) and cystic nephroma, as they are indistinguishable from one another based on radiographic appearances and gross pathology.
These tumours are rare and have a bimodal age and sex distribution:
- paediatric (3 months to 4 years of age) - 75% male predilection
- adult (typically in the 5th - 6th decades) - females are predominantly affected
In paediatric patients, a multilocular cystic nephroma usually present as an asymptomatic palpable abdominal mass felt by parents, with increasing abdominal girth. It may also present with haematuria or possibly urinary tract infection.
Grossly, multilocular cystic renal tumours are typically unifocal multiloculated cystic masses surrounded by a thick fibrous capsule and compressed parenchyma 8. Calcification, haemorrhage, and necrosis are unusual.
Microscopically, these tumours are lined by flat, cuboid, or hobnail cells 8, while the fibrous septa may contain mature tubules 3.
Multilocular cystic renal tumours generally have the appearance of a multilocular cystic encapsulated mass on most modalities.
May present as a large abdominal mass displacing and effacing adjacent bowel loops.
- multilocular cystic mass originating from kidney 4
- claw or beak-shape of adjacent renal parenchyma (claw sign) may help confirm a renal origin
- cyst contents usually anechoic, but low-level echoes may be seen
- septal vascularity can also be seen 8
- multilocular cystic mass often herniates into the renal pelvis
- variable septal enhancement
- no nodular or solid enhancement 8
- +/- associated streakiness in perirenal fat 4
Signal characteristics include:
- T1: variable signal, depending on the protein or blood products of the cysts
- T2: hyperintense (cysts)
- T1 C+ (Gd): septal enhancement may be seen
Treatment and prognosis
Radical or partial nephrectomy is usually done, with lymph node excision.
In an adult population, it is indistinguishable from multilocular clear cell renal cell carcinoma.
In a paediatric population, it is often difficult to distinguish cystic Wilms tumour from the multilocular cystic renal tumours:
- solid nodular components in a tumour should arouse suspicion of Wilms tumour 9
- MCRT tends to occur in younger children than Wilms tumours
Multicystic dysplastic kidney (MCDK) is a developmental anomaly in which the entire kidney is replaced by noncommunicating cysts of varying sizes. It is usually diagnosed prenatally or at birth, while multiloculated cystic renal tumours do not occur in the perinatal period 8. In addition, enhanced compressed renal parenchyma is seen to surround cystic nephroma on contrast-enhanced cross-sectional studies, while this tissue is absent in MCDK.
- 1. Umar V, Abbas AK, Fausto N et-al. Robbins and Cotran pathologic basis of disease. W B Saunders Co. (2005) ISBN:0721601871. Read it at Google Books - Find it at Amazon
- 2. Weissleder R, Wittenberg J, Harisinghani MG. Primer of diagnostic imaging. Mosby Inc. (2003) ISBN:0323023282. Read it at Google Books - Find it at Amazon
- 3. Guermazi A. Imaging of kidney cancer. Springer Verlag. (2006) ISBN:3540211292. Read it at Google Books - Find it at Amazon
- 4. Silver IM, Boag AH, Soboleski DA. Best cases from the AFIP: Multilocular cystic renal tumor: cystic nephroma. Radiographics. 28 (4): 1221-5. doi:10.1148/rg.284075184 - Pubmed citation
- 5. Madewell JE, Goldman SM, Davis CJ et-al. Multilocular cystic nephroma: a radiographic-pathologic correlation of 58 patients. Radiology. 1983;146 (2): 309-21. Radiology (abstract) - Pubmed citation
- 6. Federle MP, Jeffrey RB, Woodward PJ et-al. Diagnostic Imaging: Abdomen, Published by Amirsys®. Lippincott Williams & Wilkins. (2009) ISBN:1931884714. Read it at Google Books - Find it at Amazon
- 7. Hill DA, Ivanovich J, Priest JR et-al. DICER1 mutations in familial pleuropulmonary blastoma. Science. 2009;325 (5943): 965. doi:10.1126/science.1174334 - Free text at pubmed - Pubmed citation
- 8. Chung EM, Graeber AR, Conran RM. Renal Tumors of Childhood: Radiologic-Pathologic Correlation Part 1. The 1st Decade: From the Radiologic Pathology Archives. Radiographics. 2016;36 (2): 499-522. doi:10.1148/rg.2016150230 - Pubmed citation
- 9. Sanchez TR, Ducore J, Balagtas J et-al. WARM N COLD: malignant and benign renal tumors in children. Emerg Radiol. 2014;21 (3): 261-9. doi:10.1007/s10140-014-1202-8 - Pubmed citation