engleski

MULTILOCULAR CYSTIC RENAL CELL CARCINOMA: A CASE REPORT

Introduction The Bosniak classification categorizes each renal cystic mass as “nonsurgical” (ie, benign – categories I and II) or as “surgical” (ie, requiring surgery – categories III and IV). For the cysts slightly more complex than cysts in category II, but not complex enough to require surgical exploration as cysts in category III, a category IIF (F for follow-up) was introduced. The majority of the cystic renal carcinomas are presented as an obvious Bosniak “surgical lesion“. Today literature is lacking of imaging data about an uncommon subtype of cystic renal cell carcinoma (RCC), rarely presented as a cystic lesion of benign or likely benign characteristics, as it was in the following case report. Although the Bosniak classification is based on computed tomography (CT) findings, CT and magnetic resonance imaging (MRI) characterization of renal cysts are similar in most of the cases. However, some authors suggest MRI to find additional information, which may lead to inconsistent classification. This case report will also contribute to a very lacking comparison of two imaging techniques regarding this uncommon neoplasm. Case report A 51-year-old female presented with a persistent left flank pain. She underwent CT examination, followed by a MRI at our institution. CT revealed a well-defined multicystic mass lesion in the lower pole of the kidney, measuring 4.9 x 4.6 cm. After i.v. contrast administration, the mass showed poor rim enhancement and partial enhancement of several thin septations. MRI showed almost identical findings. The mass was finally classified as Bosniak category IIF lesion (likely benign). Despite the likely benign appearance on radiological evaluation, the patient underwent a partial nephrectomy. Pathohistological examination provided a definitive diagnosis of a multilocular cystic renal cell carcinoma (MCRCC). Patient continued to come on regular follow up examination at our institution, with no residual tumor detected. Conclusion Imaging techniques present MCRCC mainly as Bosniak “surgical“ category III, however the present case report suggests radiologists and urologists to keep in mind the likely benign appearance of this RCC subtype. In this case, MRI provided no additional data and confirmed Bosniak classification, but more comparisons are needed to provide stronger evidence. As patients with MCRCC have a great clinical outcome, the post-surgical follow-up interval can be longer to minimize unnecessary examinations as our patient still does

kidney, MCRCC, Bosniak classification, CT

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