Cystic renal cell carcinoma: pathological features, survival and implications for treatment

Abstract

Objectives To assess the incidence, clinicopathological features, prognosis and therapeutic options of cystic renal cell carcinoma (CRCC). Patients and methods The clinical records and nephrectomy specimens from 206 patients with renal cell carcinoma (RCC) were reviewed after a minimum follow‐up of 5 years. The mode of presentation, tumour size, growth pattern, nuclear grade, cytoplasmic appearance and pathological stage at presentation were compared with the outcome, as measured by disease‐free and overall survival of the patients. Results From the 206 patients with RCC, 25 (12%) were classified as having CRCC; most of these cases (96%) occurred in male patients, as opposed to 64% in the remaining patients RCC (P=0.0029). The clinical features at diagnosis were similar in both groups, although asthenia, anorexia and weight loss were uncommon in patients with CRCC (P=0.045). Nuclear grade and pathological stage were usually lower in those with CRCC than in those with RCC (P=0.0071 and P=0.0033, respectively). Survival was significantly longer in patients with CRCC (P=0.0342). Conclusions CRCC is a type of RCC that is usually identified at earlier stages, has a slower growth rate, and is therefore associated with a better prognosis and longer survival than conventional RCC. The differential diagnosis between CRCC, cystic multilocular nephroma and cysts with a superimposed infectious or haemorrhagic process can be extremely difficult in imaging studies, and even in intra‐operative frozen‐section analysis. Because of this, and with the better prognosis of CRCC, a conservative surgical approach would be the treatment of choice whenever technically feasible.

CD2-associated protein in human urogenital system and in adult kidney tumours

“…The classification of cystic RCCs has been controversial, since some authors consider multilocular cystic RCC as a clinicopathological entity, whereas others suggest that it is a variant of conventional clear cell RCC [4,27,29]. In this respect, it is significant that the neoplastic epithelium lining the cysts in multilocular cystic RCCs was distinctively more strongly CD2AP positive than the solid-type clear cell RCCs.…”

CUA guideline on the management of cystic renal lesions

“…11,12,15,[23][24][25][26][27]31,33,34,39,40,42,43,47,51,59 However, the literature is thought to overestimate the true risk of malignancy among category II cysts, as the majority were managed conservatively or had features that made them too complex to be categorized as a Bosniak II cyst. 6,12,26,29,31,32,35,38,59 Importantly, even if malignant, most behave in a relatively benign fashion.…”

“…mcRCCs have consistently fared better than their counterparts on both cancer-specific and overall survival. 24,[66][67][68][69][70][71][72][73] One potential explanation for this better prognosis is that the majority of mcRCCs tumour volume is fluid and thus, the actual tumour burden is much lower when compared to similar sized solid tumours. 67 As the outcomes of these tumours do not seem to be influenced by the overall lesion size, some experts have even suggested to abandon the current pathological T staging for mcRCC and to reassigned them a new stage called pT1c (c for cystic).…”

Transplantation of kidneys with tumors

“…Necrosis, fibrosis and/or a cystic tumor component raises the percentage of false negative results in fragmentary samples (27)(28)(29). Moreover, in frozen tissue the cytology and sometimes the architecture too may not be well preserved so that a specific diagnostic feature, clearly appreciable on paraffin sections, may not be evident on frozen sections.…”