Carcinoma Renal Mucinoso de Células Tubulares e Fusiformes: Características clínicas, patológicas e imagiológicas

Abstract

Background: Mucinous Tubular and Spindle Cell Carcinoma (MTSCC) is a rare variant of Renal Cell Carcinoma (RCC). MTSCC has been regarded has an indolent subtype of RCC conveying a good prognosis. However recently, some cases of MTSCC have been described presenting or evolving with metastasis, showing an aggressive behavior. We aim to describe MTSCC clinical characteristics, treatment, prognosis, and survival. Methods: We retrospectively reviewed all cases of MTSCC diagnosed at our institution from 1st January 2008 to 31st December 2022. Electronic health records were reviewed, and data was retrieved and analyzed. This study was approved by our institution's ethics committee. Data confidentiality was assured. Results: We identified 8 cases of MTSCC among the 15 years of the study timeframe diagnosed in our hospital. Median age at diagnosis was 59 years (range 32 - 80) and half of the patients were women (n=4, 50%). In 6 of the patients (75%) presentation was incidental, while the other two presented with flank pain. One patient had metastasis at presentation, while the remaining cases were localized at the time of diagnosis. Six patients were submitted to radical nephrectomy: 4 by open approach and 2 by transperitoneal laparoscopic approach. Two patients were submitted to a partial nephrectomy by an open approach. Mean (SD) post operative hemoglobin drop was 2,18 (1,12) g/dL. Median follow up was 36,5 months (range 2- 157). During the study timeframe no other patients were diagnosed with local recurrence or distant metastasis. Two patients died during follow up: the one that was metastatic at diagnosis died due to disease progression two months after surgery and another died due to a competitive disease (acute lower limb ischemia). Conclusion: MTSCC is a rare variant of RCC that despite being initially regarded as an indolent disease with a good prognosis might harbor an aggressive behavior and grim prognosis.