Solitary Fibrous Tumors of the Kidneys: Presentation, Evaluation, and Treatment

Abstract

Introduction: Renal solitary fibrous tumors (SFTs) are spindle cell neoplasms of mesenchymal origin, and very rare with only 46 cases reported worldwide to date. It is crucial to differentiate this tumor from other tumors of the kidney, so as to avoid unnecessary treatment. Therefore, our objective was to review reports of renal SFTs, their clinical presentations, imaging methods, and surgical management, updated to 2013. Material and Methods: We retrospectively reviewed articles published in the USA, Europe, and Asia from 1996 to date using PubMed, Medscape, Medline, and several major journals. We report on areas of controversy and well-established guidelines. Results: We reviewed 58 articles which confirmed, with a high level of evidence-based medicine, that the male-to-female ratio is equal and their most common presentation is an incidental finding on a radiological study, in which it is difficult to differentiate them from renal cell carcinoma. Nephrectomy is the gold standard treatment, with almost no recurrence. Conclusions: In symptomatic patients, complete surgical resection of renal SFTs may provide a very good outcome, with almost no recurrence.

Solitary fibrous tumour of the genitourinary tract: a clinicopathological study of 11 cases and their association with theNAB2-STAT6fusion gene

“…An additional study of renal solitary fibrous tumours (n=46) also reported many of the same clinicopathological features found in the cases of this study 27. In these published studies, however, variables related to malignant clinical behaviour were histological (mitotic activity, pleomorphism and cellularity).…”

Malignant Solitary Fibrous Kidney Tumor with Peritoneal Disease: A Case Report

“…Clinically, some cases, including the present one, can appear as palpable abdominal mass or intestinal obstruction [7] and begin as abdominal pain or gross hematuria. A CT scan is not able to distinguish between carcinomas or sarcomas, and diagnosis is frequently made postoperatively [4].…”

“…Malignant solitary fibrous tumor is usually solitary, varies in size and appears in different cystic areas, with hemorrhage or necrosis present [7]. Microscopically, it is characterized by both hyper- and hypocellularity, and mitotic activity is between 4–10/10 high-power fields [2].…”

“…A differential diagnosis must be made between other mesenchymal tumors such as leiomyoma or leiomyosarcoma, sarcomatoid renal tumor and transitional cell carcinoma [3, 7]. …”

Radiological diagnosis of perinephric pathology: pictorial essay 2015

“…Initially believed to be solely a pleural malignancy, referred to as “benign fibrous mesothelioma”, SFTs can be seen anywhere throughout the body [72, 73]. Most SFTs are benign and appear as slow-growing masses in middle-aged adults, with equal frequency in men and women [74, 75].…”