Renal malignant solitary fibrous tumor with single lymph node involvement: report of unusual metastasis and review of the literature

Abstract

Solitary fibrous tumors are rare mesenchymal spindle cell neoplasms that are usually found in the pleura. The kidneys are an uncommon site and only few cases of renal solitary fibrous tumor exhibit malignant behavior metastasizing to the liver, lung, and bone through the hematogenous pathway.PurposeTo describe the first case of lymph node metastasis from renal solitary fibrous tumor in order to increase the knowledge about the malignant behavior of these tumors.Patients and methodsA 19-year-old female patient had intermittent hematuria for several months without flank pain or other symptoms. A chest and abdomen CT scan was performed and showed a multi-lobed bulky solid mass of 170 × 98 × 120 mm in the left kidney. One day before the surgery, the left renal artery was catheterized and the kidney embolization was performed using a Haemostatic Absorbable Gelatin Sponge and polyvinyl alcohol. We then performed a radical nephrectomy with hilar, para-aortic, and inter-aortocaval lymphadenectomy.ResultsEstimated intraoperative blood loss was 200 mL and the operative time was 100 minutes. No postoperative complications occurred. The hospital stay was 7 days long. The histological examination was malignant solitary fibrous tumor of the kidney. Cancerous tissue showed cellular atypia, with an increased mitotic index (up to 7 × 10 hpf). Immunohistochemical analysis showed positive results for CD34, BCL2, partial expression of HBME1, and occasionally of synaptophysin. Histological evaluation confirmed the presence of metastasis in one hilar node. The patient did not receive any other therapy. At 30-month follow-up, the patient was in good health and no local recurrence or metastases had occurred.ConclusionThis is the first case of lymph node metastasis from a renal solitary fibrous tumor showing unusual malignant behavior; this finding adds new information about the biology and progression of these tumors, which remain unclear.

Primary angiosarcoma of the kidney: case report and comprehensive literature review

“…AS unusually harbours from the kidney, and it was first described by Prince in 1942 [18], after a clear definition of this heterogeneous group of the tumour was set [19, 20]. Numerous overlapping radiological characteristics could be observed in particular with RCC [14, 21, 22].…”

A broad ligament solitary fibrous tumor with Doege–Potter syndrome

“…Hence, it is reasonable to treat all SFTs under the assumption that they are highly invasive. Mearini et al [ 14 ] reported a patient with a renal SFT that was difficult to diagnose definitively during the surgery; therefore, lymphadenectomy was performed after which lymph node metastases were discovered after the operation. A 64-year-old patient underwent mass resection, hysterectomy, bilateral salpingo-oophorectomy, and supplementary surgery involving inguinal lymph node dissection for malignant vulval SFT; however, she died of cancer metastasis.…”

A GRIA2 and PAX8-positive renal solitary fibrous tumor with NAB2-STAT6 gene fusion

“…SFT in the kidney is mostly benign but has malignant potential. Recently, there has been an increase in the number of reports of malignant SFT, including metastasis to lymph nodes [ 12 ], lung [ 10 , 13 , 14 ], liver [ 13 , 14 ], pancreas [ 11 ] and bone [ 15 , 16 ], local recurrence [ 17 , 3 ], peritoneal implantation [ 3 ], and invasion to renal vein [ 18 ]. Microscopically, the diagnostic criteria for malignant SFT is the presence of increased cellularity with crowded and overlapping nuclei, pleomorphism, necrosis and hemorrhage, increased mitotic activity more than four mitoses per ten high power fields (HPFs) [ 19 , 8 , 7 ].…”