关键词:
Dedifferentiation
Kidney
Malignant
Soft tissue neoplasms
Solitary fibrous tumor
STAT6
STAT6
摘要:
Objective To explore the clinicopathological features, immunophenotype, molecular characteristics, and prognosis of primary malignant solitary fibrous tumor (MSFT) of the kidney. Methods The clinicopathological data of four renal MSFT cases diagnosed at the Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China and one case at the Ningbo Clinical Pathology Diagnostic Center, Ningbo, China between 2015 and 2025 were collected. The clinical features, histomorphology, and immunohistochemical characteristics were analyzed. Fluorescence in situ hybridization (FISH) and RNA-based next-generation sequencing were performed. Follow-up and review of relevant literature were conducted. Results Among the five patients, three were male and two were female, aged 70(61,71) years. The tumors were all found during routine physical examinations. Four cases (cases 1, 3, 4, and 5) occurred in the left kidney, and one case (case 2) first occurred in the left kidney and recurred in the right kidney 5 years later. Four cases had a single lesion with a maximum diameter of 6.0-19.0 cm, and one case (case 5) had 2 lesions with maximum diameters of 2.0 cm and 4.0 cm, respectively. Histologically, three cases (cases 1, 2, and 5) were de novo MSFT, one case (case 5) was morphologically similar to synovial sarcoma with spindle cells arranged densely in bundles, one case (case 1) had sheets of epithelioid tumor cells, and one case (case 2) had alternating myxoid and spindle cell areas, with sparse tumor cells in the myxoid areas and dense tumor cells in the spindle cell areas. Two cases (cases 3 and 4) were classic solitary fibrous tumor (SFT) with dedifferentiation, and the dedifferentiated components were high-grade undifferentiated sarcoma. In the typical SFT areas, tumor cells were alternately dense and sparse, with collagenized areas and rare mitotic figures, while branching or hemangiopericytoma-like structures were also present. In the dedifferentiat