Abstract
OBJECTIVE: To investigate and summarize the clinicopathological features, immunophenotype, differential diagnosis and prognosis analysis of mucinous tubular and spindle cell carcinoma (MTSCC). METHODS: The data of thirteen cases of MTSCC were retrospectively analyzed, the clinical and pathological characteristics and immunohistochemical expression were summarized, and fluorescence in situ hybridization was detected. RESULTS: Among the thirteen patients, four were males and nine females, with a male-to-female ratio of 1 ∶2.25. The average age was 57.1 years, ranging from 39 to 78 years. The maximum diameter of the tumor was 2-12 cm. All cases had no symptoms, and were accidentally discovered, 3 cases underwent partial renal resection, 10 cases underwent radical renal resection, 9 cases were located in the left kidney, and 4 cases were located in the right kidney. Most of the cases showed the classical morphological changes, with 11 cases of nuclear grading [World Health Organization (WHO)/International Society of Urological Pathology (ISUP) grading system] being G2 and 2 cases being G3. There were 6 cases of stage PT1a, 3 cases of PT1b, 2 cases of PT2a, and 1 case of PT2b and 1 case of PT3a. The positive rates of immunohistochemical staining were: vimentin, AE1/AE3, α-methylacyl-CoA racemase (αMACR) and cytokeratin (CK) 8/18, 100% (13/13); CK7, 92.3% (12/13); epithelial membrane antigen (EMA), 92.3% (12/13); CK20, 46.2% (6/13); CD10, 30.8% (4/13); synaptophysin (Syn), 7.7% (1/13); chromogranin A (CgA), CD57, WT1 and Ki-67, 0 (0/13), and fluorescence in situ hybridization showed that no trisomy of chromosomes 7 and 17 were observed in any of the cases. The follow-up period was 6 months to 7 years and 6 months, 2 cases died after lung metastasis (one with ISUP/WHO grade G3, one with necrosis), and the remaining 11 cases had no recurrence and metastasis. CONCLUSION: MTSCC is a unique type of low-grade malignancy kidney tumor, occurs predominantly in females, widely distributed in age, the current treatment method is surgical resection, and cases with necrosis and high-grade morphology are prone to recurrence and metastasis, although most cases have a good prognosis, but they still need close follow-up after surgery.