[Mucinous tubular and spindle cell carcinoma of kidney: Clinicopathology and prognosis].

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.