Renal mucinous tubular and spindle cell carcinoma (RMTSCC) is a relatively rare type of malignancy arising from renal parenchyma, which can be characterized by tiny, long tubules lined by cuboidal cells with or without spindled cells separated by pale mucinous stroma.1 Although RMTSCC is described in the previous literature as a low‐grade tumor, it has a wide range of histological spectrum ranging from low to high grade, sometimes leading to dismal prognosis. To date, number of the literatures are limited up to around hundred, the biological behavior and clinical outcomes, especially metastatic potential of RMTSCC is to be undefined.1, 2 More recently, Wang et al. found chromosomal losses and somatic mutations of genes in the Hippo pathway in RMTSCC.3 They performed an integrative analysis of 907 renal cell carcinoma samples from in‐house and TCGA dataset and identified VSTM2A and IRX5 as novel cancer‐specific biomarkers in MTSCC.3 The majority of non‐RMTSCC tumors demonstrated negative or low expression of VSTM2A, while IRX5 being suggested as a lineage‐specific biomarker, showing moderate to high expression in MTSCC tumors.3 There are some metastatic RMTSCC cases which are linked to sarcomatoid differentiation.4, 5 Given all these facts, clinicians better be aware that patients with RMTSCC especially with sarcomatoid features should undergo frequent medical checkup according to high grade clear cell carcinoma after surgery even with curative intent.
Conflict of interest
The authors declare no conflict of interest.
References
- 1. Ren Q, Wang L, Al‐Ahmadie HA et al Distinct genomic copy number alterations distinguish mucinous tubular and spindle cell carcinoma of the kidney from papillary renal cell carcinoma with overlapping histologic features. Am. J. Surg. Pathol. 2018; 42: 767–77. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2. Kuthi L, Jenei A, Hajdu A et al Prognostic factors for renal cell carcinoma subtypes diagnosed according to the 2016 WHO renal tumor classification: a study involving 928 patients. Pathol. Oncol. Res. 2017; 23: 689–98. [DOI] [PubMed] [Google Scholar]
- 3. Wang L, Zhang Y, Chen YB et al VSTM2A overexpression is a sensitive and specific biomarker for mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney. Am. J. Surg. Pathol. 2018; 42: 1571–84. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Ursani NA, Robertson AR, Schieman SM, Bainbridge T, Srigley JR. Mucinous tubular and spindle cell carcinoma of kidney without sarcomatoid change showing metastases to liver and retroperitoneal lymph node. Hum. Pathol. 2011; 42: 444–8. [DOI] [PubMed] [Google Scholar]
- 5. Kenney PA, Vikram R, Prasad SR et al Mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney: a detailed study of radiological, pathological and clinical outcomes. BJU Int. 2015; 116: 85–92. [DOI] [PubMed] [Google Scholar]