Noncaseating granulomas in association with breast, liver, and colon carcinomas have been described [13
]. Non-necrotizing granulomatous reaction within the renal cell carcinomas (RCC) is rare with only a few published reports in the literature [16
]. The RCC described by Marinides et al. was of a papillary type. There is one case report of nonnecrotizing granulomas in RCC with sarcomatoid features [21
]. However, RCC in other reports, similar to our case, had a clear cell pattern with the presence of epithelioid granulomas. The current case report may indicate a possible association between preexisting clonal myelodysplasia and granulomatous reaction within the RCC.
Our patient has a long-standing history of clonal (5q minus) myelodysplastic syndrome associated with refractory normocytic anemia and small hypolobated megakaryocytes. The granulomas were exclusively associated within the RCC tumor and were entirely absent in the surrounding nonneoplastic renal parenchyma. Previous case reports of granulomatous RCC in a preexisting myelodysplasia have not been reported. However, a few case reports of sarcoidosis involving lung and skin have been associated with 5q minus syndrome [3
]. In our case, the patient did not have any history or symptoms suggestive of sarcoidosis. Except for a long standing refractory anemia, the biochemical, serological, and hematological parameters were within normal limits. The cases reported by Tunkel et al. and Airaghi et al. along with our present case report suggest a possible association between epithelioid granulomas and 5q minus myelodysplastic syndrome. The possibility of this association is further strengthened based on the evidence of clustering of genes encoding for Th-2 cytokines on long arm of chromosome 5. Hence, deletion of these genes may lead to cytokine imbalance and initiation of granuloma formation upon antigenic stimulation. Moreover, nonclonal myelodysplasia has been shown to be rarely associated with disseminated nonnecrotizing granulomatous skin eruptions [5
]. Hence, propensity to develop noncaseating epithelioid granulomas, in the setting of myelodysplasia, warrants further investigation.
In conclusion, this is the first reported case of multiple granulomas confined to a renal cell carcinoma in a patient with preexisting myelodysplastic syndrome. The hypothesis of existence of cytokine imbalance and uncontrolled activation of T cells and macrophages, in the setting of 5q minus myelodysplasia has been previously proposed [3
]. The present study provides further support to this hypothesis. However, unlike previous studies, these granulomas were confined to the renal cell carcinoma in the setting of preexisting blood dyscrasia. Further studies may potentially look more closely at the possible association of myelodysplasia and immune activation leading to formation of epithelioid granulomas.