Does "signet-ring stromal tumor" exist?

We have read with great interest the article of Simionescu C et al. (“Uterine pseudotumors”, Rom J Morphol Embryol, 2011, 52(3):743–748) [1]. This authors described “signet-ring stromal tumor” (SRST) and consider this lesion as “an unusual reactive process, which is suggested to be more frequent that it has been thought”. The microscopic illustration of the lesion is not reported. This pathological entity does not exist. The citations of the Simionescu C et al. are wrong because the content does not regard SRST. The paper of Cappellari JO et al. [2] describes a lymph node lesion: “Signet-ring cell sinus histiocytosis, a previously unrecognized histologic nodal condition mimicking metastatic adenocarcinoma”. Guerrero-Medrano J et al. [3] have reported “signet-ring histiocytosis” in four of 316 radical prostatectomy specimens (1.2%) and in two of 184 axillary dissections (1.08%). This finding can be confused with metastatic adenocarcinoma. The observations of Cappellari JO et al. and GuerreroMedrano J et al. regard lymph nodal pathology. Consequently, this finding does not support the existence of SRST. Occasionally, signet-ring cells of non-epithelial origin are found in the endometrium. Decidualized or pseudodecidualized endometrial stromal cells may have a signet-ring appearance, or may be histiocytes [4–6]. In the first case, the presence of decidualized stromal cells without a signet-ring morphology assists in diagnosis. Histiocytes, some of which may have signet-ring morphology, usually occur as aggregates within the endometrial stroma or lying free. The absence of staining with broad-spectrum cytokeratins and epithelial markers in both decidualized stromal cells and histiocytes assists in problematic cases. CD68 immunostaining assists in confirming the presence of histiocytes that often have characteristic “coffee-bean” nuclei. We have also observed signet-ring cells-like of stromal origin in the endometrium secondary to the effects of cautery. It is evident that these alterations are not defined for the neoplastic nature, as the “tumor” term implied. We believe that the lesion reported by Simionescu C et al. [1] is an “epithelioid leiomyoma, clear cell subtype” [7].