Unusual Morphologic Features of Endometrial Stromal Tumors

Abstract

Endometrial stromal tumors with typical morphology usually do not pose diagnostic problems. However, the finding of unusual morphologic features may be misleading in the final interpretation of these tumors. Herein, we described two endometrial stromal sarcomas discovered in hysterectomy specimens of women 31 and 75 years of age. Features typical of endometrial stromal neoplasia were present in both cases. Additionally, in 1 case, extensive fatty metaplasia as well as smooth and skeletal muscle metaplasia were found; and in the second case, focal bizarre nuclei, smooth muscle differentiation, and fibrous change were present. The differential diagnosis in the first case included cellular intravenous leiomyomatosis/lipoleiomyomatosis with skeletal muscle differentiation; and in the second case, a cellular smooth muscle tumor with bizarre nuclei was considered.

Endometrial stromal tumours of the uterus: a practical approach using conventional morphology and ancillary techniques

“…52 Fatty metaplasia and bizarre nuclei have recently been reported in these tumours. 68 In this category, the most common problems in differential diagnosis-namely, smooth-muscle and sex cord-like differentiation-will be discussed.…”

Novel High-grade Endometrial Stromal Sarcoma

“…7–9 A myriad of variant histologic features have been described, including smooth muscle, glandular, sex-cord, and rhabdomyoblastic differentiation, as well as myxoid/fibromyxoid, fibrous, pseudopapillary, and epithelioid change. 7,10–21 By immunohistochemistry, LG-ESS is positive for estrogen receptor (ER), progesterone receptor (PR), and CD10. 22–24 Approximately half of LG-ESS harbor t(7;17) chromosomal translocations resulting in JAZF1-SUZ12 gene fusion.…”

Uterine mesenchymal tumors: a review of selected topics

“…They include otherwise typical endometrial stromal sarcomas that include smooth muscle (Figure 3), 7,[16][17][18][19][20] myofibroblasts, 20 fibroblasts ( Figure 4) 7,20,21 (with or without myxoid stroma), sex cord and/or epithelioid elements ( Figure 5), 7,22-24 endometrioid glands 7,17,[24][25][26] and, rarely, skeletal muscle. 27 Occasional examples may also demonstrate rhabdoid or adipose-like features. 27 The clinical correlates of these histologic variants have not been studied in detail.…”

“…27 Occasional examples may also demonstrate rhabdoid or adipose-like features. 27 The clinical correlates of these histologic variants have not been studied in detail. It is not yet certain whether tumors containing both stromal and smooth muscle elements should be considered endometrial stromal tumor variants or mixed endometrial stromal and smooth muscle tumors.…”