A p16 positive pleomorphic endometrial stromal sarcoma: an unusual case scenario

Endometrial stromal tumors are rare uterine malignancies, particularly in young women, and are divided into four typesSarcomas [UUS]. A fifth category of Endometrial Stromal Sarcomas - Not Otherwise Specified [ESS NOS] has also been kept for tumours with a predominantly high grade morphology showing significant LG ESS areas as well. Herein, we report a case of a 26 year old woman who presented with an abdominal mass and bleeding per vaginum. Abdomino pelvic ultrasound revealed a neoplastic polypoidal lesion. Post hysterectomy, histopathological examination revealed a tumour mass with features of a highly pleomorphic high grade endometrial stromal sarcoma [HGESS] along with concomitant features of low grade endometrial stromal sarcoma [LGESS] as well. Application of IHC panel further revealed that the tumor came out to be immuno reactive for vimentin, cyclin D1, INI1 and p-16 with focal positivity for Calretinin, Glypican 3 and CD99, the demonstration of p16 positivity being highly unusual for a HGESS. As the patient's condition deteriorated rapidly and she expired soon after the initial examination started, molecular profiling could not be done.