Extragastrointestinal stromal tumor arising in the vulva and rectovaginal septum：a clinico-pathologic analysis of three cases / 临床与实验病理学杂志

ABSTRACT

Purpose To study the clinic-pathological features, differential diagnosis and prognosis of extragastrointestinal stromal tumor ( EGIST) arising in the vulva and the rectovaginal septum. Methods Clinical manifestations, pathological features, immunohisto-chemistry, gene mutations, treatment and prognosis were analyzed in 1 case of EGIST arising in the vulva and 2 cases of EGIST arising in the rectovaginal septum with review of related literature. Results Case 1 was a 59-years-old woman who was found to have a 4. 4 cm × 3 cm × 3 cm recurrent mass in the right vulva after 6 months of the first resection. Case 2 was a 58-years-old woman who presen-ted with a 7. 3 cm × 6. 1 cm × 4. 6 cm mass in the rectovaginal septum. Case 3 was a 41-year-old woman who presented with an 8. 6 cm × 7. 4 cm × 6. 7 cm mass in the rectovaginal septum. Histologically, the uniform spindle cells showed the interlacing fascicular, whirl-pool and palisade patterns with high cellular density. Mitotic figures were readily identified. Immunohistochemical evaluation revealed that the tumor cells exhibited strong and diffuse staining for CD117, CD34, NES, H-Caldesmon and DOG-1. Molecular analysis showed the gene mutation of c-Kit exon 11 in all 3 cases. Conclusion EGIST should be considered in the differential diagnosis of the mesenchymal tumors arising in the vulva and the rectovaginal septum. The immunohistochemical evaluation and molecular genetic tes-ting are crucial tools for the differential diagnosis and assessment of the prognosis and targeted therapy of EGIST.