Metastatic biphasic synovial sarcoma of bony pelvic mimicking Direct inguinal hernia: rare case report

Synovial sarcoma)SS) is an aggressive soft tissue tumor.It usually occurs in the extremities near the large joints, but has been reported at uncommon sites such as abdominal wall,esophageal area, etc.SS has poor long‐term prognosis due to later recurrences and metastasis.biphasic synovial sarcoma of Abdomino-pelvic region extended to inguinal area never has been reported in the literature. We report case of 31-year-old man presenting with urine retention,dysuria, vomiting,weight loss and pain in the right lower limb.Physical examinations revealed mass in inguinal area without any large lymph nodes. Low grade lymphocytosis was seen (55%)in CBC. By the patient clinical manifestations the first diagnose was direct inguinal hernia.Ultrasound(US) of lower abdomen and pelvic area showed heterogeneous hypoechoic mass with internal septation. Increased vascularity was demonstrated on color Doppler ultrasound.MRI showed round mass with 5×4×1 cm in diameters causing bony destruction and compression of pelvic viscera.Pathology result of core needle biopsy was cells with round to oval vesicular nuclei,acidophilic cytoplasm,moderate pleomorphic and mitotic figures.Surgical team selects total inguino pelvic mass resection and after one week,he discharged with good condition.We followed up him and ultrasound of pelvic area performed every month.After 36 months (3years) US indicated several large inguinal lymph nodes. Result of core needle biopsy was carcinoma metastasis to lymph nodes and IHC confirmed following results:CK AE1/AE3 and EMA:Positive in epithelioid component,CK5/6:Focal positive in epithelioid component,BCL2:Focal and weakly positive,Vimentine:positive,NSE:Positive(Double-checked),Ki67:10-11% neoplasticcells.Diagnose was metastatic biphasic synovial sarcoma.Patient underwent three time neoadjuant chemotherapy (Doxorubicin,Ifosfamide, GCSF)and radiotherapy.After these presurgical operation,total inguinal lymphadenectomy was performed with adjuvant chemoterapy.three days later the patient discharged and followed up for18 month.The overall survival of patients with this tumor is 36-76% in years and 20-63% in10 years.The prognosis depends on histological type and immune phenotype.Other predictive factors are patient’s age,tumor size and number of mitoses.

کلیدواژه ها:

Keywords: soft tissue tumor ، biphasic synovial sarcoma ، inguinal hernia