Angiosarcoma of the Seminal Vesicle: A Case Report of Long-Term Survival Following Multimodality Therapy
A previously healthy 45-year-old male developed sharp left lower quadrant and groin pain. He was evaluated by his primary physician and his symptoms were thought to be related to diverticulitis. He was treated conservatively with an antibiotic, though there was no resolution of his symptoms.\nA computed tomography (CT) scan of the pelvis revealed a 5.6×5.1 cm heterogeneously enhancing mass involving the left lobe of the seminal vesicle and minimally the right lobe across the midline. The mass was invading the left bladder base and ureterovesicular junction (UVJ), and a few cm of left distal ureter (). This was accompanied by left-sided hydronephrosis. The mass also invaded the left obturator internus muscle, and potentially the base of prostate gland as well as into the perirectal space abutting the rectum. There was no pelvic lymphadenopathy. A transrectal biopsy of the mass was performed which was reviewed at several different institutions, though it was considered indeterminate. A second transrectal biopsy of the periprostatic/seminal vesicle soft tissue mass was performed, which was reviewed at our institution and found to be a grade 4 (of 4) epithelioid angiosarcoma. Immunohistochemical stains showed the tumor cells reacted strongly and diffusely with antibodies to CD31 and vimentin, but did not react to antibodies to keratin (Cam 5.2, 7, 20 and wide spectrum), prostate specific antigen, actin, desmin, melanin A, S-100, CD117 (C-kit), synaptophysin, and chromogranin, supporting the diagnosis.\nThe patient was referred to our institution for further evaluation and management. Digital rectal examination revealed a normal anal sphincter tone and a large, firm, fixed mass in the left lateral rectal area without apparent rectal mucosal involvement. Magnetic resonance imaging (MRI) was performed, which showed an infiltrating soft tissue mass in the left lower pelvis involving the left seminal vesicle, the base of the prostate and the left bladder wall (). The mass extended laterally resulting in effacement of the left obturator internus muscle. A fatty soft tissue plane separated the mass from the adjacent left anterior rectal wall. A chest CT showed a few small indeterminate pulmonary nodules and a small calcified granuloma within the left lower lobe. A colonoscopy showed no evidence of rectal invasion. Given the presence of locally advanced tumor and the high risk for micrometastatic disease, the multidisciplinary team consisting of urology, medical oncology, and radiation oncology physicians recommended multimodality therapy consisting of neoadjuvant chemotherapy and radiotherapy followed by potential surgical resection.\nThe patient received two cycles of neoadjuvant IMAP chemotherapy, consisting of ifosfamide (2500 mg/m2 IV days 1-2), Adriamycin (40 mg/m2 IV day 2), mitomycin (4 mg/m2 IV day 2), cisplatin (60 mg/m2 IV day 2), and mesna (1500 mg/m2 IV and 2500 mg/m2 per days 1-2.) Repeat imaging following IMAP showed that the soft tissue mass in the left pelvis slightly decreased in size from 5.6×5.1 cm to 4.3×4.0 cm. The patient then received external beam radiation therapy () consisting of 50 Gray in 25 fractions delivered daily over 5 weeks with 2 cycles of concomitant MAP chemotherapy, consisting of mitomycin (8 mg/m2 IV), adriamycin (40 mg/m2 IV) and cisplatin (60 mg/m2 IV).\nFollowing a six-week recovery from preoperative chemoradiation, repeat imaging studies showed no significant change in the pelvic mass and no evidence of distant metastatic disease. He then proceeded to surgical resection with a radical prostatectomy, partial cystectomy, distal ureterectomy, bilateral pelvic lymph node dissection, and ureteroneocystostomy. Frozen section margins at the bladder and left pelvic sidewall were positive. Additional resection was performed and the margins were negative. An intraoperative electron radiation therapy boost (9 Gy) was given to the left pelvic sidewall as there was a concern for residual microscopic disease. Review of the surgical pathology demonstrated grade 4 (of 4) epithelioid angiosarcoma forming a 3.5×2.6×1.8 cm mass in soft tissue in the region of the left seminal vesicle (). The tumor involved the left seminal vesicle, infiltrated adjacent skeletal muscle, and extensively involved regional nerves and ganglia, but tumor did not extend into prostatic parenchyma. The final surgical margins were negative for tumor. Multiple left and right pelvic lymph nodes (external iliac, internal iliac, common iliac and obturator regions) were negative for tumor involvement.\nPost-operatively he had left thigh numbness that subsequently resolved. He developed a vesicourethral anastomotic leak which required prolonged (3 months) Foley catheter use; however, this completely resolved. He developed an abscess that was drained and resolved. The patient was then seen in regular follow up with serial imaging studies over the subsequent six years following surgery and he has not developed evidence of cancer recurrence.