Contributed by Edward D. Plowey, MD, Jyoti P. Balani, MD, Uma N. M. Rao, MD and Rajiv Dhir, MD
Published on line in March 2006
The patient is an 80-year-old man who presented with the chief complaint of right hemi-scrotal swelling following a history of prostatic adenocarcinoma diagnosed 8 years earlier. The prostate cancer was treated by a combination of radiation therapy and androgen deprivation therapy. Biochemical recurrence of prostatic adenocarcinoma had recently been documented prior to the onset of the swelling. Physical examination revealed a paratesticular mass that was clinically felt to be a benign hydrocele.
The patient's past medical history is significant for moderately-differentiated prostatic adenocarcinoma, Gleason score 3 + 3 = 6. The prostate cancer was diagnosed eight years ago by trans-rectal prostate needle biopsies performed at an outside institution following an elevated serum prostatic specific antigen (PSA) level (11.3 ng/ml). The patient, then at his early 70s, was started on 150 mg/day Casodex for a clinically staged T2a prostatic adenocarcinoma with a prostate gland volume of 71cc. His PSA level fell to 1.9 ng/ml following hormone therapy. The patient then received external-beam radiation for 42 cycles, with a minimum tumor dose of 7740 cGy. The last dose of radiation therapy was given in late 2000. The patient's PSA decreased to as low as 0.6 ng/ml post-treatment. The patient was found to have biochemical recurrence of prostatic adenocarcinoma, serum PSA level of 1.6 ng/ml, on routine follow-up in the summer of 2005. Shortly after, the patient complained of right hemi-scrotal swelling and the right paratesticular mass was noted.
The patient was immediately referred for ultrasonography of the paratesticular lesion that revealed abnormal enlargement of the right epididymis (3.02 X 2.14 X 2.2 cm) by a hypervascular mass (Fig. 1A and 1B). The radiologic differential diagnosis was infection versus tumor. There was also a right-sided hydrocele and slight heterogeneity of the right testis; however, no definite testicular mass was identified. The left scrotal contents were unremarkable. The patient was placed on antibiotic therapy with ciprofloxacin for six weeks to rule out an infectious etiology. Followup testicular ultrasound in the fall of 2005 revealed no change in the size or appearance of the lesion, thus favoring a tumor diagnosis.
The patient subsequently underwent scrotal exploration for a clinical suspicion of adenomatoid tumor of the epididymis. The mass was identified and needle biopsies performed for a frozen section - evaluation revealed hypocellular cores with irregular groups of atypical cells. The morphologic features were suspicious for sarcoma. The differential diagnosis was an adenomatoid tumor. No evidence of prostatic adenocarcinoma was seen. Right orchiectomy was performed based on this differential diagnosis.
Gross examination revealed a 3 cm, moderately-circumscribed, roughly nodular tumor superior to the epididymis and testis (Fig. 2). The tumor, on cut section, was comprised of red-brown, fleshy tissue with extensive hemorrhage and an irregular pushing border. Histologically, the tumor was comprised of areas with irregular, haphazard, freely anastomosing vascular channels (Fig. 3A, 3B and 3C). The vascular channels were lined by atypical endothelial cells with crowding, nuclear pleomorphism, irregular nuclear membranes, and clumped chromatin. Highly vascular regions blended with areas of tumor that were more epithelioid with higher proliferative index as demonstrated by Ki67 immunostain (Fig. 4). Tumor cells exhibited strong immunoreactivity for CD31 (Fig 5), CD34, and Ulex Europaeus Lectin; immunostains for prostatic specific antigen and cytokeratins were negative. The tumor was bulging into and focally through the wall of a pampiniform plexus vein. The tumor was observed to be on the luminal side of venous walls of the pampiniform plexus, in many areas, replacing the normal endothelium. Extensive tumor necrosis was noted. The histomorphologic features were diagnostic of an angiosarcoma, most-likely radiation-associated. All examined surgical margins of resection were free of tumor.
The patient was without complaints and without evidence of local tumor recurrence on 3-month followup. Baseline staging CT was performed and showed no evidence of metastasis.