2020-10 / MARCH 9

52 year old male presented with chronic left epididymal pain and discomfort. On physical examination, the posterior portion of left epididymis felt “nodular”. The patient had a vasectomy more than 20 years ago. Images are from the epididymectomy specimen.


1. What is the correct diagnosis?

a. Metastatic prostate adenocarcinoma

b. Primary epididymal adenocarcinoma

c. Epididymitis nodosa with sperm granuloma

d. Tuberculosis and associated granulomas

1. Epididymitis nodosa with sperm granuloma

Epididymitis nodosa is an epididymal lesion analogous to vasitis nodosa. The epididymis typically demonstrates proliferating ductules and dilated tubules containing spermatozoa and mature sperm, haphazardly admixed with the normal epididymis tissue. Extravasation of sperm and sperm granulomas are commonly seen.
Epididymitis nodosa most commonly occurs in a post-vasectomy setting. It likely represents a regenerative effort following duct rupture, resulting from long-standing obstruction. Epididymitis nodosa is a benign lesion, and most patients are asymptomatic. However, it may present clinically with swelling, pain, and palpable nodularity in the region of epididymis.
Morphologically, the proliferating ductules and tubules may be confused with a malignant disease, particularly prostate adenocarcinoma. Indeed, when stained with AMACR and basal markers, these ductules often have prostate adenocarcinoma-like immunopattern (variable positive AMACR and loss of basal markers). However, reliable staining with PAX8 and negative staining for PSA and NKX3.1 will aid in distinguishing this lesion from prostate cancer.

Easley S, MacLennan G. Vasitis and Epididymitis Nodosa.
J Urol 2006; 175; 1502

Kezlarian BE, Cheng L, Gupta NS, Williamson SR. Vasitis Nodosa and Related Lesions: A Modern Immunohistochemical Staining Profile With Special Emphasis on Novel Diagnostic Dilemmas.
Hum Pathol 2018; , 73, 164-170

Yuan Gao
Memorial University of Newfoundland

Kiril Trpkov
University of Calgary


Epididymis, Sperm Granuloma, Epididymitis nodosa, Vasitis nodosa