Epididymal Nodule in an Adult

Specimen Type:

Epididymis

History:

A 39-year-old man presented with hard “lump” on the head of right epididymis encroaching on to the testicular tunica. At gross description, the lesion is firm and nodular, measuring 0.5 cm in diameter. Representative cross-sections were submitted.

Pathologic Features:

Sections show normal sperm producing testicular tubules, fibrous tunica and an exophytic (Figure 1), ulcerated lesion composed of small capillaries in an inflamed, non-descript stroma (Figures 2-3). Occasional loose, non-caseating granulomas are present at the base of the lesion. No epithelial lined structures or other specific pathology noted.

Differential Diagnosis:

  • Capillary hemangioma
  • Pyogenic granuloma
  • Sperm granuloma

Capillary hemangioma: Capillary hemangiomas usually appear during the first few years of life and are located in the skin or subcutaneous tissue. They are composed of a proliferation of capillary-size vessels lined by flattened endothelium. The term lobular hemangioma has been employed as a generic designation for a number of hemangiomas characterized by this architectural pattern, including capillary hemangioma of infancy, pyogenic granuloma, and epithelioid hemangioma.

Pyogenic granuloma: Pyogenic granuloma is a relatively common benign vascular lesion of the skin and mucosa whose exact cause is unknown. This misnamed entity is neither infectious nor granulomatous. The lesion usually occurs in children and young adults as a solitary glistening red papule or nodule that is prone to bleeding and ulceration. It typically evolves rapidly over a period of a few weeks, most often on the head, neck, extremities, and upper trunk . Aside from cutaneous and oral lesions, pyogenic granuloma has been reported throughout the gastrointestinal tract, the nasal mucosa, the larynx, and the conjunctiva and cornea.

Sperm granuloma: Sperm granuloma is an exuberant foreign body giant cell reaction to extravasated sperm and occurs in 42% of patients after vasectomy and 2.5% of routine autopsies. It appears as a solitary, or multiple, small, indurated nodules measuring up to 3 cm in diameter. Extravasated sperm are often present in large numbers, but are quickly engulfed by macrophages.

Diagnosis:

Pyogenic granuloma in the epididymis.

Key Features:

  • Firm, slightly pedunculated nodule, usually 0.5cm in diameter
  • Reactive vascularisation (common association with preexisting injury or irradiation)
  • Examples arising in gingival of pregnant women (granuloma gravidum) are considered a separate subgroup, but are histologically indistinguishable
  • Reported in association with systemic retinoid therapy
  • Occasionally found in subcutaneous or intravascular locations
  • Occurs at any age, more common in children and young adults. Equally prevalent in males and females
  • Multiple satellite lesions occasionally develop near a primary pyogenic granuloma, usually after destruction of that lesion
  • Never been reported in the epididymis

References:

  1. Elder DE, Lever WF: Lever’s Histopathology of the Skin, 9 th edition. Lippincott Williams & Wilkins, 2004.
  2. Barnhill R: Textbook of Dermatopathology, 2 nd edition. McGraw-Hill Professional, 2004.
  3. Weedon D: Skin Pathology, 2 nd edition. Churchill Livingstone, 2002.
  4. Bostwick DG, Eble JN: Urologic Surgical Pathology, Mosby-Year Book, Inc., 1997.