Lipomembranous fat necrosis in three cases of testicular torsion

To describe for the first time a lesion termed lipomembranous fat necrosis (LFN) in three patients with spermatic cord torsion.

We reviewed 386 testes and their epididymides and spermatic cords which had been removed for testicular infarction. For the three cases showing LFN, a battery of histochemical tests (including periodic acid-Schiff (PAS), orcein, Sudan black and Perls stains) was applied and clinical histories and laboratory data were also investigated. Findings were similar in the three specimens. The testes showed a central group of necrotic seminiferous tubules which were surrounded by granulation tissue consisting of macrophages, multinucleated giant cells, lymphocytes, plasma cells and fibrous connective tissue at the periphery of the lesion. The spermatic cord showed thrombosed veins surrounded by fat necrosis showing cystic cavities which were bounded by wavy hyaline membranes. These stained with Sudan black, PAS (before and after diastase digestion) and orcein and presented yellowish-green autofluorescence.

Lipomembranous fat necrosis of the spermatic cord is a distinctive entity which seems to be related to spermatic cord torsion and the differential diagnosis of which should be established with regard to the presence of parasites, sclerosing lipogranuloma and granuloma evoked by rupture of a testicular prosthesis.