Sclerosing lipogranuloma pathology

Introduction

Sclerosing lipogranuloma usually presents as a painless or slightly tender, indurated mass on the penis, scrotum, spermatic cord and perineum. It is typically due to injection or topical application of oil based substances (paraffin, silicone, oil or wax) for cosmetic or therapeutic use.

Histology of sclerosing lipogranuloma

In sclerosing lipogranuloma, the histopathology shows fat necrosis, histiocytes, giant cells with extensive fibrosis and hyalinization. There are polymorphous vacuoles of the foreign material and pseudocysts where there is more extensive accumulation of material (figures 1,2).

Figure 1

Figure 2

None are generally needed. Oil Red O for frozen tissue is positive but rarely used.

Differential diagnosis for lipogranuloma

Other diagnoses to be considered include:

• Liposarcoma — this is the most important differential to exclude. In liposarcoma, there are irregular adipocytes of variable sizes, presence of lipoblasts and usually no giant cells
• Lymphangioma — when lymphangiomas are treated with sclerotherapy, the distinction can be difficult. Instead of the pseudocysts seen in sclerosing lipogranuloma, lymphangiomas are made up of lymphatic spaces lined by endothelium.