OBJECTIVE

To identify the structural organization of connective tissue and vascular bed of the external genitalia in primary massive localized lymphedema. To analyze a clinical case of the development of massive localized lymphedema of the external genitalia concurrent with primary lymphedema of the lower limb in a patient with a normal body mass index.

MATERIAL AND METHODS

The samples obtained by resection during volume reduction surgery were used to study the morphological features of the lymphatic bed and extracellular matrix of the scrotal skin and testicular dartos versus the samples without pathological changes. Biological samples were processed using standard techniques for histological, immunohistochemical and ultrastructural analyses. Lymphatic vessels were differentiated using the molecular lymphatic endothelial marker Podoplanin.

RESULTS

In lymphedema, there was an increase in the thickness of all scrotal skin layers, a decrease in the volumetric lymphatic vessel density, an expansion of the interstitial spaces, and a change in the structure of collagen fibers that were homogenized, loosened, and swollen and did not form a three-dimensional network. The testicular dartos exhibited intermuscular fibrosis, expansion of the interstitial spaces, and perivascular leukocytic infiltration.

CONCLUSION

Histological and immunohistochemical analyses revealed changes in the structural organization of the connective tissue matrix and lymphatic bed of the scrotal skin and testicular dartos in long-standing massive localized lymphedema. The feature of the described clinical case was the absence of signs of chronic inflammation and severe diffuse fibrosis in primary scrotal massive localized lymphedema in a patient with a normal body mass index.