Pseudogynecomastia due to neurofibromatosis--a light microscopic and ultrastructural study.

A six year old boy with bilateral breast enlargement was found to have a normal endocrine status. Resected tissue revealed the features of pseudogynecomastia due to a proliferation of fibrous tissue traversed by neuroid structures. Multinucleated giant cells were present within the fibrous tissue. Ultrastructural study revealed organized nerve elements in a collagenous stroma. The multinucleated giant cells appeared to be variants of the predominant stromal fibroblasts.