The patient went on to have a local resection.
Paraffin sections show densely hypercellular tissue fragments.These show a mixture of large mononuclear cells, multinucleated cells
and eosinophils. The mononuclear cells have reniform vesicular nuclei and a moderate amount of pale cytoplasm. Similar nuclear features are noted in the multinucleated cells. Eosinophils are dispersed as single cells as well as diffuse sheets intermingling with the mononuclear and multinucleated cells. No mitotic figures are identified and there is no necrosis. No bone tissue is included in the specimens submitted. The features are of Langerhans cell histiocytosis (eosinophilic granuloma).
feature images from this case