A Peculiar Form of Breast Fat Necrosis Simulating Hyaline Ring Granuloma (So-called Pulse Granuloma): A Rare Complication of Hyperparathyroidism.

Pulse granuloma is a rare, foreign body inflammatory reaction that occurs mainly in the oral cavity. It is exceedingly rare elsewhere, with only isolated cases described in the literature. We report the case of a 79-year-old woman with a history of normocalcemic hyperparathyroidism who presented to our hospital with a painful 4-cm lump in the upper quadrants-upper outer quadrant of her left breast. The clinical and radiological (BIRADS-5) findings were indicative of a malignant lesion. However, core needle biopsy revealed features simulating hyaline ring granuloma (pulse granuloma-like). A definitive diagnosis of lipomembranous fat necrosis was made by identifying its characteristic histomorphology. Histopathological study is essential to establish an exact diagnosis since clinical and imaging features may mimic breast carcinoma. To our knowledge, this is the first reported case of a hyaline ring granuloma-like in the breast, which may represent a peculiar form of degenerative change of lipomembranous fat necrosis.