[Tumoral calcinosis in a Sardinian patient mimicking hydatid disease: a case report].

The aim of this study is to report on a case of tumoral calcinosis (TC) mimicking hydatid cyst, which was diagnosed in a 51-year-old Caucasian woman of Sardinian origin. This lady presented with two symmetrical enlarging masses of soft tissue in the hips. The CT findings were suggestive of hydatid cysts. Grossly the two lesions appeared as unencapsulated firm, rubbery masses extending into the surrounding muscles. On cut surface the two specimens were multiloculated and contained either calcareous material or milky fluid. At histology the main findings were represented by multiple foci of amorphous calcified material bordered by proliferating macrophages, fibroblasts and multinucleated giant cells, separated by fibrous septa. The following characteristics are worth of note: the presentation in adulthood (late onset); the Caucasian race of the patient; the radiological appearances indicative of hydatid cyst; the aggressive clinicopathologic course, with multifocal involvement, rapid growth, infiltrative pattern. Histologically the TC exhibited the typical pattern of stage II according to Slavin's classification of disease.