History: 32 yo female with left hip mass.
Solution: Primary tumoral calcinosis is a familial condition characterized by solitary or multiple painless, periarticular masses. Lesions primarily proliferate during the first 2 decades of life. The classic tumoral calcinosis lesions are characterized as lobular, densely calcified masses confined to the soft tissue, generally at the extensor surface of the joint in the anatomic distribution of a bursa. The most common locations of tumoral calcinosis in descending order are the hip, elbow, shoulder, foot, and wrist. At surgery, these lesions are commonly cystic and contain a white to pale yellow chalky material identified as calcium hydroxyapatite crystals with amorphous calcium carbonate and calcium phosphate. At histopathologic examination, epithelioid elements and multinucleated giant cells surround calcium granules. This information is from: RadioGraphics 2006;26:871-885. Here is what the aspirate and gross pathology of this case looked like.