Abstract
Tumoral calcinosis, first described by Inclan in 1943, is a rare disease of obscure etiology characterized by the formation of large, painless, juxta-articular calcified masses.
A 9-year-old boy was admitted to our hospital in 1984 with limited flexion of the left knee due to a mass at the anterior aspect. He had noticed skin eruptions at both knees and the right elbow one year previously. There was repeated chalky white discharge but no history of trauma at the locations.
Physical examination revealed several eruptions and painless masses at the extensor aspects of the knees and elbows. X-ray examination of the left knee showed a well-demarcated lobulated periarticular mass which was radiologically identified as calcification.
Laboratory examination showed normal serum levels of calcium, phosphorus and alkaline phosphatase. He didn't have renal disease, collagen disease or parasitic disease. Intense uptake of99mTc bone scan showed in the lesion. Excision of the mass at the left knee was performed. Calcification existed in subcutaneous fat and the connective tissues, but didn't involve bone, synovial membrane and muscles. Histologically, the lesions were characterized by microscopic lobules containing calcified mass which were separated by fibrous connective tissues. Electron microscopy showed needle-like crystal deposits both intracellularly, within mononuclear cells and extracellularly. In X-ray diffraction analysis there was a characteristic pattern of bone hydroxyapatite. Chemical analysis showed that the Ca/P ratio of the mineral supported the X-ray diffraction evidence.
