Calcium pyrophosphate dihydrate crystal deposition disease mimicking malignant soft tissue tumor

Abstract

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease has multiple clinical features with variable courses creating several pitfalls in clinical diagnosis. There are number of reported cases mimicking malignant skeletal tumors such as chondrosarcoma. However, no case of CPPD disease with radiographic noncalcified soft tissue mass has been reported in the literature. Here we report a case of CPPD disease clinically mimicking soft tissue tumor with its magnetic resonance imaging appearance and histopathology.

Tophaceous calcium pyrophosphate dihydrate deposition disease of the knee mimicking an aggressive soft tissue tumour

“…Two cases have been previously reported in the knee joint 6 7. Only one of which was subtle on plain radiography,6 as was the case we present with also a similar clinical presentation and no history of trauma. In both cases, although plain radiographs did not demonstrate calcification in the mass, CT showed scattered focal areas of increased density compatible with calcification, demonstrating the potential value of carrying out CT.…”

“…Most previous cases of T-CPPD in the extremities were radiographically misdiagnosed as bone or soft tissue tumours 7 17. Two cases have been previously reported in the knee joint 6 7. Only one of which was subtle on plain radiography,6 as was the case we present with also a similar clinical presentation and no history of trauma.…”

“…In both cases, although plain radiographs did not demonstrate calcification in the mass, CT showed scattered focal areas of increased density compatible with calcification, demonstrating the potential value of carrying out CT. In the previous case, an excisional biopsy was performed and rhomboid-shaped, positively birefringent polarised light crystals compatible with CPPD were found 6. However, in our case the mass was much smaller and ultrasound guided needle biopsy was performed to confirm the histological diagnosis.…”

“…To our knowledge, there is only one case of T-CPPD without radiographic calcification in the existing literature 6. At the time of writing, only 30 cases in the joints of the extremities have been described in the literature.…”

Median Nerve and Ulnar Nerve Palsy Caused by Calcium Pyrophosphate Dihydrate Crystal Deposition Disease: Case Report

“…2,13 In this case, the mass lesion communicated with the distal radioulnar joint with severe degenerative changes. The mass penetrated through the capsule to the flexor tendon sheath.…”