Huge aneurysmal bone cyst secondary to giant cell tumor of the hand phalanx: a case report and related literature.

Background: Aneurysmal bone cyst (ABC) secondary to Giant Cell Tumor of bone (GCT) is a rare lesion, of which the incidence is about 0.011 to 0.053 per 100,000 every year. There are only a few previous case reports, and most of them occur in the spine, long bones or flat bones.

Case Presentation: We report one case of a patient who complained of "progressive enlargement of the mass on right-hand fifth finger for 5 years with ulceration for 6 months". After the imaging examination in our hospital, it was diagnosed as a "huge bone tumor on the proximal phalanx of the right-hand fifth finger", then wide excision and amputation of the fifth finger were made. The pathological examination diagnosed the mass as aneurysmal bone cyst secondary to giant cell tumor, 13 × 8 × 6 cm, with no local infiltration observed. No recurrence and metastasis occurred 18 months after the operation, and the patient recovered well.

Conclusion: In this report, we discuss the etiology, diagnosis, differentiation, and management of Aneurysmal bone Cyst secondary to Giant Cell Tumor of bone, and review previous case studies.