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calcifying aponeurotic fibroma

Wednesday 18 January 2006

juvenile aponeurotic fibroma, Keasbey’s tumor; Calcifying Juvenile Aponeurotic Fibroma


Definition : Calcifying aponeurotic fibroma (or Keasbeay tumor) is a benign soft tissue neoplasm usually arising in the hand or wrist. The patient is most commonly a child or adolescent. The low power view shows fibroblastic cells arranged in a palisading fashion around foci of calcification.

Microscopy shows numerous fibroblastic cells proliferating around and in between calcified areas. The tumor may infiltrate surrounding fat or even muscle at the periphery; however, cytologic atypia is absent and mitotic activity is not increased. Recurrences are common. It does not metastasize.


- disseminated adult-type fibrosarcoma (3760506)

Differential diagnosis

- in infants and children

- in adults

See also

- fibrous tumors
-  fibromas


- Fetsch JF, Miettinen M. Calcifying aponeurotic fibroma: a clinicopathologic study of 22 cases arising in uncommon sites. Hum Pathol. 1998 Dec;29(12):1504-10. PMID: 9865839

- Sharma R, Punia RS, Sharma A, Marwah N. Juvenile (calcifying) aponeurotic fibroma of the neck. Pediatr Surg Int. 1998 Apr;13(4):295-6. PMID: 9553195