calcifying aponeurotic fibroma

WP

SPSC

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.

Associations

 disseminated adult-type fibrosarcoma (3760506)

Differential diagnosis

 in infants and children

• infantile myofibromatosis
• juvenile desmoid fibromatosis

 in adults

• palmar fibromatosis / plantar fibromatosis
• soft part chondroma
• malignant spindle cell tumors
  • monophasic fibrous-type fibrosarcoma

See also

 fibrous tumors
  fibromas

References

 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