aggressive angiomyxoma

Definition: Aggressive angiomyxoma (AA) is a distinctive, locally aggressive, fibromyxoid tumor of the pelvic and genital soft tissues.

Digital case

 JRC:1443 : Aggresive angiomyxoma of pelvic soft tissues.
 JRC:14570 : Aggresive angiomyxoma of peritoneum (ischiorectal fossa).

Images

 Deep (agressive) angiomyxoma. Young women vulvar tumor

• https://twitter.com/luishcruzc/status/758685476341415936
• https://twitter.com/UMichPath/status/1149362467828404224

AA is of unknown histogenesis but the cytologically bland spindled tumor cells, which surround characteristic variegated blood vessels, show fibroblastic or myofibroblastic features.

AA may be related to angiomyofibroblastoma (AMF), another cytologically bland fibromyxoid genital spindle cell tumor with variable myoid differentiation that does not, as a rule, recur.

The lesion formerly known as ’aggressive angiomyxoma’, which shows a predilection for the pelviperineal region of women, has been redesignated as deep ’aggressive’ angiomyxoma in order to de-emphasize the perception of aggression.

It is now appreciated that no more than 30% of these lesions recur locally and the majority of such recurrences are cured by one further re-excision.

Original perceptions concerning the more aggressive nature of this tumour type were likely to have been influenced by the inevitably skewed nature of consultation material.

Synopsis

 tumoral cells: wavy and fibrillar, spindled, stellate
 polygonal fibroblast-like CD34+ dendritic cells
 +/- nuclear and cytoplasmic staining for FXIIIa

Differential diagnosis

 angiomyofibroblastoma (AMF)

• AA and AMF are myxoid fibrohistiocytic tumors composed of CD34+ fibroblasts.
• Neoplastic CD34+ dendritic fibroblasts showed predominantly myxo-collagenous differentiation.
• Both AMF and AA are part of a morphologic and histogenetic continuum of myxofibrous and myoid tumors that may arise due to interactions between microvascular CD34+ fibroblasts and FXIIIa+ histiocytes.

Localization

 vulva, vagina (vulvovaginal aggressive angiomyxoma)
 pelvis soft tissues (aggresive angiomyxoma of pelvic soft tissues)
 hypodermis (hypodermal aggressive angiomyxoma)
 larynx (laryngeal aggressive angiomyxoma) (8868184)

Cytogenetics

 12q13-15 rearrangement with HMGA2 rearrangement and abnormal expression in aggressive angiomyxoma

• t(8;12) (11550285) : HMGA2 rearrangements
• t(1;12)(p32;q15) (17654722)
• t(12;21)(q15;q21.1) (18295664)

Molecular biology

 HMGA2 rearrangements in 33% of AAMs (17654722)

See also

 CD34+ primitive fibroblasts
 factor XIIIa+ dendritic histiocytes
 fibrovascular tumors
 fibrohistiocytic tumors
 myxoid soft tissue tumors
 microvascular unit (tissue responsible for stromal repair and remodeling and angiogenesis)
 CD34+ fibroblasts
 FXIIIa+ histiocytes (FXIIIa+ dendritic cells or FXIIIa+ dendritic histiocytes)

See also

 angiomyxomas

• superfical angiomyxoma (cutaneous myxoma)
• deep angiomyxoma

See also

 myxoid tumors

• angiomyxoid tumors

References

 Rawlinson NJ, West WW, Nelson M, Bridge JA. Aggressive angiomyxoma with t(12;21) and HMGA2 rearrangement: report of a case and review of the literature. Cancer Genet Cytogenet. 2008 Mar;181(2):119-24. PMID: 18295664

 The evolving classification of soft tissue tumours: an update based on the new WHO classification. Fletcher CD. Histopathology. 2006 Jan;48(1):3-12. PMID: 16359532