Angiomyofibroblastom

Angiomyofibroblastoma
of the ischiorectal fossa. On the axial T1-sequence the tumour presents as a well-defined hypointense mass in the ischiorectal fossa with significant mass effect to the closely attached pelvic diaphragm.
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Angiomyofibroblastoma
of the ischiorectal fossa. The tumour in the ischiorectal fossa shows significant enhancement. Due to the close relationship of the various anatomical compartments and the associated mass, the exact delineation of the pelvic diaphragm is obscured.
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Angiomyofibroblastoma
of the ischiorectal fossa. The tumour in the ischiorectal fossa shows significant enhancement. Due to the close relationship of the various anatomical compartments and the associated mass, the exact delineation of the pelvic diaphragm is obscured.
www.eurorad.org • CC by-nc-sa-4.0
Angiomyofibroblastoma
of the ischiorectal fossa. The mass presents with bright signal and a linear hypointense structure in between. Due to the close relationship of the various anatomical compartments and the mass, the exact delineation of the pelvic diaphragm is obscured.
www.eurorad.org • CC by-nc-sa-4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Angiomyofibroblastomas are benign mesenchymal neoplasms usually found in the pelvis or perineum especially the vulva.

Epidemiology

Angiomyofibroblastomas are uncommon tumors predominantly found in adult women usually between menarche and menopause. Approximately 10% of these tumors have been described in postmenopausal women. In men, they are rare .

Clinical presentation

The usual complaint is a slowly progressive well-defined painless mass .

Pathology

Angiomyofibroblastomas are well-circumscribed myofibroblastic lesions characterized by prominent stromal vessels surrounded by round to ovoid or spindle-shaped tumor cells .

Etiology

The etiology of angiomyofibroblastoma is unknown .

Location

Most angiomyofibroblastomas are found in the perineal region with most being located in the vulva or perineum followed by the vagina and uterine cervix. They can occur in other regions for example in the mediastinum or nasal cavity but only in very rare occasions .

Macroscopic appearance

Macroscopically angiomyofibroblastomas are well-demarcated lesions, they are not encapsulated and some might be pedunculated. They usually have a soft consistency and are of pink-tan color .

Microscopic appearance

The histological appearance of angiomyofibroblastomas is characterized by the following  features :

  • thin fibrous pseudocapsule
  • prominent thin-walled ectatic vessels in an edematous matrix
  • round to ovoid epithelioid or spindle-shaped tumor cells with eosinophilic cytoplasm
  • well-differentiated adipocytic components in about 10% of cases
  • degenerative nuclear atypia
  • rarely morphological overlap with aggressive angiomyxoma
Immunohistochemistry

Immunohistochemistry stains express vimentin and are usually positive for desmin, unless in postmenopausal women.   There is only a focal expression of smooth muscle actin (SMA) and muscle-specific actin (MSA). In addition tumor cells usually express estrogen receptor, progesterone receptor and occasionally CD34 .

Radiographic features

Angiomyofibroblastomas are usually solid well-demarcated vascularized lesions.

Ultrasound

There is some variability with respect to ultrasound findings. On one hand, angiomyofibroblastomas have been described as solid-cystic-appearing lesions with inhomogeneous echogenicity on the other hand homogeneous appearing lesions have also been described. Color Doppler imaging usually displays intralesional or peripheral vascularization .

MRI

Angiomyofibroblastomas apparently appear as solid well-circumscribed variably heterogeneous soft tissue masses .

Signal characteristics
  • T1: low to intermediate signal intensity
  • T2: heterogeneous mixed to high signal intensity
  • T1 C+ (Gd): intense enhancement with variable heterogenicity

Radiology report

The radiological report should include a description of the following:

  • location and size of the tumor
  • relation to other organs
  • relation to soft tissue structures structures

Treatment and prognosis

The main treatment is surgical excision.  Angiomyofibroblastomas are benign and have an excellent prognosis with local recurrences being reportedly rare even with marginal excision .

History and etymology

Angiomyofibroblastoma was initially described by Fletcher and colleagues in 1992 .

Differential diagnosis

Conditions with similar clinical presentation or appearance of angiomyofibroblastomas include :

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Angiomyofibroblastom:
Angiomyofibroblastom
der Fossa ischiorectalis
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