Angiomyofibroblastoma is an uncommon benign

mesenchymal Mesenchyme () is a type of loosely organized animal embryonic connective tissue of undifferentiated cells that give rise to most tissues, such as skin, blood or bone. The interactions between mesenchyme and epithelium help to form nearly every ...

tumor. It occurs mostly in the vulvovaginal area of women, but can also be observed in men. The World Health Organization, 2020, reclassified these tumors as a specific type of tumor in the category of

fibroblastic and myofibroblastic tumors Fibroblastic and myofibroblastic tumors (FMTs) develop from the mesenchymal stem cells which differentiate into fibroblasts (the most common cell type in connective tissue) and/or the myocytes/ myoblasts that differentiate into muscle cells. F ...

. The gross features of AMFB are well-circumscribed. Usually, most tumors grow slowly, and patients do not feel pain. It also has low tendency for local recurrence.

Location

* In women **

Female genital tract The female reproductive system is made up of the internal and external sex organs that function in the reproduction of new offspring. In humans, the female reproductive system is immature at birth and develops to maturity at puberty to be ...

Vulva The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, vestibular bulbs, v ...

** Posterior perivesical space * In men **

Spermatic cord The spermatic cord is the cord-like structure in males formed by the vas deferens (''ductus deferens'') and surrounding tissue that runs from the deep inguinal ring down to each testicle. Its serosal covering, the tunica vaginalis, is an extens ...

Pathology

Microscopical examination shows abundant thin-walled blood vessels with hypocellular and hypercellular areas.

Immunohistochemistry

Almost all tumor cells have

immunoreactivity An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoassay ...

for both desmin and vimentin. It also express

estrogen receptor Estrogen receptors (ERs) are a group of proteins found inside cells. They are receptors that are activated by the hormone estrogen (17β-estradiol). Two classes of ER exist: nuclear estrogen receptors ( ERα and ERβ), which are members of th ...

s and/or

progesterone receptor The progesterone receptor (PR), also known as NR3C3 or nuclear receptor subfamily 3, group C, member 3, is a protein found inside cells. It is activated by the steroid hormone progesterone. In humans, PR is encoded by a single ''PGR'' gene res ...

s, but staining for

cytokeratin Cytokeratins are keratin proteins found in the intracytoplasmic cytoskeleton of epithelial tissue. They are an important component of intermediate filaments, which help cells resist mechanical stress. Expression of these cytokeratins within epi ...

is negative.

References

Soft tissue tumor {{Neoplasm-stub