(a).

	Histological features
Superficial myofibroblastoma   (SMF)	Usually moderate, sometimes hypocellularity   Fine and dense collagen in stroma   Small to medium-sized dilated vessels, often centrally located
Cellular angiofibroma,	Moderate cellularity   Wispy collagen stroma   Medium-sized vessels, often with hyalinized walls
Mammary type myofibroblastoma,	Moderate to hypercellularity   Thick collagen bundle in stroma, adipose tissues may be present   Blood vessels are not prominent
Angiomyofibroblastoma, (AMF)	Alternating zones of hyper- and hypocellularity.    Loose texture, contains mast cells in stroma, adipose tissues may be present   Small to medium-sized capillary-like vessels around which epithelioid stroma cells are clustered
Aggressive angiomyxoma   (AA)	Hypocellularity   Myxoid stroma, entrapped tissue may be present   Numerous blood vessels varying from small size to large size with thick muscular walls