Histologically, they consist of a proliferation of tightly packed slender spindle cells lacking pigment. Immunohistochemical stains may be useful in making the diagnosis, as leiomyomas express smooth muscle–related antigens. By light and transmission electron microscopy, these tumors sometimes exhibit both myogenic and neurogenic features. In such cases, the term mesectodermal leiomyoma is employed.

Trauma

The uveal tract is frequently involved in cases of ocular trauma. Prolapse of uveal tissue through a perforating ocular injury is a common association. Rupture of the choroid may occur as the result of a blunt or penetrating injury. The pattern of the rupture most frequently appears as semicircular lines circumscribing the optic nerve head in the peripapillary region. If the macula is involved, the prognosis for vision recovery is guarded. Subretinal neovascularization can occur as a late complication. More severe injury may cause rupture of both the choroid and the retina, a condition termed chorioretinitis sclopetaria.

Choroidal detachment, either localized or diffuse, may occur after traumatic globe rupture or surgery. Serous or hemorrhagic fluid accumulates in the suprachoroidal space between the choroid and the sclera. Depending on the etiology, the fluid may spontaneously resorb, allowing for reattachment of the choroid. In other cases, surgical drainage of the fluid may be required.