Salivary Gland Choristoma of the Middle Ear

Abstract

While head and neck surgeons are accustomed to recognizing malignancies in their practices, developmental lesions are much less often encountered, and as such are not as likely to be included amongst other (more aggressive) differential diagnostic considerations. One such developmental lesion is the choristoma, defined as an architecturally normal arrangement of mature tissues found in a location not normally host to such tissues. Choristomas composed of recognizable salivary gland tissue may be found in a variety of locations including the middle ear. Middle ear salivary choristomas are distinctly unusual lesions and typically manifest as unilateral conductive hearing loss; while both adult and pediatric patients have been diagnosed with middle ear choristomas, most patients have been in the first two decades of life. As these are benign, nonprogressive lesions, treatment has been directed toward complete surgical excision whenever feasible, and biopsy for diagnosis with subsequent observation in the case of those lesions which are difficult to remove without endangering the facial nerve. There have been rare instances in which choristomas have been linked to the subsequent development of neoplasms, but in the main choristomas are regarded as self-limited developmental heterotopias.

Salivary Gland Choristoma of the Middle Ear and Review of the Literature

“…Most of choristomas are non-neoplastic lesions that do not require excision, unless recent growth is observed in adults or disproportionate growth occurs in childhood, but biopsy is needed for diagnosis [26]. We updated the review conducted by Rinaldo [27] and recent reports [28][29][30][31][32][33][34][35][36][37] of middle ear location.…”

“…Incomplete removal of salivary gland choristoma of the middle ear have not ever evolved to malignization, while monitoring of all reported cases has not been long enough to predict a possible malignancy. Rinaldo [27] points to a prominent benign behavior of ear's salivary gland choristomas in her literature review, including 4 malignant salivary gland tumors originating from the middle ear and speculatively evolving from choristomas.…”

Salivary gland choristoma of the middle ear

“…Opisana je povezanost tumora sa kongenitalnim malformacijama temporalne kosti, najčešće poremećenim razvojem slušnih koščica [4]. Pored salivamog, u temporalnoj kosti opisan je neuralni horistom sačinjen od glijalnog tkiva, kao i teratomi.…”

“…Klinička slika je nespecifična, karakterisana progresivnom nagluvošću provodnog tipa i recidivirajuéim zapaljenjem srednjeg uha ukoliko dode do infekcije koštanih zidova ili bubne opne oštećenih erozijom. Prema podacima iz dostupne literature salivami horistom je najčešće dijagnostikovan u 2. i 3. dekadi života [4,5].…”

“…Dijagnoza horistoma se zasniva na objektivnoj evaluaciji sluha, radiografijama teporalne kosti, a poseban značaj ima preoperativna ili postoperativna patohistološka analiza tumora [3,4]. Kim i saradnici [7] su opisali povezanost horistoma sa kongenitalnim malformacijama temporalne kosti, najčešće nedostatkom ili nepravilnostima slušnih koščica, a rjede mikrotiom ili atrezijom spoljnog slušnog kanala.…”