Tuesday, December 27, 2005

EVISCERATION AND EXENTERATIONS

Eviscerations and Exenterations:

Evisceration operations are used virtually exclusively for blind eyes that are painful. The operation removes the cornea and the ocular contents, leaving behind the scleral shell to retain a plastic implant. Evisceration specimens are usually processed like a complex surgical biopsy, blocking separately the cornea and as many blocks as required to study the ocular contents.

Example: EVISCERATION WITH PHTHISIS BULBI
Gross: The specimen, received in formalin and labeled, "intraocular contents OD," consists of an evisceration specimen which measures 15 x 15 x 14 mm in greatest dimensions. The external surface appears opaque and vascularized. The cornea is calcified. The rest of the ocular contents appear reddish-brown with dense calcification. After 1 week of decalcification the specimen was bisected. Cut section reveals corneal stromal scarring, peripheral anterior synechiae, a scarred and atrophic iris, a cyclitic membrane, a disorganized and collapsed uvea, total retinal detachment, fat droplets, and white tissue posteriorly (probably bone). The section was submitted in cassette A.


Micro: Sections of "intraocular contents OD" show cornea with hydropic epithelial changes, marked destruction and fragmentation of a calcified Bowman's layer with overlying extensive pannus formation, stromal edema, deep vascularization, scarring, and bone formation paracentral calcification below the epithelium. The Descemet's membrane is partially stripped away from the stroma. The endothelium is attenuated. The anterior chamber shows hemorrhage. The lens is calcified and shows marked cataractous changes. The iris is calcified atrophic and shows numerous clump cells. There is marked anterior synechiae that cover the anterior chamber angle. The ciliary body is atrophic. There is bone complete with marrow fat posteriorly and the retina is gliotic detached and focally calcified.

FINAL DIAGNOSIS: Intraocular contents, "OD" (evisceration)-- changes consistent with phthisis bulbi
-extensive calcification of cornea, iris, lens, retina and choroid
-retinal detachment and gliosis
-anterior synechiae with angle closure

Exenteration operations have been used primarily in ophthalmology to treat the following conditions: neoplasms of the eyelids that have either invaded the orbit or are too extensive to salvage (or replace) the eyelids: primary tumors of the orbit, secondary tumors of the orbit (e.g. extension of intraocular tumors), and severe inflammatory of infectious lesions (e.g. aspergillosis or mucormycosis). The eye cannot be salvaged in these cases because too much orbital tissue has been sacrificed in the operation to permit survival of the eye, or the primary process (whether neoplasm or infection) significantly involves the eye. As we have learned more concerning the survival of patients who have undergone exenterations of the orbit, the operation in ophthalmology for many conditions has lost favor. Such specimens currently are more likely to originate in the head and neck region, where the exenteration is combined with more extensive operations for neoplasms. Exenteration specimens are of major importance and each one needs to be discussed with the attending pathologist prior to operation, dissection and processing. The general procedure for these cases is to:

1. Obtain adequate history one day in advance

2. Inform the attend pathologist of the case one day in advance so that special solutions and arrangements can be made to collect the specimen.

3. Check to see if margins have been taken at frozen section or what margins in the exenteration specimen are pertinent. If margins exist then the specimen must be inked and sections taken for margins, (e.g. posterior, medial, lateral, superior and inferior margins as well as skin margins if necessary).

4. Provide adequate fixation if the attending pathologist does not want any tissue fresh for analysis (e.g. sebaceous carcinoma, research, melanoma, etc). This may involve removing the eye from the specimen.

5. Obtain adequate sections of the exenteration specimen to look for the pertinent pathologic findings (history and diagnosis dependent).


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