Benign peripheral nerve sheath tumors (neurofibromas) of the lacrimal gland

Two patients, a 43-year-old woman and a 62-year-old man, developed benign peripheral nerve sheath tumors (neurofibromas) of the lacrimal gland, in the former case of the deep orbital lobe, and in the latter of the palpebral lobe. A neurogenic tumor was not seriously considered clinically in either case, because of the paucity of previous reports on the occurrence of neural tumors in the lacrimal fossa region. Instead, in the first case a benign mixed tumor was considered the most likely clinical diagnosis, whereas in the second the coexistence of a swelling in the parotid gland raised the possibilities of a lymphoid tumor or a leukemia. Due to unusual light microscopic features, transmission electron microscopy was required to secure unequivocal diagnoses. In the orbital lobe tumor, an encapsulated spindle cell proliferation without nuclear palisading but with focal areas of myxoid change suggested either a cellular benign mixed tumor or a schwannoma. The palpebral lobe lesion displayed a myxoid spindle cell proliferation that had splayed apart the ducts and acinae of the lacrimal gland, to impart the overall appearance of a benign mixed tumor. The ducts, however, were multilaminar rather than possessing the usual double cellular layer seen in classical benign mixed tumors, and the glandular units contained zymogen granules, which are typically not seen in benign mixed tumors. Electron microscopy disclosed in both lesions the presence of interrupted basement membrane material partially surrounding the tumor cells, long spacing collagen (banded basement membrane material), and poorly developed desmosomes, features compatible with a neural tumor. Neither myofilaments, tonofilaments, nor ductal-type granules sometimes observed in benign mixed tumors were discovered. The tumor cells in these cases therefore failed to demonstrate clear-cut Schwann cell characteristics (eg, continuous basement membranes, pseudo-mesaxons, tangles of cell processes), and more closely resembled perineural cells that have been described in ultrastructural studies of peripheral nerve tumors including neurofibromas of other sites.

Mucoepidermoid carcinoma of the palpebral mucocutaneous junction. A clinical, light microscopic and electron microscopic study of an unusual tubular variant

An 81-year-old man developed a left lower lid lesion. The lid margin was red, thickened, and indurated with foci of ulceration and telangiectasia on the palpebral conjunctiva. The initial clinical impression was either a chalazion or sebaceous carcinoma, and an incisional biopsy was performed. By light and electron microscopy, the tumor demonstrated infiltrating cords of cells with an admixture of epidermoid and mucus-secreting elements arranged in a distinctive elongated tubular fashion. The involved lid was resected and reconstructed by a Hughes' tarso-conjunctival graft with marsupialization of the canaliculus. No recurrence has been encountered after a year. Mucoepidermoid carcinoma of the conjunctiva is a rare, locally aggressive neoplasm characterized in all seven previously reported cases by recurrence within 6 months, and a high incidence of intraocular or orbital invasion.

Epibulbar subconjunctival fibroma. A tumor possibly arising from Tenon's capsule

A fibroma, a benign neoplasm arising from the periorbita or tendon sheaths, is described in a 74-year-old woman as an indolent, lobular tumor situated in the episcleral and subconjunctival connective tissues with superior limbal fixation. Because most fibromas arise from tendon sheaths or fascial planes, we speculate that our lesion arose from Tenon's capsule. The rarity of periocular fibroma is documented by a review of the modern ophthalmic literature. Histopathologically, the tumor was composed of a paucicellular population of fibroblasts, sometimes displaying hyperchromatic nuclei and widely separated by abundant broad bundles of collagen. Mast cells were infrequently dispersed in the lesion. A wide local excision was performed, and no recurrence has developed during an 18-month follow-up period.

Elastofibroma oculi

A 69-year-old woman had a placoid lesion extending from the temporal limbus with a ptyergioid head to involve extensively the temporal epibulbar conjunctiva, the superolateral and inferolateral fornices, and the lateral canthus. It was composed of thickened bundles of collagen, scattered islands of adipose tissue, and abundant refractile linear elastinophilic structures. Electron microscopy confirmed that the elastinophilic structures were mature elastic fibers embedded within markedly thickened bundles of collagen. This lesion resembles elastofibromas that occur in a subscapular location. Elastofibroma oculi is distinguishable from the more common pterygium and pinguecula by the sparing of the immediate subepithelial zone of the conjunctiva, which is preferentially involved by these other lesions, and by failure to exhibit ultrastructurally microfibrillar aggregates and dystrophic elastic fibers. Both the elastic fibers and thickened bundles of collagen in the elastofibroma are presumed to have arisen from activated fibroblasts.

[Effects of intraseptal microinjection of 6-hydroxydopamine upon the time discrimination behavior in rats]

An intraseptal 6-hydroxydopamine (6-OHDA) injection technique was used in order to examine the specific functions of the catecholamine (CA) neurons in the septal area upon the time discrimination behavior. After some preliminary CRF trainings of 5 days, 21 rats of Wistar strain were divided into 3 homogeneous groups according to their performance on the last session. 6-OHDA group (n = 6) was stereotaxically injected into the medial septal area with 8 micrograms of 6-OHDA in 0.9% saline solution containing 0.1% ascorbic acid. Ascorbic acid group (n = 5) was injected with only ascorbic acid solution and the remaining group (n = 10) received no treatments. Following the 6 recovery days and the next CRF trainings of 5 days, all subjects were exposed to a DRLL 20/LH 36 training for 30 min per day and consecutively for 30 days. As the results of these trainings, 6-OHDA group showed significantly better performance and less acceleration of operant responding just after incorrect (non-rewarded) responses as compared with other control groups in the early 10 sessions of the trainings. These findings suggested that the acquisition of time discrimination behavior was facilitated in the 6-OHDA group which was hardly affected by the emotional disturbance just after non-rewards. Therefore the authors consider that the emotional disturbance caused by non-rewards impairs the inhibition of operant responding by mediating the CA neurons in the septal area.

Anti-atherosclerotic action of elastase--with special reference to its effect on elastic fibres

In order to determine the anti-atherosclerotic action of elastase, the aortas from four groups of rats--group N fed a normal diet, group D fed an atherogenic diet with vitamin D2, group N + Ela fed a normal diet with elastase, and group D + Ela fed an atherogenic diet and vitamin D2 with elastase--were studied histologically after 3, 6, 9, and 12 weeks of feeding. Group D displayed a remarkable atheromatous change, while the change was insignificant in group D + Ela. The histopathological findings in group D consisted of marked rarefaction, fat deposition, and atheroma in the subendothelial tissue and tunica intima; Van Gieson's staining revealed a conspicuous decrease in elastic fibres, and the remaining elastic fibres had such abnormalities as a tortuous course, bends, and fissures. For group D + Ela, on the other hand, there were few foam cells in the subendothelial tissue and tunica intima and much less marked rarefaction of interstice and fat deposition. Further, the arrangement of elastic fibres was only slightly disordered, and the decreases in elastic fibres and their fissures were moderate. In sharp contrast to group D. which showed marked calcium deposition, group D + Ela was found to have low calcium deposition. No macroscopic and histopathologic abnormalities were found in groups N and N + Ela. Elastase had an inhibitory effect on experimental atherosclerosis in the rat and also regulated the degradation and biosynthesis of elastin, which resulted in the regeneration of elastic fibres.

Opportunistic toxoplasmic retinochoroiditis following chemotherapy for systemic lymphoma. A light and electron microscopic study

After a prolonged period of chemotherapy for a disseminated nodular lymphoma, a 51-year-old woman developed a white lesion in the left macular region, in the absence of any overt lymphomatous disease elsewhere. The initial retinal diagnosis was nonetheless a lymphomatous infiltrate. Due to her severely immunocompromised state, the patient developed pneumonia and died. The involved left eye was examined postmortem by light and electron microscopy. The retinal lesion was discovered to be caused by infection with Toxoplasma gondii, which on postmortem evaluation was also found in the brain together with subclinical lymphomatous disease and multifocal leucoencelphalopathy. Many viable and intact cysts were observed floating within the necrotic retina as well as lodged within recognizable retinal cells. Most of the organisms were encysted bradyzoites, although a rare tachyzoite was discovered in the extracellular space. Unusual features examined ultrastructurally were a preretinal membrane formed exclusively by glial cells, residual proliferating glial cells within the retina that were frequently related to surviving capillaries, and a multilaminar spindle cell placoid proliferation of pigment epithelial cells, assuming almost pseudo-sarcomatous proportions. Banded extracellular membrane material was focally observed between the proliferating pigment epithelial cells. No neoplastic lymphoreticular cells were discovered within the choroid, but a curious feature was the production of basement membranes by the surviving choroidal melanocytes. Toxoplasmosis should therefore be considered along with fungi and viruses in the differential diagnosis of white retinal lesions appearing in immunocompromised patients.

Cryotherapy for intraepithelial conjunctival melanocytic proliferations. Ultrastructural effects

A double freeze-thaw cryoapplication to the conjunctiva was used to treat the flat intraepithelial proliferation of atypical melanocytes in five patients. Electron microscopy of six paired biopsy specimens taken before and after cryotherapy showed in all specimens rupture of plasmalemmas of intraepithelial melanocytes and release of cytoplasmic debris into the intercellular space. In four patients the plasmalemmas of the squamous cells (keratinocytes) generally remained intact after nitrous oxide treatment (temperatures reaching -20 degrees C by thermocouple monitoring), but these cells frequently displayed dissolution of intercellular desmosomes and hemidesmosomal contacts with the basement membrane. In one patient treated with liquid nitrogen, both the squamous cells and the melanocytes were irreversibly damaged at temperatures of -40 degrees C. These ultrastructural data establish that there is a selective sensitivity of atypical intraepithelial conjunctival melanocytes to freezing at temperatures below -20 degrees C.

Malignant melanoma of the iris after 30 years

We report a case of a spindle cell malignant melanoma of the iris that was excised locally in 1952, only to become clinically evident again 25 years later. The tumor exhibited unusually slow, compact growth, with local infiltration into the ciliary body and dispersion of tumor cells into the angle structures and onto the posterior cornea. No extraocular dissemination was evident. Histologically, the cells in the specimens taken in 1952, 1978, and 1981 had remarkably similar morphological findings. The patient has had no recurrences 12 months after enucleation.

The ultrastructure of an IOL "cocoon membrane"

A white cocoon membrane emanating from an inferotemporal focus in the iris stroma totally ensheathed a Binkhorst four-loop iris plane lens 18 months after implantation. The membrane was removed and studied by scanning (SEM) and transmission (TEM) electron microscopy. By SEM the external surface of the membrane was characterized by a fibrillar meshwork, with only an occasional scattered spindle-shaped or rounded inflammatory cell occupying the surface. One-micron plastic sections revealed both spindle and polyhedral heavily pigmented cells in the outer aspect of the membrane, and compressed elongated nonpigmented spindle cells scattered throughout the central portions. By TEM cells clinging to the outermost aspects were bipolar iris stromal melanocytes with small melanosomes, inactive fibroblasts, or histiocytes with cytoplasmic ruffles. The larger rounded pigmented cells in the superficial region were viable or degenerated iris pigment epithelial cells or macrophages. Most of the substance of the membrane was composed of collagen fibrils 100-500 A in diameter with and without 640 A periodicity; these fibrils were generally oriented parallel to the spindle cells but did not display distinct bundling or a lamellar architecture. The spindle cells in the center of the lesion were active fibroblasts with abundant rough-surfaced endoplasmic reticulum and scattered actin myofilaments; they contained rare small and large melanin granules indicative of phagocytosis. It has been concluded that the membrane was produced predominantly by iris stromal fibroblasts probably activated by the haptics of the IOL or McCanell suture.

Primary infiltrating signet ring carcinoma of the eyelids

A 61-year old man presented with a five-year history of a swelling initially developing in his right lower lid that progressed to involve the lateral canthal skin and eventually the upper lid and anterior orbit. He was discovered to have an infiltrating, poorly differentiated, mucin-producing carcinoma. Systemic work-up failed to disclose a visceral malignancy, and it was concluded that his tumor was primary in the lids, arising from an adnexal sweat gland. Three other reports in the literature also share almost identical clinical and pathologic features, in that all of the earlier reports dealt with middle-aged or elderly men who had diffusely indurated lids. Histopathologically, the tumor cells grow diffusely in a sclerotic stroma, and resemble the "histiocytoid" variant of metastatic breast carcinoma to the lids in women. Ultrastructural studies in our case point toward an apocrine origin, although earlier authors have favored an eccrine origin. Despite its indolent clinical course, the tumor is capable of producing regional and distant metastases on long-term follow-up. Complete local excision, possibly necessitating radical surgery, is probably the preferred method of treatment, but local radiotherapy may have a beneficial effect in retarding spread of the disease.

Perfluoro-n-butane. A gas for a maximum duration retinal tamponade

The behavior of the gas perfluoro-n-butane (C4F10) in the rabbit vitreous suggests that the gas might be useful as a long-term intravitreal tamponade in retinal detachment surgery. Perfluoro-n-butane was found to expand more and remain in the eye longer than any gas previously reported. A 0.3-mL bubble expanded five times and displaced the entire rabbit vitreous in three days. The volume of the bubble began to shrink after one week, but still filled more than half the eye at three weeks. The time for total disappearance was more than three months.

Metastatic carcinoma masquerading as scleritis

A 36-year-old white man abruptly developed painless visual loss in his left eye. Fundoscopic evaluation revealed a shallow left superotemporal retinal detachment with an underlying yellowish choroidal infiltrate. Fluorescein angiography disclosed indistinct choroidal leakage, and both B-scan ultrasonography and computed tomography demonstrated superotemporal thickening of the choroid and the sclera. The patient was diagnosed clinically as having a scleritis and an associated exudative retinal detachment. He was placed on a several months' course of systemic prednisone, and despite this regimen, his condition worsened with the appearance of severe pain, proptosis and displacement of the eye, glaucoma, and intense episcleral and scleral injection. The eye was enucleated and displayed externally a massively thickened sclera superotemporally. Light microscopic evaluation of the enucleated globe revealed an extensively necrotic tumor growing diffusely within the choroid; infiltrating viable tumor cells were discovered within the sclera and episclera. The tumor cells had the characteristics of a well-differentiated, mucin-producing adenocarcinoma. Electron microscopic studies demonstrated lumen-forming tumor cells with apical villi, cytoplasmic pseudolumens, pools of cytoplasmic glycogen, and multiple types of inclusions, including mucin, lipid, and electron-dense secretory granules similar to those in pulmonary Clara cells. These findings were consistent with a bronchiolo-alveolar carcinoma. The patient subsequently developed bilateral reticulo-nodular pulmonary infiltrates, also typical of this tumor. The unusual clinical features of this case of "malignant scleritis" are discussed in light of the final diagnosis.

Human sympathetic ophthalmia. An analysis of the inflammatory infiltrate by hybridoma-monoclonal antibodies, immunochemistry, and correlative electron microscopy

A case of human sympathetic ophthalmia, enucleated after surgical trauma, was studied by means of hybridoma-derived monoclonal antibodies, histochemistry, and transmission electron microscopy. The choroidal infiltrate was composed predominantly of T-lymphocytes of the suppressor/cytotoxic subset (OKT8+); only 5% of the cells were immunoglobulin-producing B-lymphocytes (kappa or lambda light chain positive), thereby explaining the well-known paucity of plasma cells in the infiltrate. The epithelioid cells and phagocytic histiocytes in the choroid were la+ and OKM1+, antigenic determinants specific for bone marrow-derived monocytes, and their cytoplasms exhibited histochemical reactivity for alpha-1-antichymotrypsin and lysozyme. Ultrastructurally, the choroidal epithelioid cells contained single melanin granules in the cytoplasm, but these were membrane-bound and frequently associated with lysosomal material, features militating against these cells being transformed choroidal melanocytes. By means of immunologic and ultrastructural analysis, the Dalen-Fuchs nodules were found to be composed of a mixture of histiocytes (la+ and OKM1+) and depigmented retinal pigment epithelial cells (la- and OKM1-); the latter cells focally formed desmosomes and displayed inclusions of lipofuscin. Scattered within the Dalen-Fuchs nodules were small numbers of T-lymphocytes of the suppressor/cytotoxic subset. We have concluded that the uveitis and retinal pigment epithelial changes are mediated by a T-cell, delayed hypersensitivity pathogenetic mechanism (cell-mediated immunity), possibly directed at surface membrane antigens that may be shared by photoreceptors, retinal pigment epithelial cells, and choroidal melanocytes.

Elastodysplasia and elastodystrophy as the pathologic bases of ocular pterygia and pinguecula

Specimens of normal conjunctiva from three adult patients were examined by electron microscopy, which revealed normal elastogenesis in the substantia propria, but more prominently, in the episcleral tissues. Ultrastructural examination of eight pterygia and three pinguecula also disclosed evidence of elastogenesis, but in these lesions the morphogenetic sequence of fiber formation was distorted, and the elastic fibers were abnormal. The zone of hyalinization of the substantia propria immediately beneath the epithelium was the only site that manifested clear-cut evidence of collagen degeneration, which assumed the forms of effacement of the longitudinal periodicity of the collagen fibers, and of microfibrillar unfurling of the ends of the collagen fibers. Fibroblastic activity and elastic fiber formation were inconspicuous in this region. Beneath the hyalinized zone were collections of eosinophilic granular material. This material was shown ultrastructurally to be composed of excessive numbers of hollow-centered microfibrils (an elastic fiber precursor), with a tendency to clump centrally in the larger aggregated sheets and to acquire electron-dense inclusions. Numerous fibroblasts were found within this material. Finally, the elastotic fibers of light microscopy represented an abnormal maturational phase of elastic fiber production. These abnormal elastic fibers had microfibrils at their peripheries, but numerous electron-dense inclusions were associated with focal zones of amorphous elastin deposition. Occasionally histiocytes appeared to be engulfing these abnormal fibers. We have concluded that a large component of pinguecula and pterygia is the result of newly synthesized elastic fiber precursors and abnormal maturational forms of elastic fibers (elastodysplasia) that undergo secondary degeneration (elastodystrophy). These structures are presumed to be elaborated by actinically damaged fibroblasts of the substantia propria.

Lysozyme in human gastric carcinoma: a retrospective immunohistochemical study

A total of 171 gastric carcinomas comprising 69 advanced cancers and 102 early cancers were examined immunohistochemically for lysozyme. Tumour cells containing lysozyme were detected in 65 cases or 38% of the 171 gastric cancer cases. The incidence of these cells did not differ remarkably by histological type and infiltrative growth of gastric carcinoma. Of the foregoing 65 cases, two well-differentiated adenocarcinomas and three signet ring cell carcinomas had numerous lysozyme-containing tumour cells, 13 had many argentaffin or argyrophil cells, and 40 had various amounts of several types of mucin. In addition, tumour cells containing both lysozyme and mucin could be identified. No correlation could be observed between lysozyme immunoreactivity in the tumour cells and cellular infiltration of granulocytes or macrophages around the tumour. The lysozyme appeared to be produced by tumour cells. The two year survival rates indicate a tendency for advanced gastric cancers containing lysozyme to have a poor prognosis.

Selection of xenon gas for rapidly disappearing retinal tamponade

A gas that rapidly disappears from the vitreous may be of value in the treatment of retinal detachment. Xenon, argon, helium, carbon dioxide, and nitrous oxide were injected into the eyes of animal models to measure their disappearance times. Both Ar and He behaved much like air. The rapid disappearance of Co2 and N2O caused a profound hypotension. The gas with the most promising characteristics was Xe: 88% disappeared in three hours. The gas was replaced by aqueous as rapidly as it went into solution, so that the hypotensive effect was small.

Argyrophil cells in early gastric carcinoma: an immunohistochemical and ultrastructural study

Eighteen argyrophil cell carcinomas in 101 early gastric carcinomas were explained histologically, ultrastructurally, and immunohistochemically for polypeptides, carcinoembryonic antigen (CEA), lysozyme, and human chorionic gonadotrophin (hCG). Seven of these 18 tumors had gastrin, and two of seven tumors also contained somatostatin. In all of these 18 tumors CEA were demonstrated. Seven had lysozyme and five of seven tumors also contained gastrin; hCG were present in four of the 18 tumors and two of four tumors had gastrin, CA, mucin, and lysozyme simultaneously. Argentaffin cells were found in seven of 18 tumors. Of the above seven tumors containing gastrin, three had argentaffin cells. Ultrastructurally, several types of secretory granules were noted and tumor cells resembling D1- or P cells were present in nine of the 18 tumors. Macroscopically, many of the tumors showed IIc or IIc + III type. Histologically, the 18 tumors consisted of six well differentiated adenocarcinomas and 12 poorly differentiated adenocarcinomas including signet-ring cell carcinoma. These 12 tumors frequently developed in the stomach of young females. In view of our previous investigations, it was suggested that the IIc-type argyrophil cell carcinoma histologically showing poorly differentiated adenocarcinoma may be related to scirrhous carcinoma of the stomach.