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Biomedical subjects

R L Font

Publications and source records attributed to R L Font.

At least 55 records · Page 3Linked to original sources
PubMed1995

Atypical mycobacterial infection of the orbit.

PURPOSE: To describe the clinical presentation and successful management of an orbital infection caused by Mycobacterium abscessus, a formerly unrecognized cause of orbital disease after penetrating trauma. METHODS: An orbital infection due to M. abscessus is described, and previously reported ocular and extraophthalmic infections caused by M. abscessus are reviewed. RESULTS: A 5-year-old boy had acute, painless visual loss shortly after being struck in his left lower eyelid with a fishing rod. Radiologic evaluation established a mass in the orbital apex. Initial biopsy and cultures of the apex mass were negative; however, additional orbital exploration and cultures demonstrated M. abscessus to be the causative organism. The orbital infection was treated successfully with long-term oral clarithromycin. Review of the literature on ocular/adnexal and soft tissue infections caused by atypical mycobacteria shows characteristic clinical and histopathologic features. CONCLUSIONS: To the authors' knowledge, only seven patients with atypical mycobacterial infections of the ocular adnexa have been reported. The patient reported in the current study illustrates the difficulty in establishing the preoperative diagnosis of atypical mycobacterial infections of the orbit. A chronic draining wound or a localized orbital abscess, after penetrating trauma, should alert the physician to the possibility of an M. abscessus infection. Clarithromycin, an oral macrolide antibiotic, appears to be the most effective medical therapy for these patients.

Administration, Oral↗
PubMed1995

Involvement of anterior chamber angle structures in disseminated histoplasmosis: report of three cases.

This study describes the involvement of anterior chamber (AC) angle structures in patients with disseminated histoplasmosis. The postmortem eyes from three patients (aged 33, 41, and 42 years, respectively) with disseminated histoplasmosis, two of whom had acquired immunodeficiency syndrome, were examined by light microscopy using hematoxylin-eosin, periodic acid-Schiff (PAS), and Gomori's methenamide silver (GMS) stains. Electron microscopy studies of the choroid were performed in one eye. Significant numbers of budding yeast forms of Histoplasma capsulatum measuring 2-5 microns in diameter were observed within the trabecular meshwork, Schlemm's canal and in the deep intrascleral plexuses. All eyes showed massive involvement of the choroidal vasculature, including the choriocapillaris. The organisms were observed freely as well as in small clusters within the cytoplasm of circulating monocytes. The vessels of the limbal conjunctiva (two eyes) and ciliary body (three eyes) contained many Histoplasma organisms. In one eye, several budding yeast were noted in an iris vessel and in occasional histiocytes within the ciliary muscle. Blood smears containing Histoplasma organisms were observed in two cases. None of the patients had an ophthalmologic examination prior to death. Involvement of the intravascular structures of the eye as well as the AC angle was observed in three patients with disseminated histoplasmosis. The fungus most likely reached the AC angle structures by direct hematogenous dissemination or via the aqueous humor by migration from vessels in the ciliary body and iris. An abnormal retrograde blood flow into the AC angle structures may have also played an important role. We suggested that the intraocular pressure be monitored in cases of suspected disseminated histoplasmosis to detect functional alterations indicative of a blockage in the outflow channels.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Cytologic evaluation of tumors of the orbit and ocular adnexa: an analysis of 84 cases studied by the "squash technique".

The cytologic features of 84 ophthalmic lesions were evaluated using the squash technique at the time of frozen section. Of the 84 lesions, 55 were located in the orbit, 17 in the lacrimal gland, and 12 in the ocular adnexa. Lymphoid lesions comprised most of the cases (n = 47). In this group, 34 cases were malignant lymphomas and 13 were lymphoid hyperplasias. Inflammatory/granulomatous lesions and mesenchymal tumors comprised eight cases each. Epithelial neoplasms of the soft tissues of the orbit, lacrimal gland and eyelid constituted 12 cases, of which eight were malignant and four were benign. A total of nine cases were due to neurogenic tumors, neuroendocrine neoplasms, and melanocytic tumors. The squash technique provides a means to evaluate the architectural and cytologic details of ophthalmic lesions, without the intrinsic problem of frozen section artifact. We believe that the squash technique is a simple, quick, and useful method for the diagnosis of orbital/adnexal lesions.

Eyelid Neoplasms↗
PubMed1994

Capnocytophaga keratitis. A clinicopathologic study of three patients, including electron microscopic observations.

BACKGROUND: Histopathologic studies of this unusual keratitis caused by Capnocytophaga species have not been reported previously. METHODS: The authors report the light microscopic and ultrastructural findings of three patients with a distinctive necrotizing keratitis caused by an anaerobic gram-negative bacillus. In three patients, ages 19, 81, and 91 years, a necrotizing stromal keratitis developed; two of these patients had a previous penetrating keratoplasty for pseudophakic bullous keratopathy. The first patient did not have ocular surgery previously and was treated initially for presumed Acanthamoeba keratitis. RESULTS: By light microscopy, all three keratectomy specimens were strikingly similar and showed a necrotizing and/or suppurative stromal keratitis displaying myriad slender, fusiform, gram-negative bacilli located anterior to Descemet's membrane and extending into the deep corneal stroma, assuming a "picket fence" appearance. Cultures of the cornea in case 1 grew Capnocytophaga ochracea. For the remaining two patients, a diagnosis presumptively was made based on characteristic histopathologic features. Results of electron microscopic examination showed numerous bacilli that were mostly extracellular; occasional organisms were phagocytosed by macrophages. CONCLUSION: The histopathologic features of Capnocytophaga keratitis are unique; therefore, a presumptive diagnosis can be made based on the morphology and location of the bacilli in the keratectomy specimens. To the authors' knowledge, this is the first study describing the typical histopathologic and electron microscopic findings of Capnocytophaga keratitis.

Adult↗
PubMed1994

Clear cell epithelial-myoepithelial carcinoma arising in pleomorphic adenoma of the lacrimal gland.

BACKGROUND: A 63-year-old man had an 8-year history of painless proptosis, which had noticeably increased over the last 2 months. A mass was palpable in the left lateral canthus. Computed tomographic studies showed a globular mass with small foci of calcification involving the lacrimal gland. After an incisional biopsy, a histologic diagnosis of clear cell epithelial-myoepithelial carcinoma was made and an orbital exenteration was performed. FINDINGS: Results of histologic examination of the mass showed a partially encapsulated, clear cell epithelial-myoepithelial carcinoma with an associated pleomorphic adenoma (benign mixed tumor). Immunohistochemical studies disclosed strong immunoreactivity to cytokeratin (AE1/AE3), epithelial membrane antigen, S-100 protein, and alpha-actin. CONCLUSION: Although a clear cell myoepithelial carcinoma rarely has been reported in association with a pleomorphic adenoma of the submandibular gland, to the authors' knowledge, this combination has never been reported in the lacrimal gland, nor has a clear cell epithelial-myoepithelial carcinoma ever been reported in this anatomic location. The differential diagnosis of lesions with prominent clear cells involving the lacrimal gland is extensive and includes clear cell variants of acinic cell carcinoma and oncocytoma, mucoepidermoid carcinoma, and others.

Adenocarcinoma, Clear Cell↗
PubMed1994

Melanotic schwannoma of the choroid. Immunohistochemistry and electron microscopic observations.

PURPOSE: The purpose of this article is to describe what is probably the first reported case of a melanotic schwannoma of the choroid and to discuss the clinical and histopathologic features that serve to differentiate this rare intraocular tumor from a malignant melanoma of the choroid. PATIENT AND METHODS: A 21-year-old woman underwent enucleation of the right eye for a slowly enlarging pigmented choroidal mass that was associated with ipsilateral blindness. The tumor was studied by light microscopy, immunohistochemistry, and electron microscopy. FINDINGS: The tumor was composed of fascicles and whorls of pigmented and nonpigmented plump spindle cells that had light microscopic features of a schwannoma. The tumor cells showed immunoreactivity to S-100 protein and HMB-45. Electron microscopy showed cytoplasmic processes surrounded by a continuous basement membrane and abundant extracellular collagen. The pigmented spindle-shaped cells contained melanosomes in different stages of melanogenesis. The findings were compatible with a melanotic schwannoma. CONCLUSION: Melanotic schwannoma has been reported in soft tissues, peripheral nerves, and in the orbit. To the authors' knowledge, this is the first report of a melanotic schwannoma of the choroid. This extremely rare pigmented choroidal tumor may be very difficult to differentiate clinically from choroidal melanoma.

Adult↗
PubMed1994

Paramyxovirus-like inclusions in an intradermal nevus from a healthy woman.

A healthy 52-year-old woman had an intradermal nevus removed from the right preauricular region. Histopathologic examination disclosed intranuclear and intracytoplasmic inclusions in many of the nevus cells. A basal-cell carcinoma, an additional intradermal nevus, and a fibrous papule of the nose were also excised, however, none of these lesions showed histologically similar inclusions within the lesions. Electron microscopic studies showed inclusions that were similar to those observed in cases of subacute sclerosing panencephalitis. Immunoperoxidase and polymerase chain reaction studies for the measles virus were performed, with negative results. The patient remains in good health 2 years after excision of the skin lesions.

Basal Cell Carcinoma↗
PubMed1994

kappa-Immunoglobulin corneal deposits associated with monoclonal gammopathy. Immunohistochemical and electron microscopic findings.

A 62-year-old man had a 1-year history of bilaterally decreased visual acuity associated with irregular, patchy, grayish-white stromal infiltrates involving both corneas. As visualized by light microscopy, the keratectomy specimen showed numerous homogeneous, eosinophilic deposits located mostly within keratocytes in the posterior one-third of the stroma. The deposits stained reddish-brown with Masson's trichrome but were periodic acid/Schiff-negative. As visualized by electron microscopy, the intracytoplasmic deposits were located within dilated cisternae of rough-surfaced endoplasmic reticulum of keratocytes and disclosed a 10-nm periodicity with a distinct lattice pattern. Immunoperoxidase strains confirmed that the deposits contained immunoglobulin (IgG-kappa). At 2 weeks following a histopathologic examination of the keratectomy specimen, serum protein analysis and immunoelectrophoresis with quantitation of immunoglobulins demonstrated an IgG-kappa monoclonal gammopathy. The abnormal corneal deposits may be the first clinical sign of a malignant lymphoproliferative process that may be associated with a monoclonal gammopathy.

Corneal Diseases↗
PubMed1993

Pathologic features and immunofluorescent antibody demonstration of ocular microsporidiosis (Encephalitozoon hellem) in seven patients with acquired immunodeficiency syndrome.

We studied the clinicopathologic features of seven patients with acquired immunodeficiency syndrome (AIDS) and ocular microsporidiosis. All patients had decreased levels of CD4-positive cells (mean, 26/ml3) and ocular symptoms; five had bilateral punctate epithelial keratopathy, one had intermittent red eyes with conjunctivitis, and one had red eyes only. Light and electron microscopy of corneal and conjunctival biopsy and cytologic specimens and intact globes disclosed microsporidia belonging to the genus Encephalitozoon. Because E. cuniculi and E. hellem, the two species of the Encephalitozoon genus, are morphologically identical, an immunofluorescent antibody technique was used for species identification. In all seven patients, the agent was identified as E. hellem. Pathologic examination of globes obtained after autopsy disclosed E. hellem infection to be restricted to the corneal and conjunctival epithelium. We studied methods for the routine diagnosis of ocular microsporidiosis in patients with AIDS, including the role of immunofluorescent antibody staining.

AIDS-Related Opportunistic Infections↗
PubMed1993

Infectious crystalline keratopathy. The role of bacterial exopolysaccharide.

OBJECTIVES: Infectious crystalline keratopathy is a unique pauci-inflammatory infection of the cornea most commonly due to viridans type streptococci. We investigated the hypothesis that production of exopolysaccharide by streptococci, a property that can be induced by growth conditions, may contribute to the pathogenesis of infectious crystalline keratopathy by suppressing the ocular immune response. METHODS: Streptococcus sanguis type II was grown under two conditions, conventionally in brain-heart infusion broth and in 5% sucrose-supplemented brain-heart infusion broth, to promote exopolysaccharide formation. Rabbit corneas were inoculated by passage of 9-0 silk sutures soaked in bacterial suspensions. RESULTS: Arborizing, sharply demarcated pauci-inflammatory lesions were noted in 71% of rabbit corneas inoculated with S sanguis type II grown in sucrose-supplemented media and in 25% of control corneas (P = .05). Suppurative lesions developed in the remaining corneas. Histologic evaluation of infectious crystalline keratopathy lesions revealed characteristic features. CONCLUSION: Increased exopolysaccharide formation by S sanguis type II is associated with production of infectious corneal lesions that resemble those of infectious crystalline keratopathy.

Animals↗
PubMed1993

Invasive squamous cell carcinoma arising from asymptomatic choristomatous cysts of the orbit. Two cases and a review of the literature.

BACKGROUND: Epithelial choristomatous cysts are common orbital lesions, the most frequent of which are dermoid or epidermoid tumors. Massive enlargement or extraorbital extension of these benign lesions may occur. Malignant transformation of the epithelial lining of epidermoid cysts is rarely reported. METHODS: Two patients are presented in whom the epithelial lining of a previously asymptomatic choristomatous cyst of the orbit underwent malignant transformation to produce invasive squamous cell carcinoma. The unusual origin and clinical presentation of the lesions caused a delay in the diagnosis and therapy in both patients. Metastatic workup was negative in both patients, who underwent resection of their tumors via orbital exenteration with craniofacial resection. Reported cases of malignant transformation in analogous choristomatous cysts elsewhere in the cranium are reviewed. RESULTS: One patient is alive and well without recurrent disease 40 months postoperatively. The second patient died of a pulmonary embolus 2 months postoperatively. Autopsy showed no residual tumor. Overall, only 3 of 18 reported patients with epidermoid choristoma of the head and orbit with malignant transformation were alive when reported. CONCLUSIONS: Malignant squamous metaplasia is believed to be a rare complication of orbital dermoid or epidermoid cysts, with only two previously reported cases. However, malignant transformation is relatively frequent in analogous epidermoid cysts found elsewhere in the cranial vault, especially after incomplete excision. These reports encourage the complete removal of epithelial choristomas of the orbit.

Aged↗
PubMed1993

Pathology of cytomegalovirus retinitis treated with sustained release intravitreal ganciclovir.

BACKGROUND: An experimental sustained release intraocular device has been designed to deliver ganciclovir over a long period of time. As part of an efficacy trial, the ganciclovir intraocular device was used to treat cytomegalovirus (CMV) retinitis in patients with acquired immune deficiency syndrome (AIDS). METHODS: All patients had active CMV retinitis that had progressed despite intravenous ganciclovir therapy. The ganciclovir intraocular device was inserted into the vitreous cavity by making an inferotemporal full-thickness circumferential sclerotomy and anchored to the incision. Intravenous therapy was then discontinued and patients were followed up at 2-week intervals until death. Seven eyes from five patients were obtained 2 to 10 hours postmortem and submitted for histopathologic examination. Light and electron microscopic studies were performed and correlated to the clinical outcome. Follow-up period after device placement ranged from 16 to 82 days (median, 70 days). RESULTS: All seven eyes showed clinical stabilization of the CMV retinitis. Light microscopy showed varying degrees of retinal atrophy with areas of gliosis. In addition, we observed syncytial megalic cells containing Cowdrey type A inclusions affecting all layers of the retina. Concurrent choroidal infections with Pneumocystis carinii (1) and Mycobacterium avium (2) also were seen. Electron microscopy showed virus particles located mostly at the junction of uninvolved and "healed" retinitis. No evidence of retinal toxic effects or inflammation at the site of ganciclovir intraocular device implant was noted. CONCLUSION: The ganciclovir intraocular device appeared to be effective in controlling the progression of CMV retinitis. The clinical and pathologic results are similar to those observed in the eyes of patients with intravenously administered ganciclovir. The lack of toxic effects and sustained levels of intravitreal ganciclovir may provide an improved therapeutic method of local treatment of CMV retinitis.

AIDS-Related Opportunistic Infections↗
PubMed1993

Primary basal cell carcinoma of the limbal conjunctiva.

BACKGROUND: The authors describe a 66-year-old man with primary basal cell carcinoma of the conjunctiva. He presented with a fleshy nodular conjunctival lesion of 4 months' duration, located at the nasal limbus of the left eye. No associated cutaneous lesions were present. RESULTS: The lesion was completely excised, and results of histopathologic examination showed a primary basal cell carcinoma of the conjunctiva. CONCLUSION: This report provides clinicopathologic evidence that primary basal cell carcinoma can rarely occur in the conjunctiva. The authors summarize two well-documented previously reported cases of this unusual lesion.

Aged↗
PubMed1993

Immunoblastic B-cell malignant lymphoma involving the orbit and maxillary sinus in a patient with acquired immune deficiency syndrome.

BACKGROUND: A 44-year-old man was diagnosed with acquired immune deficiency syndrome (AIDS)-related complex in 1986. Four years later, erythema and swelling of the right lower eyelid and face and a palpable mass along the right inferior orbital rim developed. Computed tomographic scans of the orbits disclosed a mass involving the right superior antrum and inferior orbit. Histopathologic examination and immunohistochemical studies of the tumor were performed. METHODS: Immunohistochemical studies were performed on paraffin sections of the neoplasm. Markers used included leukocyte-common antigen and L26 (pan B-cell marker), and MT1, Leu22, polyclonal CD3, UCHL-1, and OPD4 (pan T-cell markers). Additional markers included cytokeratin, HMB-45, lysozyme, S-100 protein, kappa, and lambda. FINDINGS: The neoplastic cells were strongly to moderately positive with LCA, L26, MT1, and Leu22. Negative staining was observed with the remaining nine antibodies. CONCLUSION: Orbital lymphomas in patients with AIDS have been rarely documented; those few reported cases showed a B-cell phenotype. The authors report an immunoblastic B cell with immunophenotypic coexpression of T-cell markers.

Adult↗
PubMed1993

Glomus cell tumor of the eyelid.

BACKGROUND/METHODS: Glomus cell tumor, a vascular neoplasm, has been rarely reported to occur in the eyelid. The authors examined the clinicopathologic features of two patients with glomus cell tumor of the eyelid. RESULTS: The tumors occurred as enlarging violaceous to bluish masses. One patient had a solitary eyelid tumor that contained sheets of individual glomus cells. The other patient had eyelid and wrist tumors and multiple family members with similar lesions. CONCLUSION: This report provides clinicopathologic evidence that glomus cell tumor can occur in the eyelid in two different settings; in one setting, the tumor is solitary and sporadic, and in the second setting, it is multiple and familial.

Adolescent↗
PubMed1993

Intraepithelial corneal immunoglobulin crystals in IgG-kappa multiple myeloma.

A 52-year-old man was first examined because of bilateral superficial punctate keratitis. Slit-lamp examination disclosed numerous intraepithelial minute opacities in both corneas. A corneal biopsy revealed intraepithelial rhomboidal or rectangular crystals that immunohistochemically stained only for IgG-kappa. Serum immunoelectrophoresis demonstrated an IgG-kappa monoclonal gammopathy. Over the ensuing 6 years, the clinical appearance of the crystals changed from small dot-like opacities to polychromatic crystals. At this time, bone marrow examination established the diagnosis of multiple myeloma. Ophthalmologists should be aware of this entity and carefully monitor these patients; the corneal lesions may be the initial manifestation of an asymptomatic monoclonal gammopathy preceding the development of multiple myeloma.

Cornea↗