July 2002: 66-year-old female with a one-year history of progressive left proptosis.

The July 2002 Case of the Month (COM). This 66-year-old Caucasian female presented with gradually increasing protrusion of her left eye over a one-year period. She complained of increased tearing and foreign body sensation. The physical examination revealed a visual acuity of 20/20, normal color testing, full vision field with motility of her left eye limited in lateral gaze. Pupils were round, symmetric, with no afferent pupillary defect noted. On external examination, her left eye was grossly proptotic with resistance to retropulsion. She had 4 mm proptosis of the left eye. Computed tomography and MR imaging demonstrated a left retro-orbital mass with gadolinium enhancement and focal remodeling of orbital bones. She underwent surgical resection of tumor with a diagnosis of solitary fibrous tumor, and postoperatively she was symptom free. The histopathological differential diagnoses of spindle cell neoplasms of the orbit are discussed. Five months after surgery, no evidence of tumor recurrence was seen on neuroimaging and her vision was 20/20.

Solitary fibrous tumor of the orbit.

We report three cases of an orbital soft tissue lesion that fulfills the histologic, immunohistochemical, and electron microscopic criteria for solitary fibrous tumor, an entity previously described as a pleural tumor, but recently reported to occur in other locations. All three patients presented with proptosis. Two of the patients were cured by simple excision, and one patient had two recurrences, the last recurrence incompletely excised. The findings indicate that solitary fibrous tumor can occur in the orbit and, like solitary fibrous tumors of other anatomic sites, may behave in a nonaggressive or occasionally, locally aggressive fashion, with as yet no metastatic potential demonstrated in orbital lesions.

Vascular basophilia in ocular and orbital tumors.

The occurrence of vascular basophilia in ocular tumors has been a selective histologic feature of retinoblastomas. We recently observed a metastatic oat-cell carcinoma to the choroid which also demonstrated such a vascular hematoxyphilia. Histologic review of a variety of ocular and orbital metastatic carcinomas failed to yield a similar basophilic pattern. Examination of 100 consecutive retinoblastomas for vascular basophilia revealed an incidence of 6.0%. Similar material was not seen in any of 125 melanomas, including 10 with areas of necrosis. Histochemical studies showed the basophilic material to be DNA, and electron microscopy revealed the nuclear debris of pyknotic tumor cells to be continuous with identical material surrounding the adjacent blood vessels. The pathogenesis of vascular deposition of DNA in these two ocular tumors remains unclear. This finding most likely represents a form of tumor activity requiring comparatively healthy blood vessels to adequately precipitate liberated nucleic acids being filtered from the necrotic and degenerating tumor tissue.

Alveolar soft-part sarcoma of the orbit: a clinicopathologic analysis of seventeen cases and a review of the literature.

This is a clinicopathologic study of 17 cases of alveolar soft-part sarcoma of the orbit. The mean age of patients was 23 and the median was 18 (range, 11 months to 69 years); 13 patients (76.5 per cent) were women and four were men (ratio, 3.25:1). The right and left orbits were equally involved (eight patients each), and in one the laterality was not specified. Histologically, the tumors had a distinctive organoid pattern outlined by thin-walled capillaries and were composed of nests of large polyhedral cells with abundant, finely granular, acidophilic cytoplasm. Approximately two thirds of the tumors had diagnostic PAS-positive diastase-resistant crystalline structures. Histologically, the differential diagnosis included nonchromaffin paraganglioma, granular cell tumor, metastatic renal cell carcinoma, vascular tumor, alveolar rhabdomyosarcoma, and amelanotic malignant melanoma. Electron microscopic studies of one tumor disclosed mitochondria with abnormal cristae, increased amounts of glycogen, and cytoplasmic crystalline structures with a periodicity of 8 to 10 nm. Smaller membrane-bound electron-dense granules appeared to be precursors of the crystals. Follow-up studies showed that eight patients were alive and well (median follow-up period, 11.4 years). Six of the eight patients at the time of diagnosis were 20 years of age or younger. A ninth patient was alive and well 13 years after excision of the orbital mass and four years after bilateral thoracotomy with resection of nine pulmonary nodules. Two patients died as a result of metastatic disease, one 14 years and the other 21 years after initial orbital surgery. Two patients died of other causes, one of whom had pulmonary metastases at autopsy. The follow-up period on two recent cases was less than three years, and two patients were lost to follow-up. The disease pursued an indolent clinical course. Surgery offers the best chance to control the disease.

Melanotic schwannoma of the orbit. Immunohistochemical and ultrastructural study of a case and survey of the literature.

Light microscopical, immunohistochemical and ultrastructural study of a case of melanotic (pigmented) schwannoma in the left orbit of a 22-year-old man is presented. The tumour caused exophthalmus for three months and was located under the eyeball. Partial removal resulted in recurrence after three years. The recurrent tumour with extension to the nasal cavity and maxillary sinus was extirpated without loss of vision, and a year later the patient was without symptoms. The tumour tissue was Fontana positive, could be bleached, and showed immunoreactivity for S-100, vimentin and HMB 45. Ultrastructurally, the tumour cells, particularly the pigment loaded cells, showed a varying amount of basal lamina at the surface, melanosomes in varying stages of melanization, fine cytoplasmic filaments and micropinocytotic vesicles. Survey of the literature and discussion of the melanogenesis in Schwann's cells are presented.

Primary orbital neuroblastoma.

A 35-year-old man had a primary neuroblastoma of the left orbit. Histopathologically, the tumor was composed of uniform small round cells containing argyrophilic granules arranged in nests and cords with pseudorosettes, Homer-Wright rosettes, and a fine fibrillary background matrix. Immunohistochemical staining for chromogranin was positive. Electron microscopy showed small (108- to 173-nm) dense core granules. Eight years after surgery and radiation therapy the patient was free of local recurrence and metastases. To our knowledge, primary orbital neuroblastoma has been reported only once previously. Neuroblastoma, which occurs most frequently in children and has an incidence in the United States of 500 cases annually, is a distinctly unusual tumor in adults.

Ultrastructural comparison of capillary and cavernous hemangiomas of the orbit.

Capillary and cavernous hemangiomas are often grouped together as if they were modulations of the same entity. To clarify this nosologic question, three capillary hemangiomas in children and four cavernous hemangiomas in adults were studied by transmission electron microscopy. The capillary hemangiomas consisted of two variably admixed zones, solid cellular zones and zones with open vascular lumens. However, both zones had similar organization. Each vascular unit was composed of endothelial cells and pericytes, which persisted in a tumor three years after its clinical appearance. Macrophages and degenerating cells were found in the interstitium and may be related to the clinical feature of partial spontaneous regression. The cavernous hemangiomas had much larger lumens, and wider and more heavily collagenized trabeculae. The vascular walls were created by multilaminar smooth muscle cells. Therefore, capillary hemangioma is completely different from cavernous hemangioma, which resembles a venous tumor.

Primary carcinoid tumor of the orbit. A clinicopathologic study with histochemical and electron microscopic observations.

A patient with a primary carcinoid tumor of the orbit is described. No other tumor had been found during the 15-year interval since the onset of unilateral proptosis. Symptoms of the carcinoid syndrome were absent, and the urinary levels of 5-hydroxyindoleacetic acid were normal. Histologically, the bulky, noninfiltrating tumor compressed but did not invade the optic nerve. The argyrophilic cells were arranged in solid lobules and formed abundant, rosettelike structures. Pleomorphic neurosecretory granules were demonstrated by transmission electron microscopy.

Granular cell myoblastoma of the orbit. Report of a case.

A light and electron microscopical study of a case of granular cell myoblastoma of the orbit is described. Its possible histogenesis is discussed and, from the study of this case and of the literature, it is believed that the most likely histogenesis is from a primitive mesenchymal cell resembling a fibroblast.

Orbital metastasis from a carcinoid tumor. Computed tomography, magnetic resonance imaging, and electron microscopic findings.

An otherwise asymptomatic 63-year-old woman with a history of a carcinoid tumor of the ileum and a cutaneous melanoma of the shoulder developed unilateral proptosis. Orbital ultrasonography, computed tomography, and magnetic resonance imaging revealed a large, well-circumscribed orbital mass involving the superior rectus muscle. The surgically excised tumor was studied by light microscopy, histochemistry, and transmission electron microscopy. These studies confirmed the diagnosis of carcinoid tumor. The clinical and pathologic features of this rare type of orbital metastasis are discussed.

Postradiation leiomyosarcoma of the orbit complicating bilateral retinoblastoma.

A 31-year-old woman had bilateral retinoblastoma diagnosed in early childhood. The right eye was enucleated at the age of 1 year, and the left eye was treated with radiation therapy (a total dose of 16,000 rad). Twenty-three years later, in 1975, a subcutaneous mass was noted in the left periorbital region. A biopsy specimen of the mass was taken and a diagnosis of pleomorphic postradiation sarcoma was made. Electron microscopic studies of the periorbital mass confirmed the diagnosis of leiomyosarcoma. After additional radiation therapy, the residual mass was surgically excised. Five years later, a right renal mass, which histologically proved to be a renal cell carcinoma, was discovered. She was treated with nephrectomy, radiation, and chemotherapy. A recent follow-up examination disclosed that the patient is alive and apparently without any evidence of metastatic disease, 30 years after the diagnosis of bilateral retinoblastoma was made. The literature is reviewed regarding postradiation sarcomas and the occurrence of second malignant neoplasms in patients with retinoblastoma.

Juvenile fibrosarcoma of the orbit and eyelid. A study of five cases.

Five patients had juvenile fibrosarcoma of the orbit and eyelid. At initial surgical intervention, the patients ranged in age from newborn to 8 years (mean, 3 years 9 months). Three patients were male and two were female. Proptosis and/or painless swelling of the eyelid were the most common signs and symptoms. Four tumors grew within a few weeks or months, and all five were poorly circumscribed. They were composed of immature, spindle-shaped fibroblastic cells in a classic herringbone pattern or in interlacing fascicles. Hypercellularity and mitotic activity were present in all lesions. The differential diagnosis included rhabdomyosarcoma, fibromatosis, and fibrous histiocytoma. Electron microscopy confirmed the fibroblastic nature of the tumor cells in three cases. Follow-up ranged from one to 32 years (median, seven years). Two of five tumors recurred locally but none metastasized. Apparently surgical excision is the treatment of choice and the tumor has a favorable prognosis.

Multiple myeloma. Orbital involvement in a youth.

Orbital involvement by multiple myeloma is rare and affects older individuals usually. The youngest reported patient in a recent series that cites a median age of 56 years is 30 years of age. The present case involves a 19-year-old pregnant black female subject who complained initially of diplopia and whose presenting sign was proptosis. An extensive medical work-up and electron microscopic study were necessary to establish the diagnosis.

Large cell lymphoma of the orbit with microvillous projections ('porcupine lymphoma').

A 57-year-old man had a diffuse mass in the lacrimal gland area associated with extensive bony destruction. A malignant epithelial tumor of the lacrimal gland was suspected clinically, and a biopsy specimen disclosed an undifferentiated malignant neoplasm of uncertain origin. Ultrastructural studies, however, revealed features of a lymphoid tumor with myriad cytoplasmic microvillous projections. The patient has had no evidence of systemic lymphoma after more than three years of follow-up. To our knowledge, this is the first report of orbital involvement of a large cell lymphoma with microvillous projections ("porcupine lymphoma"). The role of electron microscopy in the differential diagnosis of this orbital tumor was important, since epithelial tumors of the lacrimal gland are best managed by surgical excision, whereas lymphoid tumors usually respond satisfactorily to radiotherapy.

Poorly differentiated primary orbital sarcoma (presumed malignant rhabdoid tumor). Radiologic and histopathologic correlation.

A 47-year-old man presented with acquired hyperopia and gaze-evoked visual loss. Computed tomography and magnetic resonance imaging demonstrated a well-circumscribed intraconal tumor. Histopathologic studies indicated that the tumor was a poorly differentiated primary orbital sarcoma compatible with malignant fibrous histiocytoma or malignant rhabdoid tumor. To our knowledge, no case of primary orbital malignant rhabdoid tumor has been previously described in an adult.

Orbital and adnexal lymphomas. A multiparameter approach.

The application of immunologic, cytochemical, and electron-microscopic technics to the study of lymphoid lesions of the orbit and adnexa was found to enhance the accuracy of diagnoses of malignant lymphoma in five challenging referral cases. Although careful specimen collection, ideal fixation, and processing constitute the cornerstone of the morphologic diagnosis of nodal and extranodal lymphomas, the immunologic characterization of these lymphoproliferative disorders is emphasized as an especially useful diagnostic parameter. The occurrence of false-negative diagnoses of pseudolymphoma of the orbital region may be partially explained by a failure to recognize the relatively frequent plasma-cytoid lymphocytic lymphoma, a distinctive entity that may mimic a reactive inflammatory process. All of the cases of malignant lymphoma reported represented stage I or stage II disease, suggesting that primary lymphoma of the orbital region may be a disease with a favorable prognosis.

Granular cell tumor of the orbit and ocular adnexae.

Although granular cell tumor (GCT) has been a distinct pathological entity since 1926, confusion and controversy have long existed regarding the nature and histogenesis of the tumor. Twenty-five cases of granular cell tumor involving the orbit and ocular adnexae previously reported in the ophthalmic literature, are reviewed and six additional cases are reported. The histopathological and immunohistochemical characteristics of granular cell tumors in this uncommon location are discussed and their probable origin from Schwann cells is also considered.

Multiple periorbital fibrous histiocytomas: a light and electron microscopic study.

Recurrent, bilateral, multiple, periorbital fibrous histiocytomas occurred in a 62-year-old woman. There were no associated serum lipid abnormalities. Histologically, the tumor was composed of an admixture of lipid-laden histiocytes and fibroblasts with a variable amount of collagen production. In many areas the fibroblasts were arranged in a storiform pattern. No cytologic evidence of malignancy was observed. Ultrastructural studies of the tumor showed histiocytic cells with a variable amount of lipid in the cytoplasm and fibroblasts with mild to moderate collagen production. Differential diagnosis and histogenesis are discussed.

Leiomyoma of the orbit.

A 5-year-old boy had a one-year history of inability to adduct the left eye and redness. Examination showed a medial orbital mass indenting the globe without proptosis. A well-encapsulated mass was removed surgically. On light microscopy it seemed to be a neurofibroma. Transmission electron microscopy showed that the tumor was composed of cells with cigar-shaped nuclei, cytoplasmic and plasmalemmal densities, fine filaments, surface-connected vesicles, and basement membrane. These features were characteristic of leiomyoma.

Orbital intramuscular schwannoma.

In an 8-year-old girl with asymptomatic proptosis, computed tomographic scans showed a large medial orbital mass that contoured the globe anteriorly, bowed the optic nerve laterally, and extended posteriorly to the orbital apex. T1-weighted coronal magnetic resonance images showed the mass to be a diffusely enlarged medial rectus muscle. Histopathologic examination of a medial rectus muscle biopsy specimen disclosed a multinodular, intramuscular schwannoma, separating and infiltrating normal skeletal muscle fibers. The intramuscular location and multinodular configuration of this tumor, together with its occurrence in a child, distinguish it from previous orbital schwannomas.