Soft sheets of fibrillar bone from a fossil of the supraorbital horn of the dinosaur Triceratops horridus

Soft fibrillar bone tissues were obtained from a supraorbital horn of Triceratops horridus collected at the Hell Creek Formation in Montana, USA. Soft material was present in pre and post-decalcified bone. Horn material yielded numerous small sheets of lamellar bone matrix. This matrix possessed visible microstructures consistent with lamellar bone osteocytes. Some sheets of soft tissue had multiple layers of intact tissues with osteocyte-like structures featuring filipodial-like interconnections and secondary branching. Both oblate and stellate types of osteocyte-like cells were present in sheets of soft tissues and exhibited organelle-like microstructures. SEM analysis yielded osteocyte-like cells featuring filipodial extensions of 18-20μm in length. Filipodial extensions were delicate and showed no evidence of any permineralization or crystallization artifact and therefore were interpreted to be soft. This is the first report of sheets of soft tissues from Triceratops horn bearing layers of osteocytes, and extends the range and type of dinosaur specimens known to contain non-fossilized material in bone matrix.

Reconstruction of orbital defect in rabbits with composite of calcium phosphate cement and recombinant human bone morphogenetic protein-2

BACKGROUND

Calcium phosphate cement (CPC) is a biocompatible and osteoconductive bone substitute, and recombinant human bone morphogenetic protein-2 (rhBMP-2) has strong osteoinductibility, therefore we developed a composite bone substitute with CPC and rhBMP-2 and evaluate its reconstruction effect in rabbit orbital defect.

METHODS

Thirty-six rabbits were randomly divided into two groups and a 5 mm × 5 mm × 2 mm bone defect in the infraorbital rim was induced by surgery in each orbit (72 orbits in all). The orbital defects were treated with pure CPC or composite of CPC and rhBMP-2. The osteogenesis ability of different bone substitute was evaluated by gross observation, histological examination, histomorphometrical evaluation, compressive load-to-failure testing, and scanning electron microscope (SEM).

RESULTS

Gross observation showed that both bone substitutes were safe and effective for reconstruction of orbital defect. However, histological examination, histomorphometrical evaluation and SEM showed that CPC/rhBMP-2 group had faster speed in new bone formation and degradation of substitute material than CPC group. Compressive load-to-failure testing showed that CPC/rhBMP-2 group had stronger compressive strength than CPC group at every stage with significant difference (P < 0.05).

CONCLUSION

Composite of CPC/rhBMP-2 is an ideal bioactive material for repairing orbital defect, with good osteoconductibility and osteoinductibility.

Structural details of rat extraocular muscles and three-dimensional reconstruction of the rat inferior rectus muscle and muscle-pulley interface

Light microscopy, electron microscopy and morphometry revealed structural details and allowed generation of a three-dimensional reconstruction of the pulley and muscle-pulley interface of extraocular muscle. The inferior rectus orbital layer was bifurcate in shape and extended anterior to the pulley. The putative pulley structure itself was asymmetric; loosely attached at the orbital aspect it adhered tightly to the global aspect of muscle. Orbital multiply innervated fiber proportion increased anterior to the pulley insertion site. Additionally longitudinal variation in juxtaposition of orbital and global layers was noted. These newly described structural details provide novel mechanistic insight for extraocular muscle function in rats.

Anatomy, histology, histochemistry and fine structure of the Harderian gland in the South American armadillo Chaetophractus villosus (Xenarthra, Mammalia)

The anatomical, histological, histochemical and ultrastructural characteristics of the Harderian gland of the armadillo Chaetophractus villosus were described. The gland is the largest structure in the bony orbit. It is situated in the anteroventral region of the orbit. Obvious structural differences are not observed between males and females. The gland is compound-branched tubulo-alveolar, being characterized by a single layer of columnar cells surrounded by myoepithelial cells. It possesses a single excretory duct opened into the inner canthus. All glandular cells show yellow-green autofluorescence and additionally some glandular lumen may contain dense autofluorescent solid accretions. There are two peculiar and outstanding cytoplasmic features. One is represented by the smooth endoplasmic reticulum (SER), forming a closely woven meshwork. The other one is represented by "membranous bodies" apparently derived from the SER, RER and cytoskeleton with a "Star of David" configuration situated in the supranuclear region. Three types of vesicles are detected in the cytoplasm. Histochemical staining methods reveal lipids, proteins, neutral and acidic containing glycoconjugates in secretory vesicles. The mechanism of secretion appears either merocrine or apocrine. The epithelium of the intra- and inter-lobular excretory ducts suggests secretory activity. Tubulo-acinar glands similar to those seen in the lacrimal gland and nictitans glands are found related to the intralobular and main excretory ducts. The capillary network is characterized by fenestrated endothelium. The stroma possesses unmyelinated axons and plasma cells. The normal secretion of the secretory endpieces, particularly lipids, proteins and glycoconjugates, is complemented by mucous and serous secretions released by ductal cells and glands associated to the ducts.

[Ultrastructure analysis and cytokines expression of orbital fibroblasts in the patients with thyroid-associated ophthalmopathy]

OBJECTIVE

To analyse the ultrastructure and cytokines expression from cultured orbital fibroblasts (OFs) in the patients with thyroid-associated ophthalmopathy (TAO).

METHODS

Primary cultured OFs were obtained from 5 patients with TAO and 4 normal control subjects, some of subcultured OFs were treated by patients' serum with active TAO. Ultrastructures of OFs were observed by transmission election microscope. The cytokines in cultured supernatant were detected by enzyme linked immunosorbant assay (ELISA).

RESULTS

There were no significant differences of ultrastructure of OFs from TAO patients and normal subjects. Nucleoli enlargement, microvillus prolongation and increase of endoplasmic reticular of OFs were detected after maintaining in culture. The IL-1, TNF-alpha and IFN-gamma were found in supernatant of OFs treated by patients' serum. IL-1 was found in supernatant of OFs in TAO patient and control subjects, and the IL-1 level of former was higher than the controls.

CONCLUSION

There are no significant differences in ultrastructure of OFs from patients with TAO and normal subjects. The OFs treated with the serum of TAO patients showed proliferation and increasing cytokines secretion.

Morphological studies of the optic canal

BACKGROUND

In some cases of closed head injuries after minor blunt trauma, an amaurosis can occur. Our knowledge concerning the pathophysiological mechanisms of traumatic optic neuropathy is limited. The aim of this study is to analyze the morphology of the optic canal in order to understand the effect of mechanical forces in the optic canal and the consecutive injuries.

METHODS

Forty-one optic canals from body donors were analyzed by light microscopic, polarization microscopic, immunohistochemical and scanning electron microscopic techniques.

RESULTS

In the optic canal, collagen fibrils of the dural sheath are organized in a scissor-like pattern. Within this collagen network multiple vessels are integrated. The main component of the extracellular matrix is collagen type I. The dural sheath and pial sheath are connected by collagen bundles. Parallel to these bundles, small vessels form anastomoses between the dural and pial vessel systems. In the arachnoidea, no blood vessels can be detected by immunohistochemical techniques.

CONCLUSIONS

Based on morphological findings, the following pathophysiological mechanisms can be discussed in cases of blunt closed head injury with consecutive amaurosis: 1. Squeezing and rupture of nutritive vessels by transduction of shearing forces via the scissor-like collagen network. 2. Atrophy by pressure of the optic nerve after injury to the microvasculature followed by formation of microhematomas and reactive edema. 3. Direct injury of axons of the optic nerve by shearing forces within the optic canal. These mechanisms should be studied further in the future.

The cavernous body of the human efferent tear ducts: function in tear outflow mechanism

PURPOSE

To determine the structure and function of a system of large blood vessels integrated in the bony canal between the orbit and the inferior nasal duct.

METHODS

Thirty-one dissected lacrimal systems of adults were analyzed by using gross anatomy, histology, and electron microscopy as well as corrosion vascular casts.

RESULTS

More than two thirds of the bony canal between orbit and inferior nasal duct is filled by a plexus of wide-lumened veins and arteries. The vascular system is embedded in the wall of the lacrimal sac and nasolacrimal duct and is connected to the cavernous tissue of the inferior turbinate. Three types of blood vessels can be distinguished inside the vascular tissue that surrounds the lumen of the lacrimal passage: barrier arteries, capacitance veins, and throttle veins.

CONCLUSIONS

The surrounding vascular plexus of the lacrimal sac and nasolacrimal duct is comparable to a cavernous body. While regulating the blood flow, the specialized blood vessels permit opening and closing of the lumen of the lacrimal passage, effected by the bulging and subsiding of the cavernous body, and at the same time regulate tear outflow. Other functions such as drainage of absorbed tear fluid components and a role in immunologic response are under discussion as well. Malfunctions in the cavernous body may lead to disturbances in the tear outflow cycle, ocular congestion, or total occlusion of the lacrimal passages. Variations in the conditions for swelling of the cavernous tissue may have led to the (mistaken) description of valves in the lacrimal passage.

Scanning electron microscopy study of the tarsal and orbital conjunctival surfaces compared to peripheral corneal epithelium in pigmented rabbits

The mammalian palpebral conjunctiva has not been systematically evaluated by scanning electron microscopy (SEM). The upper eyelid of female grey rabbits (2 kg) was fixed in its extended conformation at 15.00 h; some corneas were prepared with the same fixative protocol. The corneal epithelium, within 1 mm of the limbus, is a mosaic of small-to-large (average cell area of 693 m2) squamous cells with light, medium or dark appearance due to different densities of cell surface microplicae. The tarsal conjunctiva was a 1.5 to 3 mm wide mosaic of small (average cell area of 86 microm2) non-desquamating polygonal cells having distinctive light and dark appearances due surface microplicae. The orbital portion of the palpebral conjunctiva is also composed of small (average cell area of 87 microm2) non-desquamating polygonal cells but with a uniform medium-grey appearance due to a relatively consistent density of surface microvilli. Several types of intercellular pore-like openings were also present across the palpebral surface but not the corneal epithelial surface. Very small type 1 pores (1.5 to 5 microm diameter) were present at a density of 480 to 760 / mm2 for the tarsal and 80-160 / mm2 for orbital conjunctiva. Slightly larger (2.5 to 18 microm diameter) type 2 pores with distinct borders were present at 120-200 / mm2 across the orbital conjunctiva. Very large (10-109 microm diameter) type 3 (Henle) pores were present at 40 to 280/mm2 especially at the tarsal/orbital transition zone. Type 4 pores (goblet cell orifices) were oval with a peripheral ring of microvilli and were present at 40 to 160/mm2 for tarsal and 800 to 1600/mm2 for orbital conjunctiva. The rabbit palpebral conjunctival surface is thus distinctly different from the peripheral corneal epithelium across which it slides following eyelid closure.

Hydroxyapatite orbital implant. A light- and electron-microscopic and immunohistochemical study

OBJECTIVE

This study aimed to characterize the constituents of the ingrown host tissue in explanted orbital coral spheres by means of light electron microscopy and immunohistochemistry and to compare findings at different intervals after implantation.

DESIGN AND METHODS

A microscopic retrospective laboratory study of three explanted coral spheres from three different patients was undertaken. The first specimen was an infected hydroxyapatite orbital implant, which was removed after 18.5 months and processed for standard light microscopy and transmission electron microscopy. Immunohistochemistry was performed using vimentin, actin, CD-68, and CD-34 marker. Two other explanted spheres (after 3 weeks and 2.5 months) were examined by light microscopy only, because no fibrovascular ingrowth could be detected.

RESULTS

On light microscopy, the pores of the first coral were filled entirely with the fibrovascular tissue. A basophilic line reminiscent of calcium deposition was seen along hydroxyapatite spicules, where it often was associated with newly formed bony lamellae. Similar lines were seen partially in the 2.5-month specimen but not in the 3-week specimen. Immunohistochemistry of the first specimen enhanced visualization of the capillary network when the CD-34 marker was used. The fibrovascular tissue was uniformly vimentin-positive and partially actin-positive. On transmission electron microscopy, typical fibroblasts and myofibroblasts were observed. The latter were separated by thin sheets of banded collagen and formed pseudoepithelial structures. Proliferating vessels often showed high endothelial cells.

CONCLUSIONS

The fibrovascular ingrowth contains not only vimentin-positive regular fibroblasts but also actin-positive myofibroblasts. Interaction between the invading tissue and hydroxyapatite structures leads to long-term ossification.

Malignant fibrous histiocytoma of the lateral wall of the orbit

A 58-year-old male presented with malignant fibrous histiocytoma originating from the lateral wall of the orbit, manifesting as left exophthalmos and diplopia on left lateral gaze. Magnetic resonance (MR) imaging demonstrated the tumor extending into the left orbit and under the temporalis muscle. The tumor was isointense with muscle on T1-weighted MR images and was surrounded by a low-intensity rim, which was proved to be the capsule after histological examination. The tumor was completely removed after detaching the lateral orbital rim and zygomatic arch using the dismasking flap method. He underwent one course of CYVADIC chemotherapy and has demonstrated no recurrence for 1 year and 6 months postoperatively.

Total integration of an ocular implant/prosthesis: preliminary in vivo study of a new design

An ocular implant designed to simplify surgical implantation, minimize infection and extrusion, and improve motility when used as a prosthetic replacement for eyes removed because of damage or disease was tested in rabbit eyes. The implant consisted of a silicone sphere with patches of porous silicone elastomer at the natural insertion sites of the extraocular muscles. Nine implants also had patch material around the base of an integral post designed to distribute the weight of and transfer motility to an overlying prosthetic conformer. Six implants without posts had a circular porous patch on the central anterior surface to facilitate closure of the conjunctiva and Tenon's capsule. Biocompatibility and feasibility were tested in rabbit eyes for < or = 1 year. The patches promoted conjunctival ingrowth, leading to positional stability, and facilitated adherence of the extraocular muscles. Patch material around the post or on the anterior conjunctival surface enhanced conjunctival closure and healing. All 15 implants were retained with no signs of migration, conjunctival dehiscence, or extrusion. Motility on forced duction testing was significant in all directions. The materials appeared to be biocompatible, and the design with the post provided good motility, with the potential for improved coordinated eye movement as a result of the specifically localized attachment of the extraocular muscles.

Electron microscope investigation of polytene chromosomes in the Mediterranean fruit fly Ceratitis capitata

Ultrastructural analyses of polytene chromosomes from male pupal orbital bristle cells and from larval salivary glands of Ceratitis capitata were carried out. It was shown that chromatin complexes corresponding to the X chromosome heterochromatic network are surrounded by material containing ribonucleoprotein (RNP) granules 250-300 A (1 A = 0.1 nm) in diameter. RNP granules of similar size surround the spherical Y chromosome. These data point out the presence of transcriptional activity in both of these chromosomes. The absence of clear structure in chromosomal regions situated between large bands in both types of tissues was observed. These results support the hypothesis of weak synapsis between chromatids or small chromomeres of polytene chromosomes in this species. In addition, we describe a specific puff revealed in both orbital trichogen cells and salivary glands that is morphologically similar to the 93D puff of Drosophila melanogaster.

Spontaneous intraorbital hematoma mimicking orbital neoplasm--case report

A 66-year-old female presented with spontaneous intraorbital hematoma manifesting as left exophthalmos after left eye discomfort persisting for 5 months. She had no history of head injury. Computed tomography revealed a round mass in her left orbit which was slightly high density with no postcontrast enhancement. A blood cyst was extirpated through frontotemporal craniotomy. Histological findings showed no tumor or vascular anomaly. Spontaneous intraorbital hematoma with insidious symptoms is extremely rare and should be considered in the differential diagnosis of orbital mass lesions.

Ultrastructure of cultured human orbital fibroblasts

The fine structure of cultured human orbital fibroblasts was investigated by transmission electron microscopy. One culture was derived from a patient with severe Graves' ophthalmopathy, the other from a donor without inflammatory orbital disease. Despite their known differences in metabolism, orbital fibroblasts from either source revealed no ultrastructural differences. The cells had extensive thin cytoplasmic processes. The perinuclear areas contained multiple assemblies of Golgi membranes, modest amounts of rough endoplasmic reticulum, intermediate filaments, and lysosome-like structures. Glycogen deposits were noted both in the perinuclear cytoplasm and in the thin processes. These ultrastructural features of orbital fibroblasts are the same as those of fibroblasts from other anatomic regions.

Connective tissue of the orbital cavity in retinal detachment: an ultrastructural study

The connective tissue from Tenon's capsule of 7 patients who underwent surgery for retinal detachment was studied ultrastructurally. Five patients were 58-70 years old, and 2 were young adults. The Tenon capsules of 6 children and of 2 aged patients without retinal problems were used as controls. In young controls the Tenon capsule was composed mainly of round, smooth collagen fibrils and a few elastic fibers. The collagen fibrils varied in size from 70 to 110 nm. In the aged patients with retinal detachment, the collagen fibrils showed marked variation of size and also abnormalities of shape in 4 out of 5 cases. The diameter of collagen fibrils varied from 32 to 160 nm, and the elastic fibers were fewer as compared with controls. The possibility arises that age-related structural changes of the orbital connective tissue could predispose to retinal detachment.

Immunohistological and electron microscopical study of nodular fasciitis of the orbit

We report the case of a 7-year-old Japanese girl with nodular fasciitis which was investigated by immunohistological and electron microscopical methods. An excised nodular lesion in her right orbit showed characteristic histological features of the disease. The fibroblastic cells showed myofibroblastic characteristics, such as immunohistochemically positive reactions against muscle specific actin and vimentin and characteristic electron microscopical appearances. The multinuclear giant cells did not react against any histiocytic markers, including HLA-DR, antimacrophage antigen, lysozyme, and S-100 protein, but the myofibroblastic markers and the electron microscopical study did reveal myofibroblastic characters.

[Clinical analysis of orbital cavernous hemangiomas]

CT and B-ultrasonography in combination with clinical manifestations facilitated the diagnosis and orientation of 40 cases of orbital cavernous hemangioma. The surgical approach depended on the size and location of the tumors as determined by axial and coronal CT, and mostly adopted was the route of lateral orbitotomy. The prevention of complications was discussed.

Electron-microscopic identification of pseudoexfoliation material in extrabulbar tissue

The structure and distribution of pseudoexfoliation material in extrabulbar tissues from five eyes with typical unilateral intraocular pseudoexfoliation syndrome and two intraocularly unaffected fellow eyes were examined by transmission electron microscopy. In all seven eyes, unevenly distributed pseudoexfoliation aggregates were found in limbal conjunctivae, extraocular rectus and oblique muscles, orbital connective-tissue septa, and the walls of the posterior ciliary arteries, vortex veins, and central retinal vessels passing through the optic nerve sheaths. Typical pseudoexfoliation fibers occurred in close association with connective-tissue components, especially elastic fibers; a moderate predisposition of pseudoexfoliation clumps to accumulate around blood vessels was observed. The findings of pseudoexfoliation material in similar extrabulbar locations in intraocularly uninvolved fellow eyes indicates that pseudoexfoliation fiber formation outside the globe precedes its intraocular manifestation. The intermingling of pseudoexfoliation fibers, microfibrils, and elastic and collagen fibers suggests that pseudoexfoliation fiber formation might result from a disordered synthesis and/or assembly of connective-tissue microfibrils.

Extra-skeletal Ewing's sarcoma of the nasal fossa

Extraskeletal Ewing's sarcoma is rarely found arising in the head and neck region. An unusual case arising in the nasal fossa in a young child is reported and the differential diagnosis, pathology and treatment discussed.

Ultrastructure of the orbital pathway for cerebrospinal fluid drainage in rabbits

An increasing number of physiological and morphological studies indicate that cerebrospinal fluid (CSF) drains via nonarachnoidal pathways in several mammalian species. Ultrastructural tracer studies were undertaken to examine the orbital route for CSF absorption in the rabbit. At the termination of the optic nerve subarachnoid space, an area of connective tissue containing numerous small tortuous channels is present. Ferritin (molecular weight 400,000) infused into the ventricles at normal and increased intraventricular pressure was present in these channels by 15 minutes postinfusion, and subsequently reached the intraorbital connective tissue. Elevating the intraventricular pressure did not noticeably alter the morphological appearance of this region or change the gross distribution pattern of the ferritin. Ferritin did not penetrate the scleral barrier to reach the choriocapillaris, nor did it breach the arachnoid barrier layer proximal to the transitional zone at the optic subarachnoid space to reach the dura mater. These results are very similar to those described for the hamster orbital region and the rabbit cribriform region. These experiments support the concept that macromolecules exit the subarachnoid space at the termination of the optic nerve via open channels, and that no significant barrier to drainage of macromolecules in CSF is present at this location.

Scanning electron microscopy of human ocular vascular casts: the submacular choriocapillaris

Vascular casts were prepared from ten human orbits removed at autopsy from patients with no previous history of vascular disease. The ages ranged from 7 months to 68 years. The time interval between death and injection of the orbit was always less than 12 h. The vascular casts were examined under scanning electron microscopy with particular attention to the submacular region. We present photomicrographs of common findings seen in each of our specimens, and discuss our results with respect to current models of the submacular angioarchitecture.

Orbital involvement with desmoplastic melanoma

A 79-year-old woman developed an orbital mass five and a half years after excision of a cutaneous melanoma from the side of the nose. The initial orbital biopsy was interpreted histopathologically as a malignant fibrous histiocytoma, but special stains and electron microscopy showed it to be a desmoplastic malignant melanoma which had apparently spread to the orbit from the prior skin lesion by neurotropic mechanisms. The occurrence of a desmoplastic neurotropic melanoma in the orbit has not been previously recognised. The problems in the clinical and pathological diagnosis of this rare type of melanoma are discussed.

The anatomy and histology of the anophthalmic socket--is the myofibroblast present?

For some anophthalmic patients, the contracted socket is a severe problem that precludes the wearing of a prosthesis. A normal and cosmetically acceptable appearance is dependent on the ability of a socket to retain a prosthesis. The disfigurement and distress caused by the contracted socket and its inability to accommodate a prosthesis may have a profound detrimental effect on the patient's career, self-esteem, and psychosocial interactions. The tissue dynamics at work in the anophthalmic socket and in the contracting socket are not yet understood. There are many unanswered questions regarding the histology and anatomy of the normal, as well as the contracting, socket. The tissue responsible for clinical contraction has not been identified. This thesis, using the cynomolgus monkey socket as an experimental model, investigated healing in both the normal and contracting socket. Qualitative observations of the anatomy and histology of eight sockets were made. Two of the sockets were treated with Croton oil to induce contractions. Biopsy specimens from two human sockets, one contracted and the other merely volume deficient, were also examined. Histopathology of the normal and contracting sockets were compared. Myosin subfragment 1 staining of actin for electron microscopy and immunoperoxidase staining of actin for light microscopy were performed on selected specimens. The myofibroblast, probably a modified fibroblast, is known to be present in the early stages of open wound healing and in contracting scar tissue elsewhere in the body. The myofibroblast has been incriminated as an agent generating contractile force. Under the conditions of this experiment, cells with the characteristics of myofibroblasts were identified by both immunoperoxidase staining and electron microscopy. They were found in healing noncontracting and contracting sockets. Cytoplasmic actin was also distinguished in arterioles, venules, capillaries, myoepithelial cells, smooth muscle, and skeletal muscle.

Immunohistochemical and ultrastructural studies on the exenterated orbital tissues of a patient with Graves' disease

The exenterated orbital contents obtained post mortem from a 47-year-old man who had an eight-month history of treated hyperthyroidism and a two-month history of visual complaints were examined histopathologically, immunohistochemically, and by electron microscopy. All of the extraocular muscles were massively enlarged, due to early diffuse endomysial fibrosis, mucopolysaccharide deposition, and a predominantly perivascular lymphocytic and plasmacytic infiltration. Histochemical stains revealed that the intramuscular mucopolysaccharides were weakly sulfated and polycarboxylated, establishing that they were products of fibroblastic activation rather than derived from mast cells. Subsarcolemmal deposits in the myofibers were shown by electron microscopy to be collections of glycogen rosettes with intermixed lipid deposits. These inclusions were interpreted as secondary phenomena due to abnormal muscle energetics from restrictions in contractility, and not as evidence of a primary degeneration of the extraocular muscle fibers themselves. The sarcomeric organization of the striated muscle cells was undisturbed, and therefore the pathologic changes occurred int he interstitial space of the endomysium. A monoclonal antibody specific for neurofilaments (antibody 4.3 F9) revealed, in comparison with normal controls, a preferential loss of large-type axons of the proximal segment of the orbital portion of the optic nerve as well as in the intracanalicular portion. The axonal loss was associated with a mildly increased number of astrocytes as demonstrated by an antibody against glial fibrillary acidic protein. The meninges of the optic nerve, the orbital fat, and the tendons of the extraocular muscles were uninflamed. The foregoing findings are compatible with a compressive optic neuropathy mediated by the massively swollen extraocular muscles impinging upon the optic nerve at the orbital apex.

Epithelioid angiosarcoma of the orbit presenting as Tolosa-Hunt syndrome. A clinicopathologic case report with review of the literature

The clinical diagnosis of Tolosa-Hunt syndrome was first considered in a 66-year-old man with facial pain and diplopia. A complete neuroradiologic evaluation as well as an oncologic work-up yielded normal results. Several courses of oral prednisone provided no significant benefit. Within a year the patient became clinically worse and a CT scan disclosed an abnormal area of enhancement at the left orbital apex. An orbital exploration was performed elsewhere and a histologic diagnosis of myositis was obtained. Because of further worsening the patient was re-evaluated 3 months later and a CT scan showed a mass in the left orbital apex and superior orbital fissure. A second orbital exploration was performed and a sausage-shaped mass encompassing the optic nerve was excised. By light microscopy a poorly differentiated malignant tumor was infiltrating the orbital tissues with areas of intra- and perineural invasion. The tumor cells were arranged in strands and tubules with a definite tendency to form lumens that often contained red blood cells. Electron microscopic studies disclosed features consistent with a neoplasm of endothelial cell origin displaying a polarized basal lamina and rare micropinocytotic vesicles on the luminal side. The presence of multiple, slender microvilli and sometimes tonofilaments as well as desmosomes were interpreted as epithelioid metaplasia of an angiosarcoma.

Eosinophilic granuloma of the soft tissue in the orbit

A 61-year-old Japanese man was treated for eosinophilic granuloma of the soft tissue in the orbit. The clinical characteristics were typical for eosinophilic granuloma of the soft tissue: 8% eosinophils, very soft tumor masses in both orbits, multifocal lesions including the salivary glands, good response to steroid hormone, and hypergammaglobulinemia. The ocular signs were exophthalmos and lid swelling. Light microscopy showed many lymphoid follicles with many eosinophils, also in other parts of the body. The previously reported cases of orbital lesion are reviewed. Patients with orbital eosinophilic granuloma of the soft tissue are apt to be 30-50 years of age, older than patients without ocular lesions.

A case of mesenchymal chondrosarcoma of the orbit

A case of mesenchymal chondrosarcoma occurring in the right orbit of a 84-year-old Japanese female was reported. The ultrastructural findings of tumour are composed of three cell types: well-differentiated cartilaginous cells, undifferentiated cells and transitional cells. The well-differentiated cells showed scalloped cytoplasmic membranes, numerous mitochondria showing dense electron matrix, various size of lipid granules, and abundant amount of extracellular matrix. The extracellular matrix were collagen fibres and ground substances and matrix vesicle. The undifferentiated cells showed smooth cytoplasmic membranes, large nuclei resembling primitive mesenchymal cells.

Experimental evaluation of ceramic calcium phosphate as a substitute for bone grafts

Tricalcium phosphate (Synthos) is a bioceramic material which can be carved with a scalpel and wired into place as a bone graft would be. The process of bone replacement of the prosthesis begins with an ingrowth of cellular loose connective tissue, which is replaced later by dense connective tissue. Around the periphery of this dense fibrous connective tissue, osteoid tissue becomes evident and on later specimens this mixture seems to be converted to bone--which at first is in the form of spicules but later takes on the characteristics of lamellar bone (with tricalcium phosphate particles seen within its lacunae). The progressive replacement occurs in a circumferential pattern, but most heavily at the bone-prosthesis interface. Although the periosteum is beneficial, we do not feel that the major source of bone formation is as the soft tissue or subperiosteal area. The replacement of the tricalcium phosphate prosthesis is slower than we originally thought, or than reported by others. We have noted pockets of tricalcium phosphate, incompletely replaced, in dogs up to 18 months after implantation. We believe this may be related to the larger sized prostheses we used (2 x 2 cm blocks) with, therefore, longer distances that the ingrowth and calcification had to traverse.

Electron microscopic study of the orbital lesion of Hand-Schüller-Christian disease

The orbital bone lesion of a patient with Hand-Schüller-Christian disease was examined by electron microscopy. Vacuoles in the cytoplasm of foam cells contained granules which were shown by histochemical examination to be cholesterin. Langerhans cell granules in the histiocytes of Hand-Schüller-Christian disease showed a close resemblance to those in Langerhans cell of the epidermis, eosinophilic granuloma and Letterer-Siwe disease. Charcot-Leyden crystals appeared to be formed in the lysosomes of histiocytes in Hand-Schüller-Christian disease. From histopathological and cytological points of view, eosinophilic granuloma, Hand-Schüller-Christian disease and Letterer-Siwe disease are classified as histiocytosis X. The simultaneous appearance of Langerhans cell granules and Charcot-Leyden crystals is specific in histiocytosis X.

Metastatic tumor of the orbit

Metastatic tumor occurred in the right orbit of a 50-year-old woman 5 years following bilateral mastectomy. The tumor caused enophthalmus, ptosis and restriction of the ocular movements. The tumor consisted of nondifferentiated cells. Transmission and scanning electron microscopic appearance of the tumor is also reported.

Granular cell tumor (myoblastoma) of the orbit

An 8-year-old white boy had a tumor in the left orbit with clinical manifestations of muscular impairment, exophthalmos, and reduced visual acuity. Five months after exenteration of the orbit the boy was healthy without tumor recurrence. Based on our observations with electron, light, and phase microscopy, and histochemical studies, we conclude that this tumor is benign, of histiocytic origin, and we propose the term granular cell histiocytoma be used to describe this entity.