Immunofluorescence localization of cystatins in human lacrimal gland and in the exorbital lacrimal gland of the rat.

Cystatins are widely distributed natural inhibitors of cysteine proteinase. They occur both intra and extracellularly in various cells and tissue fluids including tears. Using an immunofluorescence technique with antibodies against rat cystatin S, an inhibitor of submandibular gland origin, cystatin-like immunoreactive material was demonstrated in the acinar cells of the exorbital lacrimal gland of the rat. Administration of the cholinergic agonist carbachol caused a depletion of cystatin from the acinar cells. This depletion was followed by a partial restitution in 6-8 h. Administration of the beta-adrenergic agonist isoproterenol for 4 days, which caused a marked hypertrophy of the submandibular gland, had no effect on the structure, weight, or cystatin content of the exorbital lacrimal gland. After such treatment, however, single large cells with intense staining for cystatin were encountered. Cystatin-like immunoreactive material was also demonstrated in human lacrimal gland using antibodies against human cystatin S. These data suggest the notion that tear cystatins are secreted by the lacrimal glands.     

Evidence for the neuroectodermal origin of the human lacrimal gland

Immunohistochemical staining with antineuronal-specific enolase antibodies showed a positive reaction product in the acini and in the nerves of human major and accessory lacrimal glands. The fibrous tissue interstitium, septae, capsule, and blood vessels reacted negatively. Our findings indicate that the acinar portion of the lacrimal gland, but not the fibrous tissue component, is derived from neuroectoderm. We propose that the acini of the human lacrimal glands develop, not as an ingrowth into the mesenchymal stroma from the surface ectoderm that forms the conjunctiva, but as an outgrowth from the embryonic neuroectoderm, and more specifically, from cells that have migrated from the neural crest.     

Extramedullary hematopoiesis in the lacrimal gland

A 61-year-old woman who carried the diagnosis of chronic myeloid leukemia developed bilateral upper and lower eyelid edema. Orbital magnetic resonance imaging disclosed grossly enlarged lacrimal glands bilaterally. Biopsy of the right lacrimal gland revealed hematopoietic cells and their precursors, and megakaryocytes, consistent with extramedullary hematopoiesis. Extramedullary hematopoiesis can rarely occur in the lacrimal glands of patients with myeloproliferative diseases.     

Carcinoid tumour in the lacrimal gland

A case of carcinoid tumour in the lacrimal gland is described, thought to be a metastasis from a known primary lesion in the mediastinum. The results of light and transmission electron microscopic examination are presented, and the possibility of the lesion representing a second primary tumour discussed.     

Diseases of the lacrimal gland

Experience with the differential diagnosis of lacrimal gland illnesses is limited in daily practice due to their rarity. It is therefore of particular importance to have guidelines for the practitioner by which he can decide on the application of conservative or surgical therapy, and whether it is necessary to take a biopsy to clarify the diagnosis. There is a wide spectrum of possible illnesses which include systemic diseases, inflammatory disorders, neoplastic, benign and malignant tumors. When a pleomorphic adenoma cannot be excluded, biopsy is contraindicated and complete tumor excision with its capsule is necessary to prevent the possibility of malignant transformation and a negative effect on long-term prognosis. In this overview, special interest is placed on the typical clinical aspects and imaging features of lesions of the lacrimal gland fossa, their differential diagnosis and management.     

Cystadenoma of the lacrimal gland

Cystadenoma is a benign cystic tumor predominantly affecting the major and minor salivary glands. We present a case of bilateral cystadenoma of the lacrimal gland, which to the best of our knowledge has never been reported earlier. The patient had slowly increasing, painless, bilateral upper eyelid swelling. On examination, the tumors were multilobulated, mobile and transilluminant. Ultrasonography and CT-scan revealed cystic lesions with multiple septations in the region of both lacrimal fossae. Complete excision of the tumors was performed because of their potential for malignant transformation. The histopathological findings confirmed the diagnosis.     

Differential distribution of neuronal markers and neuropeptides in the human lacrimal gland

Background: The present study was untertaken in an attempt to broaden the spectrum of known neuronal markers and neuropeptides in the main lacrimal gland of the human by light-microscopic immunohistochemistry. Methods: Using antisera against the neuronal markers protein gene product (PGP) and S-100 protein (S-100), the distribution of nerve fibers in the human main lacrimal gland was studied. Vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and tyrosine hydroxylase (TH) were identified by their specific antisera. Results: The nerve fibers are distributed throughout the interstice between the glandular tubules. Associations were also found between nerve fibers and both the interlobular ductal system and blood vessels (mainly arterioles). Within the glandular lobules isolated groups of secretory cells stained positive for S-100 protein. Nerve fibers situated in the glandular interstice between the tubules showed predominantly positive immunoreactions for the neuropeptide VIP, while only very few fibers stained positive for CGRP, NPY and the catecholamine marker TH. Nerve fibers associated with interlobular blood vessels were mainly CGRP and NPY positive and stained only very rarely for VIP. The epithelia of interlobular ducts and excretory ducts were associated with CGRP-immunoreactive nerve fibers. Conclusion: The neuropeptides identified in the lacrimal gland indicate the complexity with which a variety of biologic signals regulate and modulate the lacrimal gland.Presented in part at the Joint European Research Meetings in Ophthalmology and Vision (JERMOV), 15–19 October 1994, Montpellier, France     

Comparison of enzymes of tears, lacrimal gland fluid and lacrimal gland tissue in the rat

A variety of enzymes were identified in rat tears and lacrimal gland fluid. The use of a tapered glass cannula in the opening of the excretory duct was found to be an useful method to collect samples of rat lacrimal gland fluid, i.e., the fluid directly originated from the main excretory duct of the lacrimal gland, uncontaminated by secretions from the Harderian gland and from desquamating conjunctival and corneal epithelial cells. Based upon comparison of the enzyme pattern in tears, lacrimal gland fluid and the lacrimal gland tissue, we concluded that the lacrimal gland is the primary tissue source for peroxidase (POD), amylase (AMY) and total protein in rat tears, while plasminogen activator and lactatedehydrogenase (LDH) may be present in tears primarily as secretion products from other ocular tissue sources. beta-hexosaminidase (beta-hex) is released from the lacrimal gland and from other ocular tissue sources as well.