Immunohistologic properties of benign and malignant mixed tumor of the lacrimal gland

Clinical Implications of Goblet Cells in Dacryoadenosis and Normal Human Lacrimal Glands

PURPOSE

The purpose of this study was to investigate an enlarged dacryoadenotic lacrimal gland and normal lacrimal glands for the presence of goblet cells (mucocytes).

DESIGN

Retrospective clinicopathologic series.

METHODS

An enlarged lacrimal gland (dacryoadenosis) without obvious histopathologic alterations was extensively evaluated histochemically, immunohistochemically, and ultrastructurally to detect the presence of goblet cells and to compare the findings with those in five normal lacrimal glands.

RESULTS

Granular, zymogen-rich pyramidal acinar cells in normal glands predominated over a previously not reported subpopulation of nongranular, pale-staining cells in both dacryoadenotic and normal lacrimal glands. These cells histochemically stained positively with mucicarmine and Alcian blue. Immunohistochemical and electron microscopic evaluations established that there was a displacement or replacement of cytoplasmic gross cystic disease fluid protein-15 and CK 7-positive tonofilaments in the pale acinar cells by myriad mucus granules. The goblet cells constituted approximately 2% of the normal acinar cells and 5% of dacryoadenotic acinar cells. A depletion of myoepithelial cells and ectopic intra-acinar ductular cells were also observed in dacryoadenosis.

CONCLUSION

Dacryoadenosis is caused by an increase in the number of acini without individual acinar cell hyperplasia. A normal cytologic feature of the lacrimal gland is the presence of acinar goblet cells that had been long overlooked; they are increased in number in dacryoadenosis. Intra-acinar ductular cells and the scattered loss of myoepithelial cells are other abnormalities in dacryoadenosis. The presence of lacrimal gland goblet cells may have physiologic implications for the precorneal tear film and its derangements as well as for the histogenesis of mucus-producing carcinomas.

Tumors of the lacrimal gland

Tumors of the lacrimal gland comprise a wide spectrum, of which the most common demonstrate epithelial and lymphoid differentiation. The diagnosis of lacrimal gland tumors depends primarily on histological evaluation, as do the choice of treatment and prognosis. For some lacrimal gland neoplasms, such as adenoid cystic carcinoma, the outlook is grave. Optimal treatment for several lacrimal gland tumors is also a matter of controversy. However, recent progress has been made in the molecular and genetic understanding of tumorigenesis for such lesions. This article presents an overview of the histopathology of lacrimal gland tumors, together with their epidemiological features, clinical characteristics, and treatment strategies.

Pleomorphic Adenoma With Prominent Clear Cell Myoepithelioma Component of the Lacrimal Gland

A case of a pleomorphic adenoma of the lacrimal gland with a prominent clear cell myoepitheliomatous component was reported. An 81-year-old Caucasian woman experienced a 2-month history of right supraorbital swelling and proptosis. Excisional biopsy revealed a multicomponent lesion including a stromal component featuring glandular structures made of small epithelioid and spindle cells and a trabecular component with small islands of vacuolated cells, displaced nuclei, and clear cytoplasm. Immunohistochemical analysis revealed strong cytokeratin AE1/3 reactivity and focal smooth muscle actin positivity. The pathologic findings including immunohistochemistry results were consistent with a pleomorphic adenoma with prominent clear cell myoepithelioma component.

Tumours of the lacrimal gland. Epidemiological, clinical and genetic characteristics

Tumours of the lacrimal gland are rare, but the prognosis may be grave. To date, no population-based incidence and distribution data on lacrimal gland tumours exist. In addition, almost nothing is known about the genetic profile of epithelial tumours of the lacrimal gland. We collected specimens and clinical files on all biopsied lacrimal gland lesions in Denmark over a 34-year period and re-evaluated the diagnosis to provide updated population-based incidence rates and epidemiological characteristics. Clinical data regarding symptoms, clinical examinations, treatment and follow-up were collected for patients with adenoid cystic carcinoma (ACC), pleomorphic adenoma (PA), carcinoma ex pleomorphic adenoma (Ca-ex-PA) and mucoepidermoid carcinoma (MEC). Using RT-PCR, FISH, immunohistochemistry, Q-PCR and high-resolution array-based comparative genomic hybridization (arrayCGH) we explored the genetic characteristics including copy number alterations (CNA) in ACC, PA, Ca-ex-PA and MEC. The incidence of biopsied lacrimal gland lesions was 1.3/1,000,000/year, and ~50% were neoplastic lesions. Of these, 55% were malignant tumours with epithelial tumours as the most frequent. The overall incidence was increasing, and this was caused by an increase in biopsied non-neoplastic lesions. We found that 10/14 ACCs either expressed the MYB-NFIB fusion gene and/or had rearrangements of MYB. All ACCs expressed the MYB protein. ACC was characterized by recurrent copy number losses involving 6q, 12q and 17q and gains involving 19q, 8q and 11q. ArrayCGH revealed an apparently normal genomic profile in 11/19 PAs. The remaining 8 PAs had recurrent copy number losses involving 1p, 6q, 8q and 13q and gain involving 9p. PA expressed PLAG1 in all tumours whereas only 2/29 tumours expressed HMGA2. Ca-ex-PA was characterized by recurrent copy number gain involving 22q. PLAG1 was expressed in 3/5 Ca-ex-PA whereas none of these tumours expressed HMGA2. MEC expressed the CRTC1-MAML2, and this fusion was found to be tumour-specific for lacrimal gland MEC. In conclusion, lacrimal gland lesions that require pathological evaluation are rare in the Danish population, and the incidence rate of biopsied benign lesions is increasing. Epithelial tumours of the lacrimal gland are molecularly very similar to their salivary gland counterparts in the expression of the tumour-specific fusion genes and in their genomic imbalances as demonstrated by arrayCGH. MYB-NFIB is a useful biomarker for ACC and MYB, and its downstream target genes may be potential therapeutic targets for these tumours.

Extra-major salivary gland pleomorphic adenoma of the head and neck: a 10-year experience and review of the literature

Pleomorphic adenomas, or benign mixed tumors, make up 65% of all salivary gland tumors. They also can be found as solid tumors in other parts of the head and neck region, such as the auditory canal, the eyelids, and the orbital area. In this study, we investigated extra-major salivary gland pleomorphic adenomas of the head and neck region retrospectively at a tertiary care center. Between March 1998 and June 2009, 37 patients underwent primary surgery for extra-major salivary gland pleomorphic adenoma of the head and neck. The duration of symptoms, radiographic findings, operative procedures, and pathologic findings were documented. Of the 37 patients enrolled, 22 were male and 15 were female, with a median age of 57 years. Tumors were found in the soft palate, hard palate, nasopharynx, orbital area, trachea, buccal mucosa, cheek, nasal septum, upper lip, lower eyelid, and external auditory canal. Cellular variant of the pleomorphic adenoma was found in four patients, while the remaining patients presented with the classic variant. No myxoid subgroup was noted in our study. Carcinoma ex pleomorphic adenoma was observed only in one patient for whom radical surgery was performed. Twenty-eight patients (76%) had long-term follow-ups, with the average follow-up period being 4.5 years. Local recurrence was observed in three patients, and they underwent revision surgery during the follow-up period. Our results indicate that extra-major salivary gland pleomorphic adenomas are most commonly found in the soft palate. Wide excision was the treatment of choice, although its efficacy might be compromised with cosmetics and functional structures of the head and neck. Therefore, long-term follow-up of patients is necessary.

Pleomorphic Adenoma Arising in an Accessory Lacrimal Gland of Wolfring

PURPOSE

To describe a patient with pleomorphic adenoma arising in an accessory lacrimal gland of Wolfring in the lower lid and to illustrate the immunohistochemical and molecular cytogenetics.

DESIGN

Single interventional case report.

METHODS

A 62-year-old man presented with a 20-year history of a painless slowly growing mass at the temporal part of the right lower eyelid. Histological, immunohistochemical, and fluorescence in situ hybridization studies of the excised tumor were performed.

RESULTS

Histological evaluation showed many glandular elements embedded in a myxoid stroma. The tumor was situated beneath an area of a normal accessory lacrimal gland of Wolfring and in close association with normal meibomian glands. Myoepithelial tumor cells in the myxoid stroma reacted strongly with an antibody against glial fibrillary acidic protein, which did not bind to normal lacrimal gland tissue. Tumor cells with both epithelial and myoepithelial morphologies reacted positively for both pleomorphic adenoma gene-1 and high-mobility group A2 proteins. Fluorescence in situ hybridization analysis showed no evidence of clonal translocations or numerical abnormalities involving chromosome 8 or 12.

CONCLUSIONS

Pleomorphic adenoma of the accessory lacrimal gland is an exceedingly rare tumor of the ocular adnexa. Glial fibrillary acidic protein seems to be a tumor-associated antigen. Genetically, this case of pleomorphic adenoma arising from an accessory lacrimal gland of Wolfring is identical with those originating from salivary glands.

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.

Myoepithelioma of the lacrimal gland: report of a case with spindle cell morphology

The case is described of a 23-year-old female patient presenting with unilateral proptosis, headaches, and transient epiphora. Surgery revealed an encapsulated tumour composed exclusively of spindle-shaped cells within a richly vascularised myxoid stroma. Immunohistochemical staining showed focal positivity for smooth muscle actin, vimentin, and glial fibrillary acidic protein. These combined findings are interpreted as providing evidence of a myoepithelioma, which may be regarded as a monomorphic adenoma consisting solely of myoepithelial cells. To our knowledge this is only the second report of such a tumour in the lacrimal gland.

Pleomorphic adenoma of the lacrimal gland

To reduce the risk of recurrence and malignant transformation, pleomorphic adenomas of the lacrimal gland should be removed intact, without prior biopsy. Seventy one of the 78 patients in this series were referred without previous surgery, and, on clinical or radiological evidence, 63 (89%) tumours were correctly diagnosed and totally excised, with preservation of a margin of the surrounding normal tissue. Sixty three patients had tumour within the body of the gland and 55 (84%) had radiological signs or satisfied clinical criteria for pleomorphic adenoma that we suggested previously; that is, over 1 year of symptoms and absence of pain. Eight (16%) orbital lobe tumours were misdiagnosed preoperatively and biopsied; in all these patients symptoms had been present for less than 1 year, and four patients had pain. Eight patients with tumours arising in the palpebral lobe had a short history of an upper lid mass, and their tumours were excised without biopsy. With the surgical techniques described in this paper, there has been no recurrence of tumour in patients with follow-up as long as 21 years. A modification of surgical technique, with preservation of the palpebral lobe of the gland, has reduced the incidence of postoperative dry eye and distortion of the upper eyelid.