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Oncocytomas (oxyphil cell adenoma) are rare benign tumours that mainly arise in the glandular epithelia of salivary gland tissue situated within the mucosa of the head and neck (Eglen 1982). This tumour occurs in various organs in the body such as salivary gland, thyroid and accessory thyroid. The first description of an oncocytic lesion involving the ocular adnexa is credited to Radnót (1941), who reported an oncocytic adenomatous hyperplasia of the lacrimal sac. Adnexal oncocytomas are rare, with most reported cases affecting the caruncle, although it has been described in the lacrimal sac, conjuctiva and the lacrimal gland.

We are reporting the case of a 68-year-old male with a 6 month history of a right upper lid protruding lesion with mild discomfort. He had no other symptoms. The ocular examination revealed a 10 mm diameter, deeply situated lesion, on the lateral third of the right upper lid and dilated conjunctival vessels on the underlying area of the conjunctiva. The mass was not adherent to the skin or to the orbital bone. The ocular examination was otherwise normal.

The orbital MRI (Fig. 1) showed a well-defined mass of 16 × 8 × 12 mm, involving the lacrimal gland, with an homogenous signal pattern without invasion of the bone. Fine needle aspiration biopsy disclosed a probable oncocytoma and no atypia was noticed. Complete removal of the tumour was achieved via an anterior orbitotomy. There were no intraoperative or postoperative complications.

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Figure 1.  MR scan of the orbits showing a lesion in the left lacrimal gland area.

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Gross examination showed a rounded, partially encapsulated tumour measuring 10 × 10 × 10 mm. Light microscopic examination showed that the completely excised tumour was composed of large epithelial cells with granular eosinophilic cytoplasm and small nuclei without apparent atypia. These cells formed cords and tubular structures and the overall features were consistent with an oncocytoma. Normal lacrimal gland tissue was present, separated only by a few strands of collagen fibres (Fig. 2).

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Figure 2.  Tumour appearance by light microscopy showing oncocytoma tissue to the left and lacrimal gland tissue to the right separated only by a few loose strands of collagen fibres.

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The tumour cells showed a weak to moderate immunoreactivity for S-100 while the immunoreactivity for the epithelial markers AE1/3 was more distinct.

Poor tear secretion was compensated by use of lubricating eye drops. There were no signs of recurrence of the tumour 2 years after the excision.

Two types of cells are seen in oncocytomas: a columnar-type cell and a polygonal-type cell. These two cell types show different eosinophilic staining of the cytoplasm according to the density of the mitochondria (Rennie 1980). An increase of mitochondria in oncocytes has been interpreted as the result of compensation for the functional abnormality (Hamperl 1962). The details of this phenomenon though are still unknown. As for the origin of the tumour, previous reports indicate that oncocytomas in the lacrimal gland originate from acinar cells (Radnót 1941).

Oncocytomas of the head and neck are relatively rare tumours that have been reported in the salivary glands, nasal cavities, sinuses and ocular adnexae, including the caruncle and the lacrimal sac, while oncocytomas of the lacrimal gland have been reported in only five different patients previously (Calle 2006). There are also two reported cases of oncocytic carcinoma of the lacrimal gland (Calle 2006). The very first report of a lacrimal gland oncocytoma is attributed to Beskid (1959), who described the lesion in a 39-year-old woman. Riedel (1983) is the first and only to describe the tumour in an infant – an 18-month-old African girl – along with a 76-year-old woman. Hartman and colleagues (2003) describe a 72-year-old man with oncocytoma of the lacrimal gland that debuted with proptosis and swelling of the upper lid. In all these patients, as in our case, there was no tumour regrowth after the surgical excision.

Proliferations of oncocytic cells can also show malignant features and become malignant oncocytomas. Riedel (1983) describes 58-year-old and 59-year-old patients with malignant oncocytoma (synonym: oxyphilic adenocarcinoma) of the lacrimal gland with intracranial extension. Despite radical resection and postoperative radiation therapy, both patients died as a result of liver metastases 6 months and 2 years, respectively, after the initial symptoms. An 81-year-old woman reported by Biggs (1977) had a 6 month history of proptosis because of an oncocytic adenocarcinoma of the lacrimal gland. No follow-up information was given by the author. The most recent report is by Calle (2006), who describes a 40-year-old Hispanic woman with an oncocytoma of the lacrimal gland treated with lateral orbitotomy and no tumoral recurrence after 21 months of follow-up.

In summary, oncocytomas of the lacrimal gland are benign, epithelial tumours arising in the ductal cell lining of apocrine glandular structures. They tend to grow slowly and the symptoms can vary from mild lid swelling with no discomfort (as in the case reported here) to proptosis with severe pain. Inflammatory disease represents the main cause of a lacrimal gland mass, but oncocytomas – although very rare – should be included in the differential diagnosis.

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