Myoepithelial carcinoma of the orbit: a clinicopathological and histopathological study

Abstract

Two cases of invasive myoepithelial carcinoma arising from the paranasal sinuses and invading the orbit are presented. Patient 1, a 53-year-old man, had a 3-month history of proptosis, pain and epiphora of the right eye. The second patient, a 24-year-old man, had for a week been complaining of protrusion of his left eye and of orbital pain. Computed tomography scan and magnetic resonance imaging revealed tumour masses in the frontal, ethmoidal and maxillary sinuses with invasion of the orbit and the frontal lobe. Biopsies from both cases showed spindle and epithelioid tumour cells. Mitotic figures were frequent. Immunohistochemical staining showed positive reaction for bcl-2, calponin, cytokeratins, CD99, S100, muscle-specific antigen, smooth muscle antigen and vimentin. The Ki-67 index was between 30-50% and 5-25%, respectively. Ultrastructurally, intermediate filaments, perinuclear tonofilaments and desmosomes were present. Based on these findings, a diagnosis of myoepithelial carcinoma of mixed cell type in both cases was evident. Both patients died shortly after the diagnosis was made even though both underwent radical surgery. Myoepithelial carcinoma of the paranasal sinuses is very rare and only six cases have been reported previously. We present the first two cases of myoepithelial carcinoma in the paranasal sinuses with invasion of the orbit. This is also the first report of myoepithelial carcinoma arising in the ethmoidal sinus.

Myoepithelioma of the Orbital Apex and Middle Cranial Fossa: Case Report and Review of the Literature

“…6 Myoepithelial tumours may occur in the scalp, orbit, sella region, cerebellopontine angle, lacrimal and salivary glands, sinuses, nasopharynx, masticator space, palate, and larynx (Table 1). 1,4,5,[7][8][9][10][11][12][13] Other sites where myoepithelial neoplasms have been reported include the trunk, viscera, and limbs. 1,4 At a genetic level, Ewing sarcoma breakpoint region (ESRW-1) locus and pleomorphic adenoma gene (PLAG-1) locus mutations may be seen; the ESRW-1 mutation is more commonly seen in myoepithelial tumours of soft tissue origin and the PLAG-1 mutation in myoepithelial tumours of glandular origin.…”

“…[14][15][16][17][18][19] In general, these are slow growing, benign, or low-grade tumours, but malignant lesions, known as myoepithelial carcinomas, are also reported. 1,[3][4][5]11,13,20,21 Myoepithelial carcinomas are more aggressive tumours but are even rarer than the low-grade myoepithelial neoplasm. They tend to invade surrounding tissues and reach a large size at presentation.…”

Anaplastic Myoepithelial Carcinoma of the Sinonasal Tract: an Underrecognized Salivary-Type Tumor Among the Sinonasal Small Round Blue Cell Malignancies? Report of One Case and a Review of the Literature

“…Although it should be noted that two patients with low-grade tumors developed metastasis, of which one patient succumbed to the disease. MECA have, besides the mammary gland, also been described in the nasopharynx [4,5], lung [6], larynx [7,8], the infratemporal fossa [9], orbit [10] and skin [11][12][13].…”

Primary Myoepithelial Carcinoma of the Conjunctiva

“…It is known from a handful of ophthalmic case reports that primary myoepithelial tumours (myoepitheliomas and myoepithelial carcinomas) can arise from the eyelid skin, lacrimal gland, and orbit [3-9]. In dogs the third eyelid can give rise to lesions that resemble myoepithelial tumours [11, 12].…”

“…There are many other tumours in which myoepithelial cells are a component, of which the example par excellence is pleomorphic adenoma of the salivary and lacrimal glands. While a handful of case reports have documented primary myoepithelial tumour or myoepithelial-rich components in other tumours in the orbit, lacrimal gland, and eyelid [3-9], there have been no published cases of primary myoepithelial tumours arising in the conjunctiva. We document an unusual conjunctival primary myoepithelial carcinoma of the bulbar conjunctiva in a 38-year-old woman.…”