Diagnostic pitfall: primary myoepithelial carcinoma of the lacrimal gland, case report and literature review

Abstract

BackgroundIn lacrimal gland, lymphomas and inflammatory lesions predominate. Primary epithelial tumours represent less than 30% of lacrimal gland lesions. Myoepithelial carcinoma of lacrimal gland is rare. To the best of our knowledge, only nine cases have been reported in the literature. This lesion presents diagnostic difficulties: non-specific clinical and radiological findings and histological polymorphism. This is well illustrated by the diagnostic pathology errors described in the literature.We report a new case of lacrimal myoepithelial carcinoma with a review of others published cases to try to assess clinico-pathological features and outcome whenever possible of this rare tumour.Case presentationAn 80-year-old Arabian female presented with a 2-month history of swelling over the right eyebrow, pain, proptosis of the right eye and diplopia. Computed tomography demonstrated an ill-defined, homogeneous, contrast-enhancing mass attached to the medial rectus. A biopsy was performed. Microscopic examination showed malignant spindle cells tumour, most consistently to sarcoma or sarcomatoid carcinoma. Immunohistochemical study was not possible because neoplastic material has been exhausted. Subsequently, total exenteration of the right orbit was performed. Immunohistochemical study revealed diffuse positive staining for pancytokeratin AE1/AE3, epithelial membrane antigen (EMA) and smooth muscle actin (SMA) and focal positivity for S100 protein. The lesion was immunonegative for desmin, h-cladesmon, CD34, Melan-A and HMB-45. The tumour was extending to the surgical margins. The patient was lost to follow-up until she developed local tumour progression 3 months after removal. The patient was again lost to follow-up and therefore did not receive any other treatment in our hospital.ConclusionWe present this rare tumour with an unusual location. The use of a complete immunohistochemical panel with epithelial and myoepithelial markers positivity helped us for classification of this poorly differentiated tumour.

Myoepithelial carcinoma of lacrimal gland in HIV patient: A rare case

“…Mahdi et al Mentioned the symptoms that are usually complained of by patients with myoepithelial lacrimal gland carcinoma in the form of proptosis, decreased visual acuity, a mass in the superolateral area, pain around the orbit and diplopia. 6 The patient in this case report showed symptoms of a lump on the eyelid and pushing the eyeball. Visual acuity decreases slowly, and complaints of double vision are accompanied by pain.…”

“…Infiltrative and destructive growth is the main histological feature associated with malignant behavior. 6 Anatomical, pathological examination in this patient showed a well-defined tumor mass with some parts appearing infiltrative into the surrounding stroma. The tumor cells are solidly arranged.…”

“…Complete immunohistochemical examination with positive epithelial and myoepithelial markers helps classify tumors of the poorly differentiated type. 6 The case report reported by Mahdi et al mentioned that no distant metastases were found in a lacrimal gland epithelial carcinoma patient. Three cases were said to have local or locoregional recurrence diagnosed between 3 to 24 months.…”

“…It was concluded that the outward pattern in this patient indicated that the tumor cells were of epithelial origin (carcinoma). 6 Management such as resection is the primary therapy in cases of myoepithelial carcinoma. The type of resection can be wide local excision or orbital exenteration.…”

A series Cases study of Carcinomas derived from myoepithelial cells in head and neck regions

“…These myoepithelial cell differentiated malignancy were indistinguishable, and immunohistochemical results were often required in the pathological diagnosis of these diseases. S-100 protein, vimentin and cytokeratin (CK) were the most sensitive markers of MEC [14].Double-layer tubular structure of EMC could be identi ed by CK staining for glandular epithelial cells in the inner layer, and by S-100 and smooth muscle actin (SMA) antibody staining for clear outer layer of myoepithelial cells [15].AdCC also presented a tubular structure composed of two layers of cells. Unlike EMC, S-100 protein staining was only positive in the inner layer of AdCC [16].…”