Superficial epithelioid schwannoma presenting as a subcutaneous upper eyelid mass

Pathology of eyelid tumors

The eyelids are composed of four layers: skin and subcutaneous tissue including its adnexa, striated muscle, tarsus with the meibomian glands, and the palpebral conjunctiva. Benign and malignant tumors can arise from each of the eyelid layers. Most eyelid tumors are of cutaneous origin, mostly epidermal, which can be divided into epithelial and melanocytic tumors. Benign epithelial lesions, cystic lesions, and benign melanocytic lesions are very common. The most common malignant eyelid tumors are basal cell carcinoma in Caucasians and sebaceous gland carcinoma in Asians. Adnexal and stromal tumors are less frequent. The present review describes the more important eyelid tumors according to the following groups: Benign and malignant epithelial tumors, benign and malignant melanocytic tumors, benign and malignant adnexal tumors, stromal eyelid tumors, lymphoproliferative and metastatic tumors, other rare eyelid tumors, and inflammatory and infections lesions that simulate neoplasms.

Isolated Schwannoma of the Upper Eyelid Margin in a 50-year-old Male

Schwannomas (neurilemmomas) are benign neurogenic tumours of peripheral nerves. They originate from Schwann cells, which form the neural sheath. Although Schwannomas and neurofibromas are the most common primary peripheral nerve tumours, Schwannomas are rarely observed in ophthalmic areas. When they occur, ocular Schwannomas are usually located in the orbit, uveal tract and conjunctiva. Isolated eyelid Schwannomas are reported infrequently. Herein, we describe a case of eyelid Schwannoma in a 50-year-old man. The diagnosis of Schwannoma was made after the eyelid mass was removed by excisional biopsy, so this entity should be included in the differential diagnosis of eyelid margin tumours.

Schwannoma of upper eyelid: A rare differential diagnosis of eyelid swellings

Schwannoma is a relatively rare benign tumour of peripheral nerve origin. The occurrence of Schwannoma in eyelid is extremely rare. As per our knowledge, only 11 such cases have been reported in the literature so far. We present a case of a 40-year-old man who presented to us with a 2-year history of slowly enlarging, painless mass in his left upper lid with resultant progressive ptosis. Ocular examination was suggestive of a firm, non-tender nodule of size 2 × 1.5 × 1 cm on the left upper lid. The mass was non-adherent to the skin or the underlying tissue. The eyelid skin and conjunctiva were indurated and signs of inflammation were present. The lateral part of eyelid showed presence of an ulcer and the lid function was severely hampered. Provisional clinical diagnosis was that of an eyelid malignancy. With this in mind, the medial part of the lid was excised and reconstructed using a tarso-conjunctival flap from the lower eyelid in conjunction with a skin graft. The histopathology and immunohistochemistry established the diagnosis of Schwannoma. We recommend that Schwannoma be considered in the differential diagnosis of well-circumscribed eyelid swellings.

Cystic schwannoma of eyelid in an Indian male: a rare presentation

Eyelid schwannoma (neurilemmomas) is an extremely rare, benign neoplasm. A case of Cystic Schwannoma in eyelid of a young adult is reported. A 19-year-old male presented with a firm-nodular painless lesion, 3.5 cms in diameter, located on the left lower eyelid for the last 2 years. The lesion was surgically excised. Histopathological diagnosis of cystic schwannoma was made. Immunohistochemistry revealed strong S-100 positivity indicative of Schwann cell origin. No recurrance was seen after a follow up of 1 year.

Plexiform Epithelioid Schwannoma:

Epithelioid schwannoma is rare but may pose a challenge in histopathologic diagnosis. In the present report, we describe a plexiform variant of epithelioid schwannoma in the skin of the breast of a 47-year-old woman.

Eyelid schwannoma in a male adult

Schwannomas (neurilemmomas) are benign tumours of peripheral nerves arising from Schwann cells. These tumours along with neurofibromas form the two most common primary peripheral nerve tumours. Solitary lesions can occur sporadically in the general population but multiple neurofibromas are distinctive feature of neurofibromatosis type 1 and bilateral acoustic schwannomas are a feature of neurofibromatosis type 2. Schwannomas of ophthalmic interest are rare although they have been reported in relation to the orbit, and infrequently uveal tract and conjunctiva. Isolated eyelid schwannomas appear infrequent; only four cases in adults and one in a child in the published literature have been found. Herein, a case of eyelid schwannoma in a 53-year-old man is described.

Benign Epithelioid Peripheral Nerve Sheath Tumors of the Soft Tissues

Benign epithelioid peripheral nerve sheath tumors (BEPNSTs) have not been fully characterized, and their relationship to conventional schwannoma and neurofibroma has not been satisfactorily established. Herein, we detail the clinicopathologic features of 33 examples of BEPNST. The study included 22 females and 11 males ranging in age from 2 to 68 years (median, 31.5 years). Only one patient probably has neurofibromatosis type 1. The tumors were predominantly dermal/subcutaneous in location (85%) and involved the lower limb (n=15), upper limb (n=11), trunk (n=4), and head/neck (n=3). The lesions ranged in size from 0.3 to 6.8 cm (median, 1.1 cm). Microscopically, the tumors were generally well-circumscribed, uninodular, or multinodular masses. Twenty-six lesions were encapsulated. Tumors consisted of trabeculae, loosely arranged nodules, and cohesive nests of epithelioid tumor cells immersed in collagenous, myxohyaline, or chiefly myxoid stroma. A bland spindled cell component comprising 5% to 40% of the tumor was noted in 15 cases. Mitotic activity ranged from 0 to 6 mitoses/50 high power fields (mean, 1.5 mitoses/50 high power fields) with no abnormal division figures identified. Five lesions were considered atypical based on presence of focal nuclear/nucleolar enlargement and hyperchromasia. Immunohistochemical reactivity for Schwann cell-related markers in tumor cells included S-100 protein (20 of 20 cases), collagen type IV (10 of 10), laminin (8 of 8), nerve growth factor receptor, p75(7 of 8), CD57 (6 of 9), and glial fibrillary acidic protein (8 of 15). CD34-positive fibroblast-like cells were identified in all 12 neoplasms tested. Anti-epithelial membrane antigen highlighted perineurial cells in 9 of the 11 encapsulated tumors. Anti-neurofilament protein did not identify intralesional neuraxons in the 10 tumors evaluated. Eighteen tumors were subtyped as epithelioid neurofibromas. The remaining 15 cases showed some histologic features suggestive of schwannoma, but their uniform cellularity, absence of nuclear palisading, and presence of a significant CD34-positive spindled cell population in 5 cases led to their classification as "BEPNST of indeterminate histogenesis." Evaluation for loss of heterozygosity in 2 cases demonstrated deletion of genetic material on chromosome 22q and 17q involving NF2 and NF1 loci. However, sequencing of NF2 coding sequences revealed no mutations. Follow-up for 18 patients (median interval, 13.5 years), including 4 patients with tumors exhibiting cytologic atypia, revealed a nondestructive recurrence or persistent disease in 3 patients whose tumors lacked atypia, but no evidence of metastatic spread or tumor-related death. BEPNSTs are usually small neoplasms located in superficial soft tissue and have an excellent prognosis after complete local excision. Accurate subclassification of some of these lesions is difficult based on currently available techniques.

A forehead mass present for 53 years after trauma in childhood

A 60-year-old man developed a mass on his forehead in his childhood. Histologic examination revealed a subcutaneous encapsulated cellular neoplasm consisting of mostly polygonal epithelioid cells, with abundant amphophilic cytoplasm and pleomorphic nuclei. There was one focal area of spindle cells. Numerous blood vessels of various sizes, small vacuoles and eosinophilic hyalinized material were also present. The morphologic features of the neoplasm did not fit with the typical features of any recognized pathologic entity. The subsequent immunohistochemical and electron microscopical evidence supported the diagnosis of epithelioid schwannoma, a rare variant of schwannoma that has not been reported in oral and maxillofacial pathology publications. The purpose of this report is to document a case and increase the awareness of this entity.

Cutaneous epithelioid schwannomas: a rare variant of a benign peripheral nerve sheath tumor

Although benign epithelioid peripheral nerve sheath tumors have been described, they are rare, and benign epithelioid schwannomas have not yet been established as a specific histologic variant. We present four cases of tumors which we believe would meet criteria to be classified as benign epithelioid schwannomas. Biopsy specimens obtained from four different patients were examined with routine and immunohistochemical staining. All the tumors were well-circumscribed lesions that were surrounded by a capsule containing EMA-positive cells. The cellular component was composed of epithelioid cells, in which there was a lack of mitotic activity. Immunohistochemical studies showed the tumor cells were S-100 protein and Leu 7 positive and HMB-45 negative. In addition, type IV collagen encircled individual cells within the tumor, indicating a continuous basal lamina. We report a group of cutaneous epithelioid schwannomas. Although the presence of such tumors is not unexpected, this diagnosis may not be initially considered because of this rare cytologic feature.