Clinicopathological features of peripheral nerve sheath tumors involving the eye and ocular adnexa

Solitary neurofibroma confined to inferior rectus muscle tendon: a case report

The present study reports a case of solitary neurofibroma attached to the Inferior Rectus (IR) muscle tendon in a 24-year-old healthy woman and reviews the relevant literature regarding the clinical presentation, diagnosis, and management of this uncommon tumor. The patient underwent successful surgical resection of the tumor, leading to the resolution of associated symptoms (left lower eyelid protrusion and redness). Pathological examination confirmed the diagnosis of neurofibroma based on characteristic histopathological and immunohistochemical markers. This case report underscores the rarity of solitary neurofibromas and primary neoplasms of orbit and ocular adnexa. We also discuss the background of solitary neurofibromas originating from orbit and ocular adnexa. The successful management of this case through surgical resection highlights the importance of accurate diagnosis and tailored treatment strategies. To the best of our knowledge, this is the first reported solitary neurofibroma confined solely to the IR tendon.

Plexiform Schwannoma of the Eyelid

Plexiform schwannoma of the lacrimal gland of the palpebral lobe has not been previously described. This 41-year-old male presented with a 2-year history of a left upper eyelid mass and associated regional irritation. MRI of the head and orbits confirmed a left superolateral multinodular mass centered on the palpebral lobe of the left lacrimal gland. Excision revealed a schwannoma of the plexiform subtype.

A case of eyelid neuroma with recurrent ptosis

Purpose

We report a rare case of eyelid neuroma, discovered nine years after external levator advancement, presenting with recalcitrant ocular foreign body sensation and pain, persistent corneal epithelial defect, followed by corneal scarring, and ptosis.

Observations

An 85-year-old man with a history of multiple skin cancers presented with left ptosis, epiphora and recalcitrant eye pain. Nine years prior to presentation, he underwent excision of melanoma in situ of the left forehead, followed by simultaneous forehead reconstruction and left external ptosis repair. At presentation, he had left ptosis and left superior corneal scarring. Eversion of the eyelid demonstrated the presence of a nodule at the superior border of the tarsus. The patient underwent simultaneous excisional biopsy of the lesion and posterior ptosis repair by Müller muscle conjunctival resection (MMCR). He experienced postoperative resolution of pain, ptosis and epiphora. Histopathologic examination demonstrated the presence of a foreign body granuloma alongside a neuroma.

Conclusions

This case highlights the importance of thorough eyelid exam in individuals with ocular surface disease. We review herein the pathophysiology and histopathology of eyelid neuroma.

Miniature Palpebral Plexiform Neurofibroma in Neurofibromatosis Type 2

A 27-year-old woman with well-documented neurofibromatosis 2 developed a soft, painless, nodular lesion on the skin surface of the left upper eyelid over 2 years. Following excision, histopathology revealed a plexiform neurofibroma with intradermal nodules comprised of benign round and spindle cells that reacted diffusely with immunohistochemical stains SOX-10 and S100. A subset showed focal reactivity for neurofilament and CD34. A perineurium surrounded each nodule with cells staining positively for markers EMA (epithelial membrane antigen) and GLUT1 (glucose transporter 1). Plexiform neurofibromas are rare tumors that occur in 5%-15% of patients with neurofibromatosis 1. Cutaneous abnormalities in neurofibromatosis 2 have not been widely studied although reports have described schwannomas, plexiform schwannomas, and occasional neurofibromas. Plexiform neurofibromas in neurofibromatosis 2 have rarely been illustrated and the current case represents a unique bona fide eyelid example to date.

Primary lacrimal gland plexiform neurofibroma: a case report and review of the literature

Neurofibromatosis type 1 (NF1) affects cell growth in neural tissues, resulting in neurofibromas of the internal organs, peripheral nerves and/or autonomic nerves. We describe a highly unusual case of plexiform neurofibroma presenting with lacrimal gland enlargement in an 18 year old male, which led to a diagnosis of NF1.

Imaging characteristics of orbital peripheral nerve sheath tumors: Analysis of 34 cases

BACKGROUND

Peripheral nerve sheath tumors (PNSTs), a rare group of neoplasms in the orbit, comprise only 4% of all orbital tumors. At present, there are very few studies detailing the features of these tumors identified using imaging technology.

AIM

To compare the differences in location, morphology, magnetic resonance imaging (MRI) signal intensity/computed tomography (CT) value, and enhancement degree of tumors of different pathological PNSTs types.

METHODS

Clinical, pathological, CT, and MRI data were analyzed retrospectively in 34 patients with periorbital sheath tumors diagnosed using histopathology from January 2013 to August 2021.

RESULTS

Among 34 cases of orbital peripheral nerve sheath tumors, 21 were schwannomas, 12 were neurofibromas, and 1 was a plexiform neurofibroma. Common clinical symptoms presented by patients with these types of tumors include eyelid swelling, exophthalmos, and limited eye movement. Schwannomas mostly occur in the intramuscular space with small tumor volume and rare bone involvement. Neurofibromas develop in the extrapyramidal space with larger tumor volume and more bone involvement. Radiologically, schwannomas and neurofibromas are characterized by regular morphology and uneven density and signal. One case of plexiform neurofibroma showed tortuous and diffuse growth along the nerve, with a worm-like appearance on imaging.

CONCLUSION

Different pathological types of orbital peripheral nerve sheath tumors have unique imaging characteristics. Comprehensive consideration of the patient's clinical and imaging manifestations is of great value in the diagnosis of orbital peripheral nerve sheath tumors.

Granular Cell Tumor of the Orbit: Review of the Literature and a Proposed Treatment Modality

PURPOSE

To document a unique case of granular cell tumor of the orbit, located lateral to and abutting the optic nerve, that benefited from treatment with proton beam irradiation, with a comprehensive review of the literature on granular cell tumor of the orbit.

METHODS

Clinicopathologic case report with detailed imaging features and histopathologic and immunohistochemical evaluation for cytoplasmic tumor biomarkers differentiating granular cell tumor (GCT) from it mimicking lesions with relevant literature citations. The authors reviewed 20 cases of orbital GCT from 2011 to 2020 in addition to 40 cases from 1948 to 2011 and included a summary of imaging and clinical features, outcomes, and recommended treatment modalities.

RESULTS

A 32-year-old man with 1-year history of left retrobulbar pain and diplopia on lateral gaze, intermittent left eyelid swelling, and a tonic left pupil was found to have a fusiform intraconal mass extending toward the orbital apex and abutting the optic nerve. Histopathologic and immunohistochemical investigations collectively supplied data diagnostic of a GCT with an initial low proliferation rate. GCT is a soft tissue neoplasm that originates in the nervous system and can occur anywhere in the body. This enhancing tumor is isointense to gray matter on T1-weighted MRI, hypointense on T2. After an incisional biopsy, the patient's symptoms persisted, and follow-up imaging several months later revealed further growth of the mass. The impossibility of complete surgical removal prompted the decision to treat with proton beam radiation therapy, which resulted in substantial regression in the size of the residual tumor. Most frequently involving the inferior rectus muscle (42%), orbital GCT is usually benign with only 4 reported cases of malignant orbital GCT (7%). Wide surgical resection with complete removal is usually curative for benign orbital GCT, and proton beam radiation therapy can aid in tumor shrinkage.

CONCLUSIONS

GCT should be considered in the differential diagnosis when encountering patients with mass lesions involving the extraocular muscles, peripheral nerves, or less frequently, the optic nerve or orbital apex. Immunohistochemical analysis of biopsied tissue is required for the definitive diagnosis of GCT. Consideration of adjuvant therapies such as proton beam radiation therapy may be appropriate in cases of incomplete surgical resection of benign GCT. Proton beam radiation therapy can be an excellent therapeutic option for symptomatic relief and residual tumor size reduction with an acceptable toxicity profile.

Orbital schwannoma management: a case report, literature review, and potential paradigm shift

PURPOSE

To present a case of orbital schwannoma and assess the literature on treatment modalities.

METHODS

A MEDLINE literature search for cases of orbital schwannomas was performed using the PubMed search tool using the search terms "orbital schwannoma" and "orbital neurilemmoma." Papers were included if they were peer-reviewed, published in English, discussed management, and included the search terms. Each article was rated using the scale developed by the British Centre for Evidence-Based Medicine. In addition, we present a case report of an orbital schwannoma.

RESULTS

A total of 428 articles were found. 102 met the criteria for inclusion. Only two articles met Level 1 evidence and 16 were important to the clinical care process. We report a case of a biopsy-proven orbital schwannoma managed conservatively with observation over a 4-year period due to risk of cosmetic disfigurement with tumor removal. There has been no change in tumor size and no associated complications during follow up.

CONCLUSIONS

There is a paucity of data on the natural history of orbital schwannomas. Based on our review of the literature, we recommend observation for asymptomatic or minimally symptomatic orbital schwannomas with minimal growth over an extended period of time. For rapidly growing tumors or large tumors affecting key structures causing visual loss, diplopia, aesthetic disfigurement, or patient discomfort, a more aggressive approach may be necessary.

RNA-sequencing highlights differential regulated pathways involved in cell cycle and inflammation in orbitofacial neurofibromas

Although most commonly benign, neurofibromas (NFs) can have devastating functional and cosmetic effects in addition to the possibility of malignant transformation. Orbitofacial NFs, in particular, may cause progressive, disfiguring tumors of the lid, brow, temple, face, and orbit, and clinical evidence suggests that they may have increased local aggressiveness compared to NFs developing at other sites. The purpose of this study was to identify biological differences between orbitofacial NFs and those occurring at other anatomic sites. We performed RNA-sequencing in orbitofacial (n = 10) and non-orbitofacial (n = 9) NFs. Differential gene expression analysis demonstrated that a variety of gene sets including genes involved in cell proliferation, interferon, and immune-related pathways were enriched in orbitofacial NF. Comparisons with publicly available databases of various Schwann cell tumors and malignant peripheral nerve sheath tumor (MPNST) revealed a significant overlap of differentially expressed genes between orbitofacial versus non-orbitofacial NF and plexiform NF versus MPNST. In summary, we identified gene expression differences between orbitofacial NF and NFs occurring at other locations. Further investigation may be warranted, given that orbitofacial NF are notoriously difficult to treat and associated with disproportionate morbidity.

The clinico-pathologic profile of primary and recurrent orbital/periorbital plexiform neurofibromas (OPPN)

To evaluate and compare the clinical and histopathological profile of primary and recurrent orbital-periorbital plexiform neurofibromas (OPPN) in patients with neurofibromatosis type 1. We retrospectively evaluated 43 primary or recurrent neurofibroma (NF) specimens from 26 patients (2002 to 2018) at the King Khaled Eye Specialist Hospital, Saudi Arabia. Demographics, clinical presentation, and surgical intervention data were collected. Histopathological specimens were studied with hematoxylin-eosin, Alcian blue, and immunohistochemical markers; S-100, CD44, CD117, smooth muscle actin (SMA), neurofilament, and Ki-67. Of the 43 NFs specimens, 20 were primary and 23 recurrent tumors. For primary NF, the ratio of plexiform to the diffuse type was 13:7, however in recurrent tumors was 3:8 after the first recurrence, and 1:5 after multiple recurrences. Of the 17 patients with primary tumors that had paired recurrent tumors, 12/17 (70.6%) primary NFs were plexiform and 5/17 (29.4%) were diffuse. However, when tumors recurred, 13/17 tumors (76.5%) were diffuse and only 4/17 tumors (23.5%) had a plexiform pattern. The odds of a tumor having a diffuse pattern in recurrent NF was significantly higher than the plexiform pattern [OR = 7.8 (95% confidence interval 1.69:36.1) P = 0.008]. Primary plexiform NFs underwent an excision at a significantly younger age than the diffuse type. Recurrent NFs had significantly higher CD44, CD117, and neurofilament labeling (P = 0.02, P = 0.01 and P<0.001 respectively) but had significantly decreased Alcian blue, and S-100 labeling (P = 0.03, and P = 0.02 respectively) compared to primary tumors. SMA and Ki-67 proliferation index were not different between primary and recurrent NFs (P = 0.86, and P = 0.3 respectively). There appears to be a high risk for primary plexiform NFs to develop a diffuse histologic pattern when they recur. Immunohistochemical staining suggests a role of mast cells (CD117) and expression of infiltration makers (CD44) in the transformation of plexiform tumors to the diffuse phenotype.

Eyelid-Cheek Junction Soft-Tissue Perineurioma: Case Report and Controversies

Perineurioma is a rare soft-tissue tumor with characteristic histologic and immunohistochemical features. The diagnosis; however, can be met with certain challenges. A 71-year-old woman presented with an enlarging painless mass in the right lower eyelid-cheek junction. The lesion presented as a raised overhanging trunk-shaped mass. An excisional biopsy and local reconstruction were performed. The overall morphology and immunohistochemical findings were most supportive of a cellular soft-tissue perineurioma, with differential diagnoses including dermatofibroma. To the authors' knowledge, this is the first histopathologically reported case of a superficially occurring soft-tissue perineurioma in the eyelid-cheek junction. The authors discuss the presentation, relevant literature, and controversies associated with this diagnosis.

Differential gene methylation and expression of HOX transcription factor family in orbitofacial neurofibroma

Although most commonly benign, neurofibromas (NFs) can have devastating functional and cosmetic effects in addition to the possibility of malignant transformation. In orbitofacial neurofibromatosis type 1, NFs may cause progressive, disfiguring tumors of the lid, brow, temple, face and orbit. The purpose of this study was to identify biological differences between orbitofacial NFs and those occurring at other anatomic sites. We used Illumina Methylation EPIC BeadChip to study DNA methylation differences between orbitofacial NFs (N = 20) and NFs at other sites (N = 4). Global methylation differences were detected between the two groups and the top differentially methylated genes were part of the HOX (Homebox) family of transcription factors (HOXC8, HOXC4, HOXC6, HOXA6 and HOXD4), which were hypomethylated in orbitofacial NFs compared to the non-orbital NFs. Conversely, LTF (lactoferrin) was relatively hypermethylated in orbitofacial NF compared to non-orbitofacial NF. HOXC8 protein levels were higher in orbitofacial plexiform NFs (p = 0.04). We found no significant differences in the expression of HOXC4, HOXA6, or HOXD4 between the two groups. HOXC8 mRNA levels were also higher in orbitofacial NFs and HOXC8 overexpression in a non-neoplastic human Schwann cell line resulted in increased growth. In summary, we identified gene methylation and expression differences between orbitofacial NF and NFs occurring at other locations. Further investigation may be warranted, given that the HOX family of genes play an important role during development, are dysregulated in a variety of cancers, and may provide novel insights into therapeutic approaches.

Solitary neurofibroma of the orbit with intracerebral extension associated with ocular surface melanocytoma: a case report

Solitary or isolated neurofibroma is uncommonly observed in the orbit. Neurofibromas typically involve peripheral nerves and occasionally the cranial nerves. A 29-year-old man presented with recent onset left eye proptosis and exotropia. Physical examination was positive for hyperpigmented lesions of the ipsilateral ocular surface and hard palate. Imaging revealed an infiltrative orbital mass with extension through superior orbital fissure into the brain. There was also bone defect of greater sphenoid wing. Medial orbitotomy was performed to obtain biopsies of the orbital mass and the pigmented ocular surface lesions. Histopathologic diagnosis of neurofibroma was confirmed for the former and melanocytoma for the latter. His symptoms and examinations remained stable during the follow up. This case is unique due to several features, including extensive intracerebral spread of orbital neurofibroma in a patient without definite diagnosis of neurofibromatosis type 1 and association with ipsilateral ocular surface melanocytoma and palatal pigmented lesions.

ABBREVIATIONS

CT: computed tomography; GFAP: glial fibrillary acid protein; MRI: magnetic resonance imaging; NF-1: neurofibromatosis type 1.

Surgical Management of Granular Cell Tumor of the Orbit: Case Report and Literature Review

Introduction:

Granular Cell Tumors (GCTs) of the orbit are rare-entity soft-tissue tumors, and few reports have been published in the literature. The treatment of the choice is total excision. Early diagnosis prior to surgery is valuable for the distinction of malignant from benign tumor.

Case presentation:

We report a case of a 55-year-old woman with a solitary slow-growing mass in the right orbit with the involvement of the rectus inferior muscle, and present a review of the recent literature. The lesion had a diameter of 1 cm and was noticed 2 years before the examination. Excisional biopsy confirmed the diagnosis of GCT. The tumor was resected through a retroseptal transconjunctival approach. The final histological examination revealed findings characteristic of GCT, including positive reaction for protein S-100, SOX10, and calcitonin and negative reaction for desmin, myogenin, Smooth Muscle Antigen (SMA), Melan-A, and HMB-45. There were no signs of malignancy in this sample. Disturbance of motility was not noted by the patient after surgery.

Conclusion:

GCT should be included in the differential diagnosis of intraorbital lesions, particularly those that involve the orbit muscles. A biopsy is recommended before surgical resection, to exclude malignancy and prevent radical resection.

Primary conjunctival myxoma: case series and review of the literature

AIMS

Myxomas are benign soft tissue tumours resembling primitive mesenchyme. They rarely involve ocular structures, and have been recognized in the conjunctiva, eyelids, cornea, and orbit. The aim of this study was to investigate the clinicopathological features of seven patients with primary conjunctival myxoma seen at Dr Luis Sánchez Bulnes Hospital, an ophthalmological referral centre in Mexico City.

METHODS AND RESULTS

We reviewed the clinical, histochemical and immunohistochemical studies of patients with documented myxoma of the conjunctiva diagnosed in our hospital. Seven conjunctival myxomas were retrieved from 5923 conjunctival biopsies (0.1%). The mean age of patients was 40 years, with a range of 27-51 years. Females were more frequently affected, and none of our patients had systemic disease. The left eye was involved in five cases, and most of the lesions were located in the bulbar conjunctiva. Histopathological examination revealed a benign tumour composed of spindle-shaped and stellate-shaped cells immersed within an abundant mucinous matrix with sparse vessels and reticulin fibres. Immunohistochemistry demonstrated positivity for vimentin and negativity for smooth muscle actin, SOX10 and GLUT1 in myxoma cells of all cases. S100 was found to be positive in four cases, and muscle-specific-actin in three cases.

CONCLUSIONS

Conjunctival myxomas are uncommon tumours. For accurate diagnosis, histopathological examination is mandatory. The treatment of choice is surgical removal, and the prognosis is excellent.

Solitary neurofibroma of eyelid masquerading as chalazion

Neurofibroma, a benign peripheral nerve sheath tumor, usually appears together with café-au-lait spots, iris nodules, and other tumors within the scope of neurofibromatosis von Recklinghausen type 1 tumors. A solitary neurofibroma of the eyelid is relatively rare. In this case report, we present a 39-year-old woman who had a lesion on the eyelid crease, previously treated as a chalazion. Due to persistent wound crusting, the lesion was excised above the tarsus. Pathological examination revealed a solitary neurofibroma. The patient did not have other clinical symptoms of neurofibromatosis, and there was no recurrence of the nodule during the 1-year follow-up.