Classic neurothekeoma (nerve sheath myxoma) and cellular neurothekeoma of the oral mucosa: immunohistochemical profiles

Pediatric cellular neurothekeoma: Seven cases and systematic review of the literature

BACKGROUND/OBJECTIVES

Neurothekeoma is a rare, benign, cutaneous neoplasm consisting of Schwann cells and perineural cells in myxoid stroma. Cellular neurothekeoma (CNT) was previously thought to represent a morphologic variant of neurothekeoma, but recent studies have shown that CNTs are unrelated to neurothekeomas and are more likely of histiocytic lineage.

METHODS

Herein, we describe seven cases of CNT in pediatric patients. A comprehensive search of PubMed was performed, and 71 cases of cellular neurothekeoma in pediatric patients were reviewed.

RESULTS

The clinical differential diagnosis for these lesions included Spitz nevi, keloid, juvenile xanthogranuloma, cutaneous lymphoid hyperplasia, and lymphomatoid papulosis. All cases were treated by excision or excisional biopsy. Histopathologically, all demonstrated multilobular, primarily intradermal neoplasms composed of plump spindled or epithelioid mononuclear cells with abundant eosinophilic pale-staining cytoplasm. Immunophenotypic findings included CD68 and NKI/C3 positivity, and negative staining with cytokeratin, S-100, Melan-A, and SOX-10.

CONCLUSION

Cellular neurothekeoma is distinguished from conventional neurothekeoma by increased cellularity, a lack of myxoid stroma, and a lack of neural expression with immunohistochemical stains. These uncommon neoplasms should be included in the differential diagnosis of dermal nodules in children. Accurate diagnosis of these lesions is essential, as they can be mistaken for malignancy leading to unnecessary treatment.

Oral neural tumors: Clinicopathologic analysis of 157 cases and review of the literature

Background

Oral neural tumors (ONTs) are rare lesions and represent reactive or neoplastic proliferations of nerve sheath cells. The purpose of the present study is to report the clinical, demographic and histopathologic features of 157 ONTs diagnosed in a single Oral Pathology Department and review the pertinent literature.

Material and Methods

157 cases of ONTs diagnosed during a 44-year period were retrospectively collected and the diagnosis was reconfirmed by studying representative haematoxylin and eosin stained tissue sections. The patients’ gender and age, as well as the main clinical features of the lesions, were retrieved from the biopsy submission forms.

Results

The 157 ONTs represented approximately 0.4% of 35,590 biopsies accessioned during the study period. They affected 71 male and 86 female patients with a mean age of 38.4±18.8 years. They mainly appeared as asymptomatic nodules of normal or white colour on the tongue, lip mucosa and hard palate. The most common ONT was granular cell tumour (38.9%) followed by neurofibroma (19.7%), schwannoma (15.9%), traumatic neuroma (15.9%), palisaded encapsulated neuroma (8.3%) and nerve sheath myxoma (1.3%).

Conclusions

This study confirmed the rarity of ONTs. Their clinical characteristics mimic other oral lesions; thus, microscopic examination is the only mean to arrive at a definitive diagnosis.

Key words:Oral neural tumors; oral neural neoplasms; neurofibroma; oral neurofibroma; schwannoma; oral schwannoma; neurilemmoma; oral neurilemmoma; granular cell tumor; oral granular cell tumor; traumatic neuroma; oral traumatic neuroma; palisaded encapsulated neuroma; oral palisaded encapsulated neuroma.

Oral nerve sheath myxoma: a rare and unusual intraoral neoplasm

We present a rare case of intraoral nerve sheath myxoma. Clinically, the neoplasm mimics many other oral mucosal pathosis, underscoring the importance of histopathology in ensuring accurate diagnosis of oral mucosal lesions. Reports of intraoral nerve sheath myxomas are essential to enhance our understanding of this rare intraoral entity.

Multiple Desmoplastic Cellular Neurothekeomas in Child: Report of the First Oral Case and Review of the Literature

Cellular neurothekeomas (CNs) are distinctive benign tumors of uncertain histogenesis, with predilection for the skin of the head and neck region. We describe the first case of multiple desmoplastic CNs (DCNs) affecting the oral cavity in a 9-year-old girl. Histopathologic evaluation showed a proliferation of spindle and epithelioid cells, forming nests and bundles, supported by exuberant fibrous stroma, as well as scattered multinucleated floret-like giant cells. The tumor cells were immunopositive for vimentin, CD63, CD56, whereas AE1/AE3, S100, CD34, α-SMA, GFAP, EMA, CD57 and NSE were negative. Ki-67 was <2%. Multiple DCNs should be considered in the differential diagnosis of oral nodular lesions.

Oral Neurothekeoma of the Right Buccal Mucosa

Oral neurothekeoma or nerve sheath myxoma is a rare benign oral tumour of nerve sheath origin. Historically, this tumour has been subclassified as myxoid (classic), mixed, or the cellular type, depending on the amount of myxoid stroma and cellularity. We present a case of oral neurothekeoma (mixed type) of the buccal mucosa. The tumour was completely excised. No recurrence was detected in the last 3 years after local excision.

A giant neurothekeoma of the left shoulder blade: A case report

Neurothekeoma is a rare myxoma of the peripheral nerve sheath. The current report presents a case of a giant neurothekeoma with a partially-formed capsule, scapula erosion and unclear biological behavior, which originated in the intermuscular space between the left trapezius muscle and scapula. The patient was initially misdiagnosed with a fibromatosis using computed tomography and magnetic resonance image scanning. Diagnosis of the neoplasm was confirmed by pathological and immunohistochemical examination, revealing a neurothekeoma with unclear biological behavior. The patient underwent a wide and complete local resection. Using a comprehensive postoperative follow-up strategy, it was determined that the patient recovered well. The tumor was ~17×16×10 cm in size and was in contact with the scapula. The purpose of the present study was to describe a rare giant neurothekeoma and review the diagnostic techniques utilized to reach a definitive diagnosis. Histopathological and immunohistochemical analyses were recommended for the diagnosis of neurothekeoma. There have been no previous reports regarding neurothekeomas exhibiting malignant transformation. Early and complete surgical resection is considered to be an effective method of treating this type of neurothekeoma.

Mediastinal neurothekeoma: a rare tumor

Neurothekeoma, also known as nerve sheath myxoma, is a benign nerve sheath tumor that usually arises in the cutaneous nerves of the head, neck, or upper extremities. Extracutaneous placement is very rare. Mediastinal neurothekeoma has not previously been reported in the English literature. A 30-year-old woman was admitted to our clinic with back pain. A smooth-edged mass found in her paravertebral region, and a neurogenic tumor was suspected. The tumor was completely excised. Final pathology revealed it to be a mediastinal neurothekeoma.

Myxoid Cellular Neurothekeoma: A New Entity of S100-Negative, CD68-Positive Myxoid Neurothekeoma

Neurothekeoma is a rare cutaneous neoplasm, occurring as a cutaneous papule or nodule on the face, shoulders, and upper extremities. Neurothekeoma has been subclassified as either the myxoid, cellular, or mixed type, depending on the amount of myxoid matrix and on immunohistochemical analysis. We observed a clinical case with conflicting histopathological and immunohistochemical findings. In this case, microscopic examination showed the typical presentation of myxoid neurothekeoma; however, immunohistochemical staining was negative for S100 protein and positive for CD68, which is the characteristic pattern of cellular neurothekeoma. We report a very rare form of myxoid cellular neurothekeoma of the face in a young woman.

Cellular neurothekeoma: analysis of 37 cases emphasizing atypical histologic features

Cellular neurothekeoma is a frequent source of diagnostic difficulty. In order to gain more insight into the range of histologic features of cellular neurothekeoma, we examined all cases from our institution, with a focus on describing atypical histologic features. Cases with sufficient histologic material for evaluation were retrieved. Cases were analyzed for demographics, growth pattern, myxoid stroma, cytologic atypia, mitotic rate, perineural invasion, and other histologic features. The 37 patients (16 M; 21 F) had a mean age of 31.0 years (range: 4-89). Tumors involved the head and neck (n=16), arms (n=11), trunk and shoulders (n=8), and foot (n=2). All cases had at least focal nesting of epithelioid to spindled tumors cells characteristic of cellular neurothekeoma. In many, alternate growth patterns were present and represented the dominant pattern in some. These patterns included fascicular (n=9), sheet-like (n=6), and corded (n=4). Myxoid stroma was present in 14 and was prominent in 5. Cytologic atypia was present in 19 patients, with 3 having severe atypia. Mean mitotic rate was 2.0/mm(2) (range 0-10 per mm(2)). Neurotropism was seen in four cases. Other unusual features included collagen trapping, giant cells, hemorrhage, lymphocytic cuffing, chondroid stroma, and cellular vacuolization. Cellular neurothekeoma has a wider range of features than is commonly recognized. The presence of nests of epithelioid tumor cells with characteristic cytologic features, no matter how focal, is a clue to the diagnosis.

Cellular neurothekeoma of the upper lip in an infant

Cellular neurothekeoma is an uncommon benign skin neoplasm and also a variant of neurothekeoma. Cellular neurothekeomas usually occur in the skin of the upper trunk, head, or neck of children and young adults; however, they rarely occur in infants or involve the lip. A 6-month-old male infant was incidentally found to have a tumor in the upper lip. The tumor was elastic, nontender, and movable, and the overlying mucosa and skin were normal without discoloration. The tumor was excised from the mucosal side of the upper lip, and a pathological examination revealed cellular neurothekeoma. Cellular neurothekeoma in the lip of an infant without overlying skin discoloration might delay the diagnosis and lead to wrong preoperative diagnosis. No similar case has been reported in the literature.

Oral cellular neurothekeoma

Cellular neurothekeoma is known as a cutaneous tumor with uncertain histogenesis. Very little involvement of mucosal membrane has been reported in the literature so far. This is a case report of an intraoral lesion in a 15-years-old girl. Histopathologic evaluation showed a tumor-consists of spindle to epitheloid cells forming micronodules in a concentric whorled shape pattern. Tumor cells were positive for CD63, vimentin, and NKI-C3. Total excision was performed and no recurrence happened after 16-month followup.

Intraoral nerve sheath myxoma: case report and systematic review of the literature

BACKGROUND

Oral nerve sheath myxoma (NSM) is an uncommon benign neoplasm with Schwann-cell origin, which is frequently mistaken for neurothekeoma. We report a case of NSM on the buccal mucosa in a 42-year-old woman. This case is compared with previously reported cases and a systematic review is performed.

METHODS AND RESULTS

We conducted a case report and systematic review of oral cases considered true NSMs. A literature search was performed using PubMed, Lilacs, Scielo, Cochrane, SciVerse Scopus, Web of Science, and Embase electronic database. Twenty-five cases of oral NSM were included in the systematic review.

CONCLUSION

Oral NSM is rare and may represent a diagnostic challenge for pathologists. To confirm the diagnosis of NSM, the evaluation of S-100 protein expression or other neural marker is essential. The use of the terms NSM and neurothekeoma as synonymous or as variants of the same tumor should be avoided, because they are clearly distinct lesions.