Cellular neurothekeoma of the oral mucosa

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.

Neurothekeoma

OBJECTIVES:

The purpose of this study was to investigate and share the experiences at The University of Texas M. D. Anderson Cancer Center in diagnosing, treating, and following patients with neurothekeoma. We report 13 cases.

STUDY DESIGN

Case series. The clinical, surgical, and pathology records of the 7 patients with neurothekeoma treated at M. D. Anderson Cancer Center were retrospectively reviewed. In addition, the pathology records of 6 patients reviewed by the Department of Pathology for diagnosis only were retrospectively reviewed.

RESULTS:

Nine patients were women. Their mean age was 30 years (median, 24 years). Six of the lesions were on the head or neck, 4 were on extremities, and 2 were on the trunk, and the location of 1 was not recorded. Two lesions had been previously diagnosed, histologically, as leiomyosarcomas, 1 as a malignant nodular hidradenoma, and 1 as a clear cell hidradenoma. All the lesions had the characteristic nested pattern of growth, with various degrees of myxoid background. Mitotic figures and marked cellular pleomorphism were not common. Six cases were treated with wide local excision. A lesion of the nasal ala was excised by using Möhs micrographic surgery. Most cases were limited to the dermis, but 2 lesions infiltrated subcutaneous tissue and skeletal muscle. All patients were without evidence of disease at 8 months median follow-up range (0 to 35 months).

CONCLUSION:

Neurothekeoma is a benign neoplasm occurring usually in women and commonly in the head and neck. Because it may be locally invasive, treatment with wide local excision using frozen section control of margins is recommended. Care must be taken in the pathologic diagnosis of cutaneous neoplasms, and neurothekeoma should be considered in the differential diagnosis for spindle cell lesions.

SIGNIFICANCE

Neurothekeoma is commonly misdiagnosed, pathologically and clinically, and it can be treated successfully with surgical excision. EBM rating: C.

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.

A rare case of atypical cellular neurothekeoma in a 68-year-old woman

Cellular neurothekeoma is a benign dermal lesion of uncertain differentiation. The atypical variant of cellular neurothekeoma, characterized by features such as large size, deep penetration, diffusely infiltrative borders, vascular invasion, high mitotic rate and marked cytologic pleomorphism, has been very rarely reported in the literature. We present the clinical, histopathological and immunohistochemical profile of a new case of atypical cellular neurothekeoma in a 68-year-old female patient who was diagnosed with ductal breast carcinoma in situ before. An erythematous painless papule arose in her right breast, and tentative clinical diagnosis was orientated toward skin metastasis of breast cancer or fibroma. Upon histological examination, the lesion showed the histological and immunohistochemical features of atypical variant of cellular neurothekeoma with high mitotic rate, marked cellular pleomorphism and penetration into subcutaneous fat. A further unusual feature in our patient was her age, because she is the oldest patient reported in the literature with diagnosis of atypical cellular neurothekeoma so far. Prognosis remains uncertain because only few cases of atypical cellular neurothekeoma have been reported in the literature, with a very limited follow-up time. Our report contributes to a better characterization of the clinical and morphologic features of atypical cellular neurothekeoma.

Nerve Sheath Myxoma of the Gingiva: Report of a Rare Case and Review of the Literature

BACKGROUND

Nerve sheath myxoma (NSM) is an extremely rare benign neoplasm in the oral cavity. This paper describes the first case, to our knowledge, of NSM in the gingival mucosa of an 84-year-old female patient.

METHODS

Intraoral examination revealed a painless and well-defined nodule in the lingual gingival mucosa of the right mandibular lateral incisor, which measured approximately 1.0 cm in diameter. The lesion was fully excised under local anesthesia, without intercurrences. Hematoxylin and eosin staining was performed in 5-microm sections for histopathologic analysis. Immunohistochemical reactions against vimentin and S-100 protein were carried out in 3-microm histologic sections in accordance with manufacturers' instructions.

RESULTS

The patient's medical history and an extraoral exam did not reveal other abnormalities. The patient wore a removable partial denture in the affected area. A trauma-induced gingival hyperplasia was the main diagnostic hypothesis. Microscopically, the lesion was composed of an abundant myxoid matrix and stellated and spindle-shaped cells arranged in lobules separated by fine fibrous septa. The cells presented strong positivity for vimentin and S-100 protein. According to the histopathologic and immunohistochemical features, the diagnosis of NSM was established. After 9 months of treatment, no signs or symptoms of recurrences have been observed.

CONCLUSION

Although NSM is an extremely rare oral tumor, it should be considered in the clinical differential diagnosis of gingival nodules.

Cellular neurothekeoma with a plexiform morphology: a case report with a discussion of the plexiform lesions of the skin

Neurothekeoma is a rare benign dermal lesion that is commonly seen in children and teenagers. Despite its name, the true nature of this lesion is uncertain and controversial, particularly after the emergence of the cellular (spindle/epithelioid) variant. We describe the histological and immunohistochemical findings of a right thigh skin lesion in an 11-year-old girl. It consists of a dermal ill-defined plexiform mass composed of nests and fascicles of spindle cells with pale eosinophilic cytoplasm that lie within a sclerotic stroma. The immunohistochemistry shows diffuse reactivity to CD68, matrix metalloproteinase-II, CD10 and PGP9.5 with focal reactivity to CD57 and CD34. The lesion is negative for S100, factor XIIIa, smooth muscle markers and melanocytic markers. The features are compatible with a cellular variant of neurothekeoma with plexiform pattern that also exhibits an unusual pattern of fibrohistiocytic phenotype. Although such a lesion is benign, it has a wide but important differential diagnoses that are reviewed briefly together with a brief discussion about the origin of this rare entity.