Expression of TFE3 in Cellular and Myxoid Type of Neurothekeoma: Four Cases in Young Children and Adolescents.

Introduction: Cellular neurothekeoma is a benign tumor that mainly occurs in young children and adolescents. The aberrant expression of transcription factor E3 (TFE3) has not been reported in cellular neurothekeoma previously. Case report: We report four cellular neurothekeoma with aberrant immunohistochemical expression of TFE3 protein. The fluorescence in situ hybridization (FISH) showed no TFE3 gene rearrangement or amplification. Discussion/Conclusion: TEF3 protein expression may not be related to TFE3 gene translocation in cellular neurothekeoma. TFE3 may be a potential pitfall in diagnosis, for several malignant tumors in children also express TFE3. The aberrant expression of TFE3 may offer insights into cellular neurothekeoma etiology, and associated molecular mechanisms.

Neurothekeoma located in the hallux and axilla: Two case reports.

BACKGROUND: Neurothekeomas (NTKs) are rare benign soft tissue tumours that typically occur in the head, trunk, and upper limbs and are rare in other parts of the body. CASE SUMMARY: Herein, we present two rare cases in which primary NTKs were located in the hallux and axilla. A 47-year-old woman complained of a verrucous bulge on the plantar side of the left hallux. The surface skin of the tumour was abraded due to poor wound healing. A 6-year-old boy complained of a gradually growing subcutaneous mass in the axilla. The tumours of both patients were completely resected, and the diagnosis of NTK was confirmed by histopathology. At the one-year follow-up, both patients had a good prognosis without local recurrence. CONCLUSION: To date, NTKs located in the hallux and axilla have rarely been reported in the literature. We describe NTKs that occurred in unconventional areas and summarize the challenges in their diagnosis and differential diagnosis.

Neurotecoma de pálpebra superior esquerda: raro relato de caso / Neurothekeoma of the left upper eyelid: rare case report

Neurotecomas são neoplasias raras, benignas, de presumida linhagem fibro-histiocítica. Ao exame dermatológico e ao anatomopatológico, apresentam múltiplos diagnósticos diferenciais, o que torna sua identificação desafiadora. Relatamos o caso de paciente do sexo masculino, de 28 anos de idade, que apresentou crescimento de pápula endurecida na pálpebra superior direita, com histopatológico e imuno-histoquímica sugestivos de neurotecoma

Neurothekeomas are rare, benign dermal tumors of presumed fibrohistiocytic lineage. They present multiple differential diagnoses, making their identification challenging at the dermatological and anatomopathological examination. We report the case of a 28-year-old man who presented a hardened papule growth on the left upper eyelid with histopathology and immunohistochemistry suggestive of neurothekeoma.

PRAME expression in cellular neurothekeoma: A study of 11 cases.

BACKGROUND: Preferentially expressed antigen in melanoma (PRAME) has been widely investigated in the skin, mainly in melanocytic tumors, and constitutes an aid in differentiating benign from malignant lesions. Very few studies have been performed on non-melanocytic tumors. MATERIALS: We investigated the immunohistochemical expression of PRAME on a series of 11 neurothekeomas (NTKs), together with 3 cases of nerve sheath myxoma (NSM) and 1 case of plexiform fibrohistiocytic tumor (PFT), in order to evaluate the presence and usefulness of this marker in their differential diagnosis. RESULTS: PRAME was variably expressed in all cases of NTK, with moderate intensity in three cases and faint in the remaining cases; on the contrary, cases of NSM and PFT were negative. CONCLUSIONS: This study expands the entities of cutaneous non-melanocytic tumors expressing PRAME, and confirms that this marker is not restricted to malignant tumors. Expression of PRAME in NTK does not seem to be related to distinctive histopathologic features.

Neurothekeoma: Another differential in the diagnosis of a subungual swelling.

CASE: Lesions, which commonly grow and protrude beneath the distal end of a toe nail and present to the podiatrist or foot and ankle surgeon, include subungual exostosis or enchondroma and a Nora lesion. Neurothekeoma is a benign dermal tumour of the peripheral nerve sheath that usually affects the skin of the head, neck, shoulders and arms. It occurs less commonly in the lower limbs and has only been reported twice in a subungual location. A case of subungual neurothekeoma that recurred twice due to inadequate margins of resection is presented. CONCLUSION: Although rare, neurothekeoma should be included in the differential diagnosis of a subungual lesion. Histopathological diagnosis is reached by differential immunostaining. Adequate clear margins of resection are recommended to prevent recurrence.

Neurothekeoma in the Axilla Causing Persistent Shoulder Pain: Case Report.

Neurothekeomas, also known as neural sheath myxomas, are rare benign tumors of the neural sheath affecting most commonly the head, arms and shoulder of women in their 2 nd and 3 rd decades of life. Due to the low prevalence and undefined clinical picture, they are hardly considered in the initial differential diagnosis of skin tumors. We report the case of a 24 year-old woman who was seen in 2016 reporting > 1 year of moderate pain and limited mobility of her left shoulder. Clinical evaluation revealed restricted mobility of the affected shoulder and nuclear magnetic resonance imaging showed a T2-weighted contrast-enhanced multilobular mass in the quadrilateral area apparently invading the adjacent humeral cortical region. Histopathology of a needle sample material revealed loose fibroconnective tissue with no signs of invasion, mitosis or atypical figures. Successful surgical excision was performed and the diagnosis of neurothekeoma was confirmed after detailed histopathology, including immunohistochemistry. The patient was asymptomatic at 18 months of follow-up, with full recovery of shoulder movement and no signs of relapse.

Neurothekeoma in the Axilla Causing Persistent Shoulder Pain: Case Report / Neurotecoma na axila causando dor persistente no ombro: Relato de caso

Abstract Neurothekeomas, also known as neural sheath myxomas, are rare benign tumors of the neural sheath affecting most commonly the head, arms and shoulder of women in their 2nd and 3rd decades of life. Due to the low prevalence and undefined clinical picture, they are hardly considered in the initial differential diagnosis of skin tumors. We report the case of a 24 year-old woman who was seen in 2016 reporting > 1 year of moderate pain and limited mobility of her left shoulder. Clinical evaluation revealed restricted mobility of the affected shoulder and nuclear magnetic resonance imaging showed a T2-weighted contrast-enhanced multilobular mass in the quadrilateral area apparently invading the adjacent humeral cortical region. Histopathology of a needle sample material revealed loose fibroconnective tissue with no signs of invasion, mitosis or atypical figures. Successful surgical excision was performed and the diagnosis of neurothekeoma was confirmed after detailed histopathology, including immunohistochemistry. The patient was asymptomatic at 18 months of follow-up, with full recovery of shoulder movement and no signs of relapse.

Resumo Neurotecomas, também conhecidos como mixomas da bainha neural, são tumores benignos raros da bainha neural afetando mais comumente a cabeça, braços e ombros de mulheres entre 20 e 40 anos de idade. Devido à baixa prevalência e quadro clínico mal definido, essas lesões são raramente consideradas no diagnóstico diferencial de tumores cutâneos. Relatamos o caso de uma mulher de 24 anos de idade que procurou atendimento em 2016 relatando dor moderada por mais de um ano e limitação dos movimentos do ombro esquerdo. Ao exame, foi constatada restrição da mobilidade dessa articulação e uma ressonância magnética revelou imagem multilobular com aumento de sinal em T2 na região quadrilateral, aparentando invasão da região cortical do úmero subjacente. A histopatologia de uma biópsia incisional mostrou lesão composta por tecido conjuntivo frouxo, sem sinais de invasão, figuras de mitose ou atipias. Foi realizada excisão completa da lesão e o diagnóstico de neurotecoma foi confirmado após análise histopatológica que incluiu painel imunohistoquímico. À revisão de 18 meses, a paciente estava assintomática com recuperação completa do movimento e sem evidência de recidiva da lesão.

Nerve Sheath Myxoma: A rare tumor, a case report and literature review.

INTRODUCTION: Nerve Sheath Myxoma is a rare benign nerve sheath tumor, commonly seen in young adults. Patients usually present with a small nodule commonly affecting upper and lower limbs. Nerve Sheath Myxoma has not been reported in children below the age of 1 year. CASE PRESENTATION AND METHODS: We present the first reported case of Nerve Sheath Myxoma (NSM) in the hand in a 4-month old child in line with the SCARE 2018 criteria. DISCUSSION: NSM is difficult to diagnose using standard imaging technique; Magnetic Resonance Imaging (MRI) and Ultrasonography (USS) cannot differentiate it from vascular anomalies. CONCLUSION: Soft tissue tumors in the hand of pediatric population are difficult to diagnose. Formal excision of the tumor by a specialized pediatric hand surgeon and histopathological analysis were the only avenue to correctly diagnose the NSM.

Intraosseous Neurothekeoma of the Hand in a 16-year-old Boy.

Soft-tissue tumors are rare in the pediatric population. First described in 1969 as myxoma of the nerve sheath, the neurothekeoma is a benign tumor lesion with presumable origin in the nerve sheath. It occurs mainly in female children and presents as a mass of slow, subcutaneous growth, asymptomatic and without alteration of the local pigmentation. It is predominantly located in the head, neck, and extremities of the upper limbs. This report presents the case of a 16-year-old male with a tumor mass originating from the nerve sheath in the 4 th left metacarpal, intraosseous, and relapsed after previous surgical resection 2 years before this observation. A marginal resection of the tumor mass was performed on the distal region of the fourth metacarpal, followed by curettage of the proximal phalanx and filling with structural autologous bone graft. The patient maintained a favorable postoperative clinical evolution, without local pain or range of motion limitation in his fingers. Radiologically, a progressive trabecular filling of the proximal phalanx of the fourth metacarpal was observed. At 17 months of follow-up, the patient is asymptomatic and shows no signs of relapse. The description of this case serves to increase the familiarity with this rare pathology, and aid its diagnosis and treatment.

Intraosseous Neurothekeoma of the Hand in a 16-year-old Boy / Neurotequeoma intraósseo da mão de um jovem de 16 anos

Abstract Soft-tissue tumors are rare in the pediatric population. First described in 1969 as myxoma of the nerve sheath, the neurothekeoma is a benign tumor lesion with presumable origin in the nerve sheath. It occurs mainly in female children and presents as a mass of slow, subcutaneous growth, asymptomatic and without alteration of the local pigmentation. It is predominantly located in the head, neck, and extremities of the upper limbs. This report presents the case of a 16-year-old male with a tumor mass originating from the nerve sheath in the 4th left metacarpal, intraosseous, and relapsed after previous surgical resection 2 years before this observation. A marginal resection of the tumor mass was performed on the distal region of the fourth metacarpal, followed by curettage of the proximal phalanx and filling with structural autologous bone graft. The patient maintained a favorable postoperative clinical evolution, without local pain or range of motion limitation in his fingers. Radiologically, a progressive trabecular filling of the proximal phalanx of the fourth metacarpal was observed. At 17 months of follow-up, the patient is asymptomatic and shows no signs of relapse. The description of this case serves to increase the familiarity with this rare pathology, and aid its diagnosis and treatment.

Resumo Os tumores dos tecidos moles são raros em idade pediátrica. Descrito pela primeira vez 1969 como um mixoma da bainha nervosa, o neurotequeoma é uma lesão tumoral benigna com presumível origem na bainha nervosa. Ocorre maioritariamente em crianças do sexo feminino e apresenta-se como uma massa de crescimento lento, subcutânea, assintomática e sem alteração da pigmentação local. Localiza-se predominantemente na cabeça, no pescoço, e nas extremidades dos membros superiores. Os autores apresentam um caso clínico de um jovem de 16 anos do sexo masculino com massa tumoral com origem na bainha nervosa no 4º metacarpo esquerdo, intraóssea e recidivada após ressecção cirúrgica 2 anos antes do estudo. Foi feita ressecção marginal da massa tumoral localizada sobre a região distal do quarto metacarpo e curetagem da falange proximal e preenchimento com enxerto ósseo autólogo corticoesponjoso. O paciente apresentou uma evolução clínica pós-operatória favorável, sem queixas álgicas e sem limitações da mobilidade dos dedos da mão. Radiologicamente, foi observado preenchimento trabecular progressivo da falange proximal do quarto metacarpo. Aos 17 meses de seguimento, o paciente se encontra assintomático e não apresenta quaisquer sinais de recidiva. Com a descrição deste caso, os autores pretendem aumentar a familiaridade com essa rara patologia, seu diagnóstico e tratamento.

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.

Co-expression of CD34 and h-caldesmon in a benign meningioma-like dermal neoplasm, a case report.

Meningioma-like dermal tumor with diffuse coexpression of CD34 and hcaldesmon is rarely reported. Herein, we report a case of a 58-years-old woman who complained of a solitary dome-shaped papule on the left hand. An ellipse of skin measuring 1 x 0.5 x 0.5 cm was excised and sent for histopathological evaluation. Upon sectioning, the specimen showed a whitish firm dermal nodule measuring 3 mm in its greatest dimension. Microscopic examination revealed a well-circumscribed barely encapsulated dermal lesion showing compact round whorled sheets formed of round to ovoid uniform cells with abundant pink cytoplasm. Occasional intranuclear vacuoles were seen. A minor capillary-sized vascular component was seen in the background. Immunohistochemical (IHC) study revealed a diffuse positivity of tumor cells to CD34 and h-caldesmon along with faint reaction to Smooth Muscle Actin (SMA) and ER. However, Desmin, S100, HMB45, EMA, Pan Cytokeratin, and Chromogranin were all negative. Ki67 was very low (1%). The main differential diagnoses of the current lesion are meningioma and glomus family tumors. While the current lesion is morphologically reminiscent of cutaneous meningioma; neither the location nor the IHC stains support that diagnosis. The glomus family is highly suggestive. However, the location, the compact nature of the proliferation, and the positivity of CD34, all are unusual in such entities.

Atypical cellular neurothekeoma (ACN) of the elderly: case report and brief review of the literature.

Atypical cellular neurothekeoma (ACN) is an aggressive and rare variant of cellular neurothekeoma. Only few cases have been reported in the literature and the biological behavior seems to be uncertain. We describe the case of an ACN presenting on the scalp of an elderly man, emphasizing the cytologic features of malignancy. In addition, we provide a brief overview of the literature and discuss the differential diagnosis with other entities, and the possible diagnostic pitfalls.

A Case Report of a Nerve Sheath Myxoma of the Lower Eyelid in a Young Male.

Myxomas are rare, benign tumors of uncertain etiology. Based on the published data, there have been few reported cases of eyelid nerve sheath myxomas and two cases of orbital myxomas. Eyelid nerve sheath myxomas have a similar presentation to neurothekeoma of the myxoid variety, and historically these two diagnoses have been considered interchangeable. At present, the proper diagnosis can be found through protein immunoreactivity with histological staining. Currently in published literature, there has not been documentation of a family history with eyelid growth in patients diagnosed with nerve sheath myxomas. In this case report, we present a 19-year-old male with a potential third recurrence of nerve sheath myxoma who reports a family history of similar eyelid lesions.

Sleeve-Shaped Neurothekeoma of the Ulnar Nerve: A Unique Case of a Still Unclear Pathological Entity.

Background: Neurothekeomas are slow-growing, well-circumscribed benign neoplasms. They usually involve cutaneous or subcutaneous tissues. Although originally described as myxomas deriving from nerve sheath cells, their exact histological classification is still uncertain. Peripheral nerve localization is rarely reported. Here, we describe a unique case of sleeve-shaped neurothekeoma of the ulnar nerve, which was incidentally discovered during a cubital tunnel release surgery. Methods: A 57-year-old man was admitted at our institution with clinical, ultrasonographic, and electromyographic findings highly suggestive of cubital tunnel syndrome. During ulnar nerve decompression surgery, however, no bony or ligament compression was noticed, but a segment of the nerve wrapped by a thick sleeve-shaped tissue, which had no clear-cut cleavage plane from the nerve. Given this unexpected finding, the en bloc excision of the lesion was avoided. A nerve decompression with biopsy of the swelling portion of the lesion was performed instead. Results: Histological examination described abundant myxoid stroma, with epithelioid and ring-shaped cells arranged in cords, negative to S100 protein at immunohistochemical analysis. This pattern was suggestive of neurothekeoma. The patient showed improvement in hypermyotrophy and intrinsic weakness of the hand. Conclusions: To the best of our knowledge, this is the first report of a sleeve-shaped neurothekeoma of the ulnar nerve. The exact pathological characterization of such rare entities remains uncertain. In case of peripheral nerve localization, and when a clear cleavage plane is absent, the correct management of these lesions should be that of simple nerve decompression followed by biopsy.

Neurothekeoma: Report of two cases in children and review of the literature.

Neurothekeomas, or simply nerve sheath myxomas, are rare benign skin neoplasms. They are believed to derive from peripheral nerve sheath transformation and are typically more prevalent in females. They tend to be found mainly on the upper limbs as well as head and neck locations. In this report, we detail two children with neurothekeomas, describe the fundamental clinical manifestations, and review the current literature.