Melanotic neuroectodermal tumor of infancy of the femur

Calvarial Melanotic Neuroectodermal Tumor of Infancy with Rhabdomyosarcomatous differentiation-A Rare Case

BACKGROUND

Malignant neuroectodermal tumor of infancy is a rare neural crest cell-derived neoplasm of infants. Histologically, melanotic neuroectodermal tumor of infancy usually consists of 2 types of cells: neuroblast-like and melanocyte-like cells. Here we present a rare case of melanotic neuroectodermal tumor of infancy containing a third type of cell population, that is, rhabdomyoblasts in addition to the above two.

CASE DESCRIPTION

We report a case of a 10-month-old female child who was brought to us with complaints of swelling over the right forehead for the last 9 months, which started increasing in size rapidly 3 months before presenting to us. Noncontrast computed tomography scan showed a large well-defined extra-axial lesion in the right frontotemporal region. The child underwent an open biopsy under general anesthesia. Histopathological sections showed a malignant small round cell tumor consisting of hyperchromatic cells lying in sheets and lobules separated by fibrous septae. The patient underwent 7 cycles of neoadjuvant chemotherapy over a period of 2 months. The patient underwent right frontotemporal craniotomy and gross total excision of the lesion as a definitive surgery. Postoperatively, the patient was stable, and there was no new deficit. Histopathology revealed neuroblast-like and melanocyte-like cells with rhabdomyosarcomatous differentiation. The patient received chemotherapy in the postoperative period. The patient had recurrence of the tumor and died 8 months after the surgery.

CONCLUSIONS

Calvarial malignant neuroectodermal tumor of infancy with rhabdomyosarcomatous differentiation is a rare entity with no cases being reported before. Neoadjuvant chemotherapy with surgical excision can be a promising modality of treatment.

Melanotic neuroectodermal tumour of infancy presenting as a lytic lesion in femur: a rare tumour at a rare site with an unusual behaviour

Melanotic neuroectodermal tumour of infancy (MNTI) is an uncommon tumour, predominantly occurring in head and neck, mostly maxilla, but also in skull and mandible. Although a benign lesion, it is known to recur in 15%-27% of cases, and rarely, may undergo malignant transformation. We present a case of a 5-month-old female patient, who presented with a gradually progressive swelling in the right thigh. On imaging, an osteolytic lesion was seen, involving the metadiaphysis of shaft of right femur. A biopsy was performed, on which diagnosis of MNTI was made. MNTI is rarely seen in extremities. To the best of our knowledge, only six cases have been reported in femur, the present case being the seventh. The tumour showed spontaneous regression on follow-up in our patient, which has rarely been described. A knowledge of characteristic morphology and immunohistochemistry is the key to differentiate it from other tumours.

Spontaneous Regression of Diffuse Periosteal Melanotic Neuroectodermal Tumor of Infancy in the Tibia, With 13-Year Follow-up

Melanotic neuroectodermal tumor of infancy (MNTI) is a rare entity primarily affecting the craniofacial bones during the first year of life, with only 5 reported cases involving peripheral long bones. We herein present a case of MNTI in the tibia of an infant, with a somewhat atypical presentation, and a noteworthy clinical course characterized by progressive spontaneous resolution without therapy, thus sparing the child the trauma of amputation. There is no evidence of active residual or recurrent disease with 13-year follow-up. To the best of our knowledge, essentially all reported cases of MNTI have received empirical treatment, some at the price of mutilating surgery or fatal chemotherapy. We propose that the necessity of aggressive treatment be evaluated on a case-by-case basis, especially in patients with diffuse periosteal involvement, as in this patient. A trial of watchful waiting can be considered when treatment would involve substantial morbidity or risk of complications.

Melanotic Neuroectodermal Tumor of Infancy

Context.—

Melanotic neuroectodermal tumor of infancy, albeit rare and generally regarded as benign, is an important tumor to recognize because of its rapid growth, potential for local recurrence, and small round blue cell morphology, which can lead to misdiagnosis of a malignant neoplasm.

Objective.—

To review its clinical presentation and immunomorphologic findings, and discuss common entities in the differential diagnosis.

Data Sources.—

The study involved PubMed searches, including multiple review articles, case studies, retrospective studies, selected book chapters, and University of Michigan cases.

Conclusions.—

Melanotic neuroectodermal tumor of infancy most commonly occurs in the bones of the head and neck region during the first year of life, but it can also present in other locations, including the central nervous system, testes, ovaries, and subcutaneous soft tissues. Histologically, it is composed of a biphasic population of cells, consisting of epithelioid melanin-producing cells and primitive neurogenic cells in a fibrocollagenous stroma. These microscopic findings, especially in small biopsies, can lead to a broad differential diagnosis that includes malignant small round blue cell tumors and malignant melanoma. Melanotic neuroectodermal tumor of infancy commonly has an infiltrative growth pattern, and anatomic constraints often lead to incomplete resection and local recurrence, requiring multiple surgical operations. Because melanotic neuroectodermal tumor of infancy can mimic a more aggressive and aggressively treated malignancy, recognition of this rare tumor is very crucial for pathologists.

A germline mutation of CDKN2A and a novel RPLP1-C19MC fusion detected in a rare melanotic neuroectodermal tumor of infancy: a case report

Background

Melanotic neuroectodermal tumor of infancy (MNTI) is exceptionally rare and occurs predominantly in the head and neck (92.8 % cases). The patient reported here is only the eighth case of MNTI presenting in an extremity, and the first reported in the fibula.

Case presentation

A 2-month-old female presented with a mass arising in the fibula. Exhaustive genomic, transcriptomic, epigenetic and pathological characterization was performed on the excised primary tumor and a derived cell line. Whole-exome analysis of genomic DNA from both the tumor and blood indicated no somatic, non-synonymous coding mutations within the tumor, but a heterozygous, unique germline, loss of function mutation in CDKN2A (p16^INK4A, D74A). SNP-array CGH on DNA samples revealed the tumor to be euploid, with no detectable gene copy number variants. Multiple chromosomal translocations were identified by RNA-Seq, and fusion genes included RPLP1-C19MC, potentially deregulating the C19MC cluster, an imprinted locus containing microRNA genes reactivated by gene fusion in embryonal tumors with multilayered rosettes. Since the presumed cell of origin of MNTI is from the neural crest, we also compared gene expression with a dataset from human neural crest cells and identified 185 genes with significantly different expression. Consistent with the melanotic phenotype of the tumor, elevated expression of tyrosinase was observed. Other highly expressed genes encoded muscle proteins and modulators of the extracellular matrix. A derived MNTI cell line was sensitive to inhibitors of lysine demethylase, but not to compounds targeting other epigenetic regulators.

Conclusions

In the absence of somatic copy number variations or mutations, the fully transformed phenotype of the MNTI may have arisen in infancy because of the combined effects of a germline CDKN2A mutation, tumor promoting somatic fusion genes and epigenetic deregulation. Very little is known about the etiology of MNTI and this report advances knowledge of these rare tumors by providing the first comprehensive genomic, transcriptomic and epigenetic characterization of a case.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2669-3) contains supplementary material, which is available to authorized users.

Melanotic neuroectodermal tumor of infancy in thigh of an infant--a rare case report with diagnostic implications

Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon tumor of neural crest origin, almost invariably identified in the head and neck region. It is a relatively benign tumor but can recur and rarely metastasize. Herein, a rare case of MNTI in the thigh of an infant is documented. Radiographic imaging showed a sclerotic and lytic lesion in the metadiaphyseal region of the right femur with a soft tissue component. The clinicoradiological impression was of a malignant round cell tumor and osteomyelitis. The patient's urinary vanil mandelic acid (VMA) level was elevated. FNAC smears revealed a tumor with round to polygonal cells, focally containing black melanin pigment. Biopsy and tumor excision revealed a tumor with cells in cords and nests embedded in a fibrocollagenous stroma and showed bone and soft tissue infiltration. On immunohistochemistry, tumor cells displayed immunoreactivity to vimentin, cytokeratin (CK), CK7, CK19, and MIC2, and focal reactivity for synaptophysin and HMB45. Diagnosis of an MNTI was made. The patient underwent induction chemotherapy with extracorporeal radiotherapy, followed by a soft tissue excision that revealed residual tumor. Surgically, free marrow margins were accomplished, and the patient is currently being followed-up. To the best of our knowledge this case is the fifth documented case in the English literature of MNTI in the thigh. The diagnostic and therapeutic implications are discussed.

Melanotic neuroectodermal tumour of infancy: report of two cases and review of the literature

Melanotic neuroectodermal tumour of infancy (MNTI) is an uncommon tumour affecting predominantly the craniofacial bones of the newborn infants. The neural crest origin of the tumour has been confirmed. MNTI is generally accepted as a benign tumour despite of its rapid and locally infiltrative growth. Recurrence rate varies between 10% and 60%, and malignant behaviour has been reported in 6.5% of MNTIs. Systematic review of the literature revealed 445 MNTIs published between 1918 and 2010. We present additional two cases of MNTI from our Department, typical in all terms, which equals a total number of 447 reported cases. One of our cases revealed histological features consistent with malignant behaviour, but at present, 18 months after the surgical excision, there is no evidence of recurrence. Biological behaviour of MNTI cannot be predicted by gross or histologic characteristics, thus early diagnosis and careful follow-up after the complete surgical excision is required.

Melanotic progonoma of the skull in infancy

INTRODUCTION

Melanotic progonoma or melanotic neuroectodermal tumor is a rare tumor in infancy. This lesion has to be considered in the differential diagnosis of benign or malignant lesions of calvarium.

CASE REPORT

The authors present a case of a 4-month-old infant with left retroauricular mass. The patient had a subcutaneous mass that is fixed to the underlying skull. CT and MRI scans showed left occipitotemporal expansile mass. The tumor was removed by surgery. A tumor, brownish-black in color, was diagnosed as melanotic progonoma. The patient remained symptom-free for the last 2 years after complete surgery.

DISCUSSION

Extracranial subcutaneous masses involving the skull are uncommon in infants. Benign or malignant lesions may occur as lumps on calvarium. Physical examination and some laboratory findings are helpful in the assessment of patient. Benign or malignant lesions can be differentiated by craniography, CT, or MRI scans, but exact diagnosis of melanotic progonoma is made by histopathology and immunostaining, as was in the presented case. Cranial vault progonomas have a better outcome by complete surgery. The tumors usually do not recur in long-term period.

Melanotic neuroectodermal tumor of infancy in the femur: a case report and review of the literature

Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon neoplasm that most often affects the maxilla in the first year of life. MNTI occurring in the long bones is extremely rare, with only 2 cases reported in the medical literature. Here we report a case of MNTI in the right femur of a 5-month-old infant who underwent neoadjuvant chemotherapy followed by limb-salvage surgery.