Myogenic and melanotic differentiated medulloblastoma: case report

Abstract

Medulloblastoma is the most common malignant tumor of childhood and usually arises from the cerebellar vermis. Several histological types of medulloblastoma have been described. Myogenic and melanotic differentiated medulloblastoma are seldom seen. We present a case diagnosed as myogenic medulloblastoma with focal areas of melanotic differentiation. A 4-year-old boy was admitted due to headache, nausea and vomiting for a month. MRI revealed a heterogeneous enhanced posterior fossa tumor rising from the fourth ventricle. He was operated and pathological examination of the specimen revealed myogenic medulloblastoma with myogenic and melanotic differentiation. According to our knowledge there are six cases reported in the literature so far. Oncogenic factors in medulloblastoma development are controversial. Presence of multiple differentiation patterns supports a pluripotent origin for these tumors.

Melanotic Neuroectodermal Tumor of Infancy (MNTI) and Pineal Anlage Tumor (PAT) Harbor A Medulloblastoma Signature by DNA Methylation Profiling

“…Interestingly, MNTI overlaps with the rare pineal anlage tumor (PAT), which is regarded as a variant of pineoblastoma [10]. It also shows morphologic overlap with melanotic medulloblastoma, which was proposed as a possible variant of MNTI [11]. However, this theory is debatable given the usual aggressive course of melanotic medulloblastomas in contrast to the generally benign behavior of MNTI [12].…”

WNT‐activated medulloblastoma with melanotic and myogenic differentiation: Report of a rare case

“…About 12 cases of MB with melanotic differentiation and 50 cases of MB with rhabdomyoblastic differentiation have been reported. MBs with melanotic and myogenic differentiation are still rarer, with only 10 cases reported in the English literature to date (Table ) . These tumors occurred in young children (mean age: 4 years), showed a male predominance, and the majority were associated with the classic variant, and only two of them were seen in large cell/ anaplastic variants .…”

“…MBs with melanotic and myogenic differentiation are still rarer, with only 10 cases reported in the English literature to date (Table 1). [1][2][3][4][5][6][7][10][11][12] These tumors occurred in young children (mean age: 4 years), showed a male predominance, and the majority were associated with the classic variant, and only two of them were seen in large cell/ anaplastic variants. 11,12 While a single case of melanocytic differentiation has been reported in a desmoplastic/ nodular MB, 13 none of the reported MBs with melanotic and myogenic differentiation showed desmoplastic/ nodular histology.…”

“…MB with melanotic and myogenic differentiation, previously documented as pigmented MB with myogenic differentiation and pigmented / melanotic medullomyoblastoma, is an extremely rare variant of MB showing melanocytic as well as rhabdomyoblastic differentiation. It is not considered as a distinct entity, but as a pattern of differentiation seen in association with any of the four major histological variants of MB, most commonly with the classic subtype . Currently, the treatment of this tumor is the same as that of MB and the prognosis depends on the histological variant it is associated with.…”

“…It is not considered as a distinct entity, but as a pattern of differentiation seen in association with any of the four major histological variants of MB, most commonly with the classic subtype. [1][2][3][4][5][6][7] Currently, the treatment of this tumor is the same as that of MB and the prognosis depends on the histological variant it is associated with. It is not known whether multi-lineage differentiation in MB has any distinct clinical or molecular genetic features, presumably due to rarity of this entity, and its molecular genetics with respect to the four recently described molecular MB subgroups remain to be identified.…”