Nasal Chondromesenchymal Hamartoma with Skull Base and Orbital Involvement: Case Presentation.

Nasal chondromesenchymal hamartoma (NCMH) is a rare benign tumor of the sinonasal tract in children with possible orbit and skull base involvement. We present the 57th published observation of this kind of tumor. A 25-month-old female patient presented with recurrent mass lesion of the sinonasal tract. According to her history, she had feeding difficulties and nasal obstruction since birth. She underwent partial resection at eight months of age via transfacial approach in the local hospital. Due to progression of tumor remnants, a second surgery was performed using an endoscopic endonasal approach resulting in subtotal resection. At 12 months of follow-up, a good postoperative result was observed with no signs of tumor progression despite incomplete resection. Histological and immunohistochemical examination of the biopsy specimens is presented. Comparison of specimens obtained from each of the two surgeries showed a difference in histological patterns. Endoscopic endonasal approach is the mainstay of surgical management. In case of incomplete resection, careful follow-up MRI studies should be recommended.

Comparative integrated molecular analysis of intraocular medulloepitheliomas and central nervous system embryonal tumors with multilayered rosettes confirms that they are distinct nosologic entities.

Intraocular medulloepithelioma (IO MEPL) is an uncommon embryonal neuroepithelial neoplasm of the eye. These ocular neoplasms have been compared with intracranial medulloepitheliomas or other histologic variants of CNS embryonal tumor with multilayered rosettes (CNS ETMR) due to their morphological mimicry. We performed comprehensive molecular analysis to explore the histogenetic and biologic relationships between 22 IO MEPL and 68 CNS ETMR. Routinely prepared paraffin-embedded samples were assessed for genome-wide methylation profiles using the Illumina Methylation 450k BeadChip array. We identified strong cytogenetic and epigenetic differences between ocular neoplasms and CNS ETMR. None of the IO MEPL cases displayed the ETMR-specific amplification of the C19MC locus. Instead, cytogenetic analysis of the IO MEPL showed numerous copy number aberrations which involved either whole chromosomes or chromosomal arms; recurrent aberrations in these tumors affected chromosomes 1p, 4, 8 and 16p. DNA methylation patterns were also strikingly different between these two tumor entities, suggesting that they do not share common origins and biological behaviors. Comparative cluster analysis of 198 pediatric CNS tumors and 22 IO MEPL revealed a clear demarcation of the CNS ETMR and IO MEPL profiles from other CNS entities. In conclusion, although IO MEPL shares some histopathological features with CNS ETMR, they manifest striking molecular diversity at the cytogenetic and epigenetic levels. Consequently they deserve a separate nosologic designation in future tumor classifications, where CNS MEPL could be designated as a histological variant of CNS ETMR.