Unusual paediatric spinal myxopapillary ependymomas: Unique molecular entities or pathological variations on a theme?

Pediatric CNS tumors and 2021 WHO classification: what do oncologists need from pathologists?

The fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS), published in 2021, established new approaches to both CNS tumor nomenclature and grading, emphasizing the importance of integrated diagnoses and layered reports. This edition increased the role of molecular diagnostics in CNS tumor classification while still relying on other established approaches such as histology and immunohistochemistry. Moreover, it introduced new tumor types and subtypes based on novel diagnostic technologies such as DNA methylome profiling. Over the past decade, molecular techniques identified numerous key genetic alterations in CSN tumors, with important implications regarding the understanding of pathogenesis but also for prognosis and the development and application of effective molecularly targeted therapies. This review summarizes the major changes in the 2021 fifth edition classification of pediatric CNS tumors, highlighting for each entity the molecular alterations and other information that are relevant for diagnostic, prognostic, or therapeutic purposes and that patients' and oncologists' need from a pathology report.

Pediatric Extraspinal Sacrococcygeal Ependymoma: Report of Two Cases and Literature Review

Primary central nervous system (CNS) tumors represent the most common solid tumors in childhood. Ependymomas arise from ependymal cells lining the wall of ventricles or central canal of spinal cord and their occurrence outside the CNS is extremely rare, published in the literature as case reports or small case series. We present two cases of extra-CNS myxopapillary ependymomas treated at our institution in the past three years; both cases originate in the sacrococcygeal region and were initially misdiagnosed as epidermoid cyst and germ cell tumor, respectively. The first case, which arose in a 9-year-old girl, was treated with a surgical excision in two stages, due to the non-radical manner of the first operation; no recurrence was observed after two years of follow-up. The other case was a 12-year-old boy who was treated with a complete resection and showed no evidence of recurrence at one-year follow-up. In this paper, we report our experience in treating an extremely rare disease that lacks a standardized approach to diagnosis, treatment and follow-up; in addition, we perform a literature review of the past 35 years.

Cerebrospinal fluid and intraoperative squash cytology of childhood ependymoma

Ependymomas are glial neoplasms of central nervous system originated from the ependymal lining of the brain ventricles and spinal cord central canal, and rarely exfoliated into cerebrospinal fluid (CSF). In this case we report the cytomorphological and immunocytomorphological features of ependymoma in CSF and intraoperative squash preparations, confirmed by histology.

Surgical management of a rare myxopapillary ependymoma of the gluteal region: A case report

Background:

Ependymomas are rare tumors originating from neuroepithelial cells lining the wall of the ventricles or central canal of the spinal cord. While these tumors mainly occur within the central nervous system (CNS), there are occasional reports in children and young adult patients with a primary tumor occurrence outside of the CNS. Ependymomas of the sacrococcygeal region have been infrequently described in the literature with no standard of care established. We present a case report and review of the literature regarding this rare entity.

Case Description:

A 24-year-old woman presented with right gluteal pain worsened by sitting and a palpable soft tissue mass of the sacrococcygeal region. Magnetic resonance imaging revealed a 3.7 cm cystic mass centered in the right gluteal region. She underwent a biopsy at an outside institution, with histology revealing myxopapillary ependymoma. The patient was referred to our hospital and underwent an interdisciplinary neurosurgical and orthopedic oncology en bloc resection of the ependymoma, which intraoperatively appeared to originate from the coccygeal nerve.

Conclusion:

In the present report, the authors demonstrate that a myxopapillary ependymoma may present as an isolated gluteal mass attached to the coccygeal nerve, without frank CNS involvement. Furthermore, an interdisciplinary approach to surgical resection of this lesion appears to represent an effective treatment modality.

An unexpected diagnosis of paediatric subcutaneous sacrococcygeal extraspinal ependymoma: lessons learnt and review of the literature

This case describes a 9-year-old male who presented to general surgical clinic with a 3-year history of persistent natal cleft swelling, previously unsuccessfully treated as a pilonidal abscess in the community with multiple courses of antibiotics. In clinic, a 50 × 30-mm soft tissue swelling was found in the natal cleft and a clinical diagnosis of a pilonidal cyst was made. A cream-coloured solid mass measuring 50 × 35 × 30 mm was subsequently excised under general anaesthetic, with specialist histology and immunostaining confirming an unexpected diagnosis of a subcutaneous extraspinal myxopapillary ependymoma, a tumour usually found in the neuraxis. Given the atypical anatomical site of the tumour, the case presented a unique management challenge. Ultimately, the patient underwent a re-operation after specialist multi-disciplinary discussion and is currently disease free at 18 months post-surgery. The authors wish to contribute their experiences of managing this rare extraspinal ependymoma to the few existing reports in the literature.