Embryonal tumor with multilayered rosettes arising from the internal auditory canal of an adult: Illustrative case with molecular investigations

Embryonal tumors with multilayered rosettes (ETMRs) are aggressive central nervous system (CNS) tumors that usually occur in young children. Here, we describe the first incidence of ETMR in an adult patient that also originated in the novel location of the internal auditory canal (IAC). The 36-year-old patient initially presented with unsteadiness, diplopia, and tinnitus. The tumor in the IAC was discovered on brain magnetic resonance imaging, and gross total resection was performed followed by pathological and molecular diagnosis. The patient received whole brain and spinal cord radiotherapy after an intracranial recurrence and adjuvant chemotherapy consisting of four cycles of ifosfamide, cisplatin, and etoposide. Progression was rapid; however, the patient survived for 22 months after diagnosis before succumbing to the disease. Molecular investigation revealed a DICER1 mutation at exon 25, and methylation classification categorized the tumor as ETMR, non-C19MC-altered. This case underscores the diverse possible presentations of ETMR, DICER1-mutated and the importance of molecular techniques to characterize and promptly treat atypical ETMR.

Trigeminal neuralgia in patients with cerebellopontine angle tumors: should we always blame the tumor? A case report and review of literature

OBJECTIVES

This report seeks to highlight a pitfall that may be encountered in the management of patients with trigeminal neuralgia with imaging showing both neurovascular conflict as well as tumors.

CASE PRESENTATION

A case of a 53 year old male with simultaneous neurovascular conflict and a vestibular schwannoma with trigeminal neuralgia is presented and the management is discussed with reference to managing this particular subset. Pain was noted to be likely generated by neurovascular conflict and not by the tumor, which is usually not the case.

CONCLUSIONS

It is suggested that in such cases, microvascular decompression should always be performed in addition to removal of the tumor.

Preoperative and postoperative high angular resolution diffusion imaging tractography of cerebellar pathways in posterior fossa tumors

This study aimed to utilize high angular resolution diffusion magnetic resonance imaging (HARDI) tractography in the mapping of the pathways of the cerebellum associated with posterior fossa tumors (infratentorial neoplasms) and to determine whether it is useful for preoperative and postoperative evaluation. Retrospective data from 30 patients (age 2-16 yr) with posterior fossa tumor (17 low grade, 13 high grade) and 30 age-sex-matched healthy controls were used. Structural and diffusion-weighted images were collected at a 3-tesla scanner. Tractography was performed using Diffusion Toolkit software, Q-ball model, FACT algorithm, and angle threshold of 45 degrees. Manually assessed regions of interest were placed to identify reconstructed fiber pathways passing through the superior, medial, and inferior cerebellar peduncles for the preoperative, postoperative, and healthy control groups. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and track volume measures were obtained and analyzed. Statistically significant differences were found between the preop/postop, preop/control, and postop/control comparisons for the volume of the tracts in both groups. Displacement and disruption of the pathways seemed to differ in relation to the severity of the tumor. The loss of pathways after the operation was associated with selective resection during surgery due to tumor infiltration. There were no FA differences but significantly higher ADC in low-grade tumors, and no difference in both FA and ADC in high-grade tumors. The effects of posterior fossa tumors on cerebellar peduncles and reconstructed pathways were successfully evaluated by HARDI tractography. The technique appears to be useful not only for preoperative but also for postoperative evaluation.

Rotational Occipital Scalp Flap for Occipital Pressure Ulcer

Occipital pressure ulcers and wound gaping may occur in unconscious and malnourished patients. Most of the time, a large defect requires wound coverage by scalp flaps. This video describes a rotational occipital scalp flap for occipital pressure ulcer and wound gaping in a patient of operated midline posterior fossa mass & ventriculoperitoneal shunt. The defect measured 2.25 × 2.5 cm with exposed inion. The wound was included in an imaginary triangle, and the horizontal and vertical incision lengths were about four times the base of the triangle. The flap was based on the left occipital artery and raised in an avascular plane above the periosteum. The wound margins were freshened and undermined. The flap was rotated to bring it over the defect, and suturing was done in the standard manner. The flap had good healing, and the patient continued to be under care for his cerebellar medulloblastoma.

A giant fourth-ventricular tuberculoma mimicking a primary posterior fossa tumor

Typically, an intracranial tuberculoma occurs within the brain parenchyma. Intraventricular tuberculomas are rare in the absence of systemic tuberculosis (TB), and the differential diagnosis between tuberculoma and other lesions, such as primary brain tumors, can be difficult. We report an extremely unusual case of solitary fourth-ventricular tuberculoma, which occurred in a 3-year-old female patient, with no indication of TB. This lesion appeared as a primary intraventricular tumor in the fourth ventricle in both clinical and radiological examinations. In this scenario, a surgical treatment option was pursued. Histopathological testing supported the diagnosis of tuberculoma. The patient was subsequently treated with 18 months' therapy for tuberculous, without adverse events.