Cranio-cervical Junction Malignant Extrarenal Rhabdoid Tumor: A Case Report

Case Report: 

A 2-year-old girl was referred with the chief complaint of limb weakness following a mild trauma. She had been suffering from restlessness and neck pain for a month. Laboratory findings were normal. In MRI, there was evidence of craniocervical junction extra-axial mass lesion arising from the posterior aspect of the dense process ligamentous complex extending from the foramen magnum to the posterior fossa with engulfment of the right vertebral artery. Regarding the compressive effect of the tumor, a right trans-condylar suboccipital surgical approach was used to resection the mass, near totally, and decompress the brain stem. Immune-Histo-Chemical Staining (IHC) showed a grade 2 meningioma. Low-dose radiotherapy was applied; but the pathology result corroborated the tumor’s radiologic features. Due to the follow-up MRI evidence of aggressive tumor recurrence the clinical behavior of the tumor and the patient's progression, there was a possibility that the first diagnosis was not correct; hence, a second operation was performed during which a smaller portion of the tumor could be resected compared with the first operation. Pathological study and IHC staining reported MRT and tumor markers, including pan-cytokeratin (CK), epithelial membrane antigen (EMA), and vimentin, were strongly positive. So, a chemotherapy regimen was added to radiotherapy. Unfortunately, the patient did not respond well to the follow-up treatment, and she expired after one year.

In similar cases, where the radiological and pathological features of the tumor are atypical, the histological examination should include molecular examination, as meningioma in this age group is extremely rare. And, confirming the pathological and molecular characteristics of the tumor by different experts is strongly recommended.