gms | German Medical Science

Objective: After the first recent descriptions of H3F3A K27M mutation detected in pilocytic astrocytomas in adult patients, there is a discrepancy regarding the prognostic influence of this mutation in low-grade gliomas in view of the latest WHO classification of central nervous system tumors and its therapeutic consequence. So far only short-term courses are known. To our knowledge, this is the first case of a pilocytic astrocytoma with detected H3F3A K27M mutation in an adult patient with a long-term follow-up.

Methods: Here we describe a case of a 34 year old male presenting with a hemihypesthesia subTh8 on the right and a progressive myelopathy in 2008. MRI showed a T2-hyperintense contrast-enhancing intramedullar formation on level T10/11. After resection of the tumor, histopathological diagnosis confirmed a pilocytic astrocytoma WHO grade I and no further treatment was administered. After local recurrence in 2013 the patient received adjuvant radiotherapy. With further progression on MRI six months later, re-resection was performed with histological proof of a pilocytic astrocytoma WHO Grade I. In 2016, dysesthesia of the upper extremities occurred, revealing diffuse progression from the cervical spine to the brainstem. An open biopsy in 2017 confirmed H3F3A K27M mutation and palliative radiochemotherapy with temozolomide was initiated which was extended to the cerebrum after detection of two cerebral lesions but had to be aborted due to clinical deterioration. The patient died 10 days later.

Results: On immunohistochemical analysis we were able to verify a H3F3A K27M mutation in the last as well as the initial specimen of 2008, which led to the integrated diagnosis of a diffuse midline tumor WHO grade IV without MGMT promotor methylation.

Conclusion: Pilocytic astrocytomas should be routinely screened for the H3F3A K27M mutation to investigate its relevance as a prognostic factor and influence on treatment strategies.