Primary Central Nervous System Post-transplant Lymphoproliferative Disorder Misdiagnosed as Glioblastoma: A Case Report.

Background/aim: Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous lymphoid cell disorder that occurs after solid organ and hematopoietic stem cell transplantation. Primary occurrence in the central nervous system PTLD (PCNS PTLD) is rare. We present a rare case of PCNS-PTLD misdiagnosed as glioblastoma (GBM).

Case Report: A 62-year-old man underwent living-related kidney transplantation at the age of 49. He was introduced to our Department because of transient speech disturbance. Computed tomography scan of the head showed a mass at the right frontal lobe. Magnetic resonance imaging (MRI) of the head showed a ring-enhancing lesion with a small, homonymous enhanced lesion in the right frontal lobe, invading the corpus callosum. Because the pathological analysis of an intraoperative frozen section of the tumour indicated high-grade glioma, the tumour was completely resected and BCNU wafers were implanted at the resection site. However, postoperative pathological analysis indicated a diffuse large, CD20 positive B-cell lymphoma. In addition, the patient was positive for Epstein Barr virus-encoded small RNA, and therefore, diagnosis of PCNS PTLD was confirmed. The dose of the immunosuppressant therapy was reduced, and rituximab monotherapy was begun.

Conclusion: Both imaging and pathological findings on intraoperative frozen section of PCNS PTLD are similar to those of GBM. Therefore, in such cases, surgeons should consider PCNS-PTLD when the diagnosis indicates GBM.