Cytological diagnosis of metastatic glioblastoma in the pleural effusion of a lung transplant patient.

The extracranial metastasis of glioblastoma is a rare event. We report the case of a patient who developed metastatic glioblastoma in pleural effusion 15 months after lung transplant, with emphasis on differential diagnosis based on cytological material. In our case, tumor cells had pleomorphic nuclei, prominent nucleoli, and fine vesicular chromatin. Some were arranged in a poorly formed pseudo-glandular architecture, mimicking a poorly differentiated adenocarcinoma. The cytological diagnosis of metastatic glioblastoma is difficult and depends critically on clinical history and suspicion, particularly in the transplant setting. Review of the literature indicates that transmission/metastasis of intracranial malignancy occurs rarely following organ transplantation, with some debate on the suitability for transplant of organs from affected donors. Although the situation is uncommon, this report of the cytological findings of extracranial glioblastoma may extend our current knowledge and provide additional differential diagnostic information for this entity.