We describe a case of glioblastoma multiforme (GBM) with pleuropulmonary metastasis in whom diagnosis was made with bronchoscopic tranbronchial needle aspiration.
A 63-year-old man referred for evaluation of pleural effusion and lung mass. Initial work up of dyspnea with CXR, CT scan and thoracentesis was done outside. The CT scan of the chest showed a mass and pleural effusion (Figure 1). The effusion was exudative with no malignant cells. CXR from last year was normal. Physical examination revealed findings suggestive of pleural effusion. GBM was diagnosed 18 months ago and treated with surgery and chemoradiation. Despite therapies, he had residual tumor that had remained stable. He has a smoking history of 10-pack year. The day after presentation to our hospital, he underwent bronchoscopy that revealed a distorted RUL bronchus with extrinsic compression of the distal trachea. Multiple transbronchial needle aspirates through the distal trachea were performed. Preliminary diagnosis of non-small cell was made on-site cytology evaluation. Three days later, a repeat thoracentesis was again negative for malignant cells. The smears of fine needle aspirates showed with ill-defined cells and cytological features overlapping with poorly differentiated non-small cell carcinoma of lung. Immunophenotyping on cellblock ruled out lung primary, paragangliomas and melanoma. Tumor cells were reactive for CD56 and positivite for glial fibrilary acidic protein (GFAP) confirming metastatic GBM (Figure 2). After the diagnosis, palliative treatment options were discussed with the patient. He decided not to proceed with any treatment and died in 6 weeks.
Although GBM is a locally invasive tumor, distant metastasis is rare. Incidence of metastatic GBM is 0.44% (1). Various organ involvements have been described (2345678910111213). The low incidence attributed to absence of cerebral lymphatics, occlusion of draining venous channels and short survival. Common characteristic feature is prior debulking surgeries in most cases (4, 14). There have been more reports of metastatic cases with gliosarcoma, a variant of GBM (1, 2, 567) DNA studies suggested that systemic metastasis in glioblastoma may represent the emergence of neoplastic subclones (8). Ueda showed the similar patterns of gene expression in primary and metastatic tumors, suggesting the direct infiltration of tumor cells into extracranial blood vessels (3). Pleuropulmonary metastasis of GBM has been reported in 10 cases in the English literature (1,2, 567). Of 8 cases had gliosarcoma. The secondary metastatic GBM case (3) found to have lung metastasis on autopsy. Greif (2) published a case who developed pleural effusion and lung mass after surgery. They made the diagnosis by percutaneous core needle biopsy. Because of the location of the mass, we elected to perform bronchoscopy. Our initial clinical impression was primary lung cancer. Immunophenotyping studies confirmed diagnosis of metastatic GBM. This is the first case in whom lung metastasis diagnosed with needle aspitation. Because of the low number of cells obtained by needle aspirates and similarities of the glioblastoma tumor cells to poorly differentiated other tumors, preparation of cellblock for further immunophenotyping studies may improve the diagnosis of metastatic GBM.
Pleuropulmonary metastasis of GBM can be made with transbronchial needle aspirates. Early diagnosis and palliative treatment may have impact on survival.
N. Gupta, None.