AB043. Pleural effusion: a common symptom reveals a rare neoplasm

Background: The case of a male patient, 25, who presented with pleural effusion. Further imaging examinations demonstrated mediastinal and cervical lymphadenopathy.

Methods: The cytologic examination of pleural effusion described an increased number of T-lymphocytes, suggesting further investigation of the patient. A left-sided cervical lymph node was resected, 2 cm in greatest diameter, which was microscopically examinated.

Results: The architectural structure of the lymph node was completely destroyed, due to the presence of neoplastic lymphoid cells, mainly medium-sized, in compact growth pattern. They contained little cytoplasm, with a high nucleus-to-cytoplasm ratio, oval nuclei, with distinct nucleoli and condensed chromatin. Mitoses were frequent, while necrosis was absent. The neoplastic cells infiltrated the adjacent fat tissue. Immunochemistry revealed the following immunophenotype: CD7+++, CD79a+++, TdT+++, CD99+++, CD43+++, CD10++/−, Bcl 2+++, CD34+ (scarce—faint), CD3+/− (faint), CD5+/− (faint), CD4−, CD8−, CD45RO−, CD1a−, CD20−, Pax5−, CD19−, CD23−, CD30−, Bcl 6−, CD15−, CD68−, CD117−, MPO−, CD56−, MUM1−, Alk−. The proliferation marker Ki67 was expressed by 90–95% of the neoplastic cells. According to the above, the diagnosis was a T-lymphoblastic lymphoma/leukemia (T-LBL). The patient received chemotherapy, but unfortunately died 7 months after the diagnosis.

Conclusions: Lymphoblastic lymphoma accounts for 1–2% of non-Hodgkin lymphomas, and T-lymphoblastic lymphoma is the most common of those. It is a highly aggressive neoplasm, which occurs more often in men, usually during adolescence or young adulthood. Typical clinical manifestations include pleural effusion and mediastinal lymphadenopathy. However, the cytologic examination of the pleural effusion is, more often than not, unable to state the final diagnosis. Only 10% of the lymphomas affecting the mediastinum are primary, and, among those, T-lymphoblastic lymphoma is extremely rare. In this case, the cytologic examination of pleural effusion arose the suspicion of a lymphoma, resulting in further investigation and lymph node microscopic examination, which led to the final diagnosis.

Keywords: Mediastinal lymphadenopathy; cervical lymphadenopathy; pleural effusion