Implications for differential diagnosis of lung cancer-associated lymphadenopathy in lymphoepithelioid cell lymphoma (Lennert's lymphoma) arising simultaneously with lung cancer: a case report.

ABSTRACT

BACKGROUND: Lymphoepithelioid cell lymphoma (LCL) is a rare morphologic variant of peripheral T-cell lymphoma, and its cytologic features have not been well characterized. We describe details from fine needle aspiration cytology (FNAC) of LCL in a patient simultaneously suffering from lung cancer, in whom extensive lymph node metastasis was suspected clinically. CASE A 54-year-old man had a lung nodule diagnosed as an adenocarcinoma by biopsy. 18F-fluoro-deoxyglucose positron emission tomography showed high uptake in the lung nodule as well as interlobar, supraclavicular and axillary lymph nodes. FNAC from interlobar and supraclavicular lymph nodes revealed abundant lymphoid cells intermingled with epithelioid cell clusters. Most lymphoid cells were small, with teardrop-shaped nuclei. Occasionally, large lymphoid cells with hyperconvoluted nuclei and prominent nucleoli were observed. An extensive sarcoid reaction was suspected on cytology, and lobectomy was performed. LCL with lung adenocarcinoma was diagnosed on the immunohistochemical findings. CONCLUSION: Detailed observation of lymphoid cells with FNAC is important even in patients with lung cancer and massive regional lymphadenopathy. Presence ofa teardrop nuclear shape and nuclear irregularities of lymphoid cells provides important information for cytologic diagnosis of LCL when epithelioid cell clusters are evident.