[351] The Cytomorphological Evaluation of Large Cell Neuroendocrine Carcinoma of the Lung in Aspiration and Exfoliative Cytology.

Xiangbai Chen, Sara E Monaco, Walid E Khalbuss, Chengquan Zhao. Conemaugh Memorial Hospital, Johnstown, PA; UPMC, Pittsburgh, PA

Background: Large cell neuroendocrine carcinoma (LCNEC) of the lung is a pulmonary neuroendocrine tumor that is considered to be an aggressive non-small cell carcinoma, and within the spectrum of neuroendocrine tumors in the lung, which includes carcinoid, atypical carcinoid and small cell carcinoma. The correct diagnosis of LCNEC in cytologic specimens is important for prognosis and management. Although the histologic criteria for LCNEC of the lung are well established, studies on the cytomorphological features are limited.
Design: The surgical pathology files were searched for pulmonary LCNEC from January 2001 to September 2010. From a total of 54 cases histologically diagnosed as pure LCNEC, 27 patients had cytological evaluation before surgical excision and were included in this study. The cytologic specimens included 12 fine needle aspiration (FNA) biopsies and 15 bronchial brush (BB) or bronchial wash (BW) specimens. The available cytologic specimens were reviewed by two cytopathologists.
Results: 16 patients were men and 11 were women. The mean age was 62.2 years ranging from 44 to 86 years. Original cytologic diagnoses of all 27 patients were as following: 3 LCNEC, 3 non-small cell carcinomas (NSCLC), 4 small cell carcinomas, 5 poorly differentiated carcinomas, 5 atypias, and eight negatives. 10/12 (83%) FNA biopsies were reported as positive for malignancy. In contrast, only 4/15 (27%) BW/BB specimens were reported as positive for malignancy. 14 cytologic specimens diagnosed as positive were available for review. Variable cytologic features are listed in Table 1.

Conclusions: Our results illustrate that LCNECs are uncommon NSCLCs that can be difficult to evaluate in cytological material, particularly in exfoliative or brushing cytology. However, in a tumor of non-small cell type without definitive squamous or glandular differentiation, the presence of intermediate to large nuclei, marked pleomorphism, high N/C ratio, and nuclear molding, one should consider incorporation of neuroendocrine markers in the immunopanel, which may enhance the ability to identify these cases. This is important given the poor prognosis of LCNEC carcinomas within NSCLCs, and the potential for tailoring the treatment for these patients.
Category: Cytopathology

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 74, Tuesday Morning


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