Diagnosis of high‐grade pulmonary neuroendocrine carcinoma by fine‐needle aspiration biopsy: Nonsmall‐cell or small‐cell type?

Abstract

A consensus optimal therapy for large-cell neuroendocrine carcinoma of the lung has not been achieved since this entity was proposed in 1991. Accumulation of clinical data and investigation, however, can be greatly impeded by erroneous cytological diagnosis, based on which treatment may be initiated. To avoid erroneous diagnoses, cytological criteria need to be defined. Twenty cases of fine-needle aspiration specimens with a diagnosis of neuroendocrine tumor by either cytology or follow-up histology were retrospectively reviewed for cytomorphologic features. Patients' clinical data were also reviewed. Three cytomorphologic patterns were identified for large-cell neuroendocrine carcinoma, i.e., nonsmall-cell-like, small-cell-like and, mixed nonsmall-cell-small-cell-like. Small-cell-like large-cell neuroendocrine carcinoma can be mistaken for small-cell carcinoma. The most important differential features between these two entities are nuclear size and perceptibility of nucleoli of tumor cells.

Fine-needle aspiration cytology of large cell neuroendocrine carcinoma of the lung

“…Another study by Hiroshima et al14 described 25 cases (14 touch imprints and 11 brush specimens). Except for cellular palisading, the cytologic features noted in their study are similar to those described by others 9–13. The current study findings showed the greatest similarities with those described by Wiatrowska et al10 and Kakinuma et al12 The presence of nucleoli was the most significant difference noted among studies.…”

“…In their series of 22 cases, only 2 were misdiagnosed as SCC. Yang et al11 analyzed 4 histologically proven cases. To differentiate them from SCC, they emphasized cell size and the presence of nucleoli.…”

Clinical responses of large cell neuroendocrine carcinoma of the lung to cisplatin-based chemotherapy

“…Of the 87 patients, only five who had received cisplatin-based chemotherapy for recurrent tumor that was evaluable for the response. While LCNEC is difficult to diagnose prior to the start of treatment on the basis of the findings in biopsy or cytological specimens, the architectural neuroendocrine features may, more or less, be reflected in these small samples [19,20]. We, therefore, conducted a review of 567 autopsy cases of lung cancer, and identified 15 cases of LCNEC who had received cisplatin-based chemotherapy.…”

Respiratory cytology: Differential diagnosis and pitfalls

“…[73][74][75][76] The most characteristic features included necrotic background, three-dimensional clusters with peripheral palisading, scant or moderate cytoplasm, oval nuclei with finely or coarsely granular chromatin, small to prominent nucleoli and irregular thickened membranes, showing some molding and crush artifact. No single morphologic feature is diagnostic, but rather the set of cytomorphologic findings together with immunohistochemistry staining for neuroendocrine markers, particularly synaptophysin, may allow the correct diagnosis of LCNEC.…”