The cytologic features of NUT midline carcinoma

• Published in: Cancer 2009-12, Vol.117 (6), p.508-515
• Main Authors: Bellizzi, Andrew M., Bruzzi, Cynthia, French, Christopher A., Stelow, Edward B.
• Format: Article
• Language: English
• Subjects: Adult; Aged; aggressive carcinoma; Bacterial Translocation; BRD4; Carcinoma - genetics; Carcinoma - pathology; Chromosomes, Human, Pair 15; cytology; Diagnosis, Differential; differential diagnosis; Female; fine‐needle aspiration; fluorescent in situ hybridization; Humans; immunohistochemistry; Laryngeal Neoplasms - pathology; Male; Nasal Cavity; Nose Neoplasms - genetics; Nose Neoplasms - pathology; Nuclear Proteins - genetics; NUT midline carcinoma; t(15; 19); undifferentiated carcinoma
• ISSN: 1934-662X; 0008-543X; 1934-6638
• DOI: 10.1002/cncy.20044

BACKGROUND: Nuclear protein in testis (NUT) midline carcinoma (NMC) represents an aggressive, high‐grade carcinoma typically involving the upper aerodigestive tract or mediastinum. Although the tumor was originally noted in young persons, we have subsequently identified 5 adult cases. To our knowledge, the cytology of NMC has not been systematically described. METHODS: We recently published a series of NMCs identified by fluorescent in situ hybridization for characteristic NUT rearrangement. Three of these patients had undergone fine‐needle aspiration. Patient age, sex, primary tumor location, and aspiration site were noted. Cases were assessed for the following: cellularity, architecture, cytoplasm, cell size, nuclear contours, nucleoli, chromatin, anisonucleosis/cytosis, mitotic activity, background, and nuclear crush. RESULTS: The 3 cases occurred in 2 women and 1 man, ages 31‐79 years. Primaries involved the sinonasal tract (2) and larynx. Aspirates were of right neck masses (2) and supraclavicular lymph node. Smears were highly cellular and generally noncohesive. Cytoplasm was scant/delicate, although occasional cells with denser cytoplasm were noted in 1 case. Cells were 2‐3 times the diameter of a small lymphocyte with irregular nuclear contours, discrete nucleoli, and fine/granular to vesicular chromatin. Anisonucleosis/cytosis was slight to moderate. Mitotic figures were noted in each case. The background contained naked nuclei and karyorrhectic debris; nuclear crush was noted. CONCLUSIONS: NMCs exhibit cytologic features of a poorly differentiated or undifferentiated carcinoma. Although reports mention squamous differentiation as a histologic feature, it is typically focal, and overt squamous differentiation was not identified in our cases. Given morphologic overlap with other high‐grade carcinomas, diagnosis requires a high index of suspicion. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society. NUT midline carcinoma, a clinically aggressive, high‐grade “translocation carcinoma,” is being increasingly recognized. Knowledge of this entity should allow for the triaging of cytology specimens for the ancillary testing required to make the diagnosis.