title: Non-sarcomatous spindle cell morphology in conventional lung adenocarcinoma: a clinicopathological study.
abstract: Non-sarcomatous spindle cell foci (N-SSCF) without aggressive invasiveness, also called morule-like lesions, occur occasionally in conventional lung adenocarcinoma, but their characteristics remain poorly understood. We identified N-SSCF in 7 (4.0 %) of 173 lung adenocarcinomas and examined their clinicopathological features. The patients were six men and one woman with a mean age of 57.0 years (range, 43-76 years). All tumors were papillary-predominant adenocarcinomas, ranging in size from 1 to 4.5 cm (mean, 2.7 cm). N-SSCF occupied 10-30 % of the tumors, and in all cases, there were focal or multifocal transitions between the two morphotypes. Most N-SSCF were plug-like nodules filling the spaces of cancerous alveoli/tubules or patchy insular nests. N-SSCF frequently contained mucin + lumina and were positive for cytokeratin 7, thyroid transcription factor 1, and Napsin A, but negative for cytokeratin 5/6 and vimentin, similar to the adenocarcinoma cells of the same tumor. Five cases (71 %) were at stage I or II, suggesting that N-SSCF can occur in an early phase of lung cancer. In an age-, sex-, and stage-matched control study, N-SSCF were not associated with prognosis (P = 0.471). We consider tumors with N-SSCF a distinct structural variant of adenocarcinoma without prognostic significance. They should be distinguished from true sarcomatous spindle cells and micropapillary components, which are associated with aggressive behavior.
authors.affiliation: Department of Pathology, Japan Self-Defense Forces Central Hospital, 1-2-24 Ikejiri, Setagaya-ku, Tokyo, 154-8532, Japan, skuma@cocoa.plala.or.jp.
authors.forename: Susumu
authors.initials: S
authors.lastname: Matsukuma
authors.forename: Kiyohaya
authors.initials: K
authors.lastname: Obara
authors.forename: Kimi
authors.initials: K
authors.lastname: Kato
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Ohshika
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takeo
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsuchiya
authors.forename: Kimiya
authors.initials: K
authors.lastname: Sato
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D053552:Keratin-7 / Q000378:metabolism; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009687:Nuclear Proteins / Q000378:metabolism; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D053552:Keratin-7; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D016282:Aspartic Acid Endopeptidases; C498549:NAPSA protein, human