title: Cytology of basaloid squamous carcinoma of the bronchus. A case report.
abstract: BACKGROUND
  The cytologic appearance of basaloid squamous carcinoma (BSC) arising in the lower respiratory tract has not been described very well because of its rarity. This article describes a surgical case of bronchial BSC and provides the first documentation of the sputum and imprint cytologic features of the tumor.
  
  
  METHODS
  A 74-year-old man presented with hemoptysis. An abnormal intrabronchial mass was revealed by computed tomography and bronchoscopy. Preoperative cytology and biopsy showed that the mass was composed of small, round, atypical cells, but correct diagnosis was difficult. Under a tentative diagnosis of small round cell carcinoma, a right lobectomy was performed. The resected tumor was composed of small cells showing peripheral palisading and partial epidermoid differentiation. There was no glandular differentiation. Focal necrosis was also noted. Immunohistochemical markers for smooth muscle and neuroendocrine cells were negative. The tumor was eventually diagnosed as BSC or basaloid carcinoma (BC) with squamous differentiation.
  
  
  CONCLUSIONS
  It is important to recognize this disease, especially when undetermined small round cell carcinoma is noted in cytologic specimens, in order to properly assess prognosis. Cytologic detection of nuclear palisading of the neoplastic cells, one of the hallmarks of the disease, may be difficult, however, careful examination to reveal neoplastic cells showing squamous differentiation appears helpful for diagnosis.
authors.affiliation: Department of Pathology, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Inayama
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yoshida
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hayashi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Takahashi
authors.forename: Nobuo
authors.initials: N
authors.lastname: Ogawa
authors.forename: Shigeki
authors.initials: S
authors.lastname: Odagiri
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nakatani
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D001984:Bronchial Neoplasms / Q000473:pathology*; D002281:Carcinoma, Basosquamous / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002454:Cell Differentiation; D006801:Humans; D008297:Male