Toshio Kumasaka

Publications (2)3.25 Total impact

• Article: Rare pneumoconiosis induced by long-term amorphous silica exposure: the histological characteristics and expression of cyclooxygenase-2 as an antifibrogenic mediator in macrophages.

  Toshio Kumasaka, Yasushi Akaike, Osamu Nakamura, Kazuma Yamazaki, Hiroshi Moriyama, Tamiko Takemura
  [show abstract] [hide abstract]
  ABSTRACT: Pneumoconiosis induced by non-crystalline silica is considered rare, although silicosis resulting from contact with crystalline silica is a well-known hazard associated with progressive pulmonary fibrosis. Here we describe a patient with pneumoconiosis induced by diatomaceous earth composed of amorphous silica detected by two-dimensional imaging of chemical elements. The histology revealed that the disease was characterized by a granulomatous reaction in the lung. A large number of macrophages laden with yellow and black pigments accumulated in alveolar spaces and were incorporated into the interstitial sites. Bronchiolar walls were destroyed by palisade macrophages, suggesting airflow obstruction. Packed macrophages adhering to and covering the denuded interstitium indicated that macrophages might be incorporated into pulmonary interstitium in this fashion. Immunohistochemistry showed that cyclooxygenase-2, an antifibrogenic mediator, was intensely expressed in the macrophages compared with macrophages in control lungs. No birefringent material was found in the tissues. When two-dimensional analysis of chemical elements was performed using an electron probe microanalyzer with a wavelength-dispersive spectrometer, the resultant fine mapping of silicon and oxygen on the tissue indicated that the pigments phagocytosed by macrophages corresponded to amorphous silica. In conclusion, two-dimensional analysis of elements is very useful for pathologists in correlating the presence of chemical elements with histological changes.
  Pathology International 11/2011; 61(11):667-71. · 1.62 Impact Factor
• Article: Mixed squamous cell and glandular papilloma of the lung: a case study and literature review.

  Kentaro Inamura, Toshio Kumasaka, Reiko Furuta, Kei Shimada, Noriko Hiyama, Yoshiaki Furuhata, Isao Tanaka, Tamiko Takemura
  [show abstract] [hide abstract]
  ABSTRACT: Mixed squamous cell and glandular papilloma (mixed papilloma) of the lung is an extremely rare neoplasm, with only 10 cases reported so far in the English literature. We present a case study of endobronchial mixed papilloma with immunohistochemical and etiological investigations. A 49-year-old male with a smoking history complained of hemoptysis, presented with a lung mass closely adjacent to large vessels in the computed tomography findings, and underwent lobectomy. The 3.0-cm sized polypoid tumor was histologically diagnosed as endobronchial mixed papilloma. Immunohistochemically, intracellular mucin was positive for MUC5AC, which is expressed in tracheobronchial goblet cells. CAM5.2 and CK19 were diffusely positive, indicating that the tumor originated from the columnar epithelium by squamous metaplasia. CEA and CA19-9 were focally positive. A human papillomavirus (HPV) investigation with in situ hybridization using a wide spectrum probe and a newly-developed PCR system did not detect any HPV infection. Including this case with a detailed HPV investigation, all of the reported cases of mixed papilloma were HPV-negative, and a literature review including newly-reported cases indicated a high frequency of smoking in such cases. Endobronchial mixed papillomas might have a smoking-related etiology.
  Pathology International 04/2011; 61(4):252-8. · 1.62 Impact Factor