17. Pathology Division
The research activities of the Pathology Division of the Research Institute, East are centered on morphological studies of cancer tissue. Major projects include quality control of pathological diagnosis, clinico- pathological assessment of cancers and the pathology of precancerous lesions and early cancers.
Morphological Diagnosis by Image Analysis and Artificial Intelligence
For the purpose of developing a computer-assisted image diagnosis system, image analysis data from neoplastic and proliferative lesions of the breast were analyzed by means of artificial intelligence. In 1996, intraductal carcinoma and benign proliferative lesions of the breast were examined utilizing this system. These lesions can be difficult to differentiate from each other by light microscopy alone. Numerical image data were extracted with a computer-assisted image analysis system and fed to the artificial intelligence to construct a neural network for the differential diagnosis of benign and malignant lesions. Data from one case each of typical benign and malignant lesions were used as a teaching set for the construction of the neural network. Then, the differential ability of the neural network was tested by comparing the results with the diagnosis made by pathologists. First, 42 cases, including both benign and malignant intraductal lesions, were examined independently by three experienced pathologists. They classified the lesions as benign, malignant or borderline. Then, the same lesions were analyzed by the computer-assisted system. The agreement rate for diagnoses by pathologists and the computer-assisted system was about 80%. The computer-assisted system failed to correctly diagnose lesions significantly different from the teaching cases used to construct the diagnostic program.
Clinicopathological Study of Intraductal Neoplasm and Mucinous Cystic Neoplasm of
the Pancreas
Intraductal neoplasm and mucinous cystic neoplasm of the pancreas are often confused with each other because their neoplastic cells are similar. We studied 28 cases of intraductal neoplasm and 10 cases of mucinous cystic neoplasm and compared their clinicopathological characteristics. The former showed male predominance and occurred in the pancreatic head, while the latter developed only in females and the body and tail were the locations of the neoplasm. One of the patients with mucinous cystic neoplasm died of the tumor but those with intraductal neoplasm did not die of the disease within the follow-up period. When intraductal papillary carcinoma became invasive, it showed the histology of mucinous carcinoma. This invasion was probably induced by leakage of mucin into the stroma via increased pressure within the dilated ducts or a change in the direction of mucin secretion by the tumor cells. It therefore does not have the appearance of true invasion. Both types of tumors represent an indolent subtype of pancreatic neoplasms and are clearly distinct from the highly malignant form usually found in the pancreas.
Fibrotic Focus in Invasive Ductal Carcinoma of the Breast
When the primary tumor of recurrent breast cancer is reviewed, a fibrotic focus is often recognized. Therefore, the clinicopathological significance of the presence of a fibrotic focus in breast cancer has been studied. It became apparent that invasive ductal carcinomas with a fibrotic focus or foci had an at least six times higher relative risk of early recurrence, i.e., within 3 years after surgery, and all tumors in the patients who died within 3 years had a fibrotic focus.(166) This correlation was maintained even in conducting the analysis based solely on the patients with early stage breast cancer (Stages I and II). These data indicate that the presence of a fibrotic focus is a marker of high aggressiveness in invasive ductal carcinoma of the breast.
Development of a Prototype for Exhibiting Educational Pathology Images on the Internet
Pathology images of interesting or rare cases are to be presented on the Internet for educational purposes. To meet this aim, a prototype was developed using the html format. The cases will be presented as a short case report including a brief clinical description, gross and microscopic images with explanations and a concise discussion with a reference list.
Clinicopathological Studies of Various Cancers
Prognostic factors and other clinicopathological characteristics of various cancers have been studied in collaboration with clinical departments of the two hospitals affiliated with the National Cancer Center. In addition to case reports,(167-170) clinicopathological studies of lymphoma,(171) esophageal cancer,(172) pancreatic cancer(173-177) and malignant melanoma(178) were conducted and clinically important information has been obtained.
List of papers from this division
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