ABSTRACT
Hepatic lymphoma is a rare disease with poor prognosis because of delayed diagnosis. The disease comprises primary, metastatic, and intravascular hepatic lymphomas. The pathological characteristics of lymphomas differ contributing to difficulty in early diagnosis. Early diagnosis and appropriate treatment result in improved prognosis; therefore, diagnostic radiology and its development with various contrast agents are critical for improving disease outcomes. Herein, we review hepatic lymphomas and summarize the results of imaging studies in correlation with pathological characteristics. The information provided will help physicians in early diagnosis and thereby improving prognosis.
Subject(s)
Diagnostic Imaging/methods , Liver Neoplasms/diagnosis , Lymphoma/diagnosis , Humans , Liver Neoplasms/classification , Lymphoma/classificationABSTRACT
BACKGROUND: Gastric neuroendocrine neoplasia has been classified as neuroendocrine tumor (NET), a less-malignant type, and neuroendocrine carcinoma (NEC), a more-malignant type. We investigated phenotypic expression profiles to clarify the differences between NET and NEC in terms of histopathology and carcinogenesis. METHODS: We assayed 86 cases of gastric neuroendocrine neoplasms (NET G1, n = 25; NET G2, n = 9; NEC, n = 52), using six exocrine markers (MUC5AC, human gastric mucin, MUC6, M-GGMC-1, MUC2, and CDX2). RESULTS: NEC frequently coexisted with adenocarcinomatous components (75 %; 39 of 52) and the majority (71.8 %; 28 of 39) showed intraglandular endocrine cell hyperplasia, although no cases of NET showed adenocarcinomatous components. Mucin phenotype significantly differed between NET and NEC; none of NET cases expressed any exocrine markers other than CDX2, although the majority of NEC (86.5 %; 45 of 52) expressed at least one or more exocrine markers with various positive rates for each marker (range, 8.2-74.0 %). Each NEC component showed only the phenotype expressed in the adenocarcinomatous component in the same tumor. Furthermore, double immunohistochemistry revealed dual expression of CDX2 and chromogranin A in half the NEC cases (23 of 46). CONCLUSIONS: These data suggest that gastric NETs (G1 and G2) and NECs have different processes of carcinogenesis, and gastric NECs may be generated from preceding adenocarcinomas.
Subject(s)
Adenocarcinoma/pathology , Biomarkers, Tumor/metabolism , Carcinoma, Neuroendocrine/pathology , Neuroendocrine Tumors/pathology , Stomach Neoplasms/pathology , Adenocarcinoma/metabolism , Adult , Aged , CDX2 Transcription Factor , Carcinogenesis , Carcinoma, Neuroendocrine/metabolism , Female , Follow-Up Studies , Gastric Mucins/metabolism , Homeodomain Proteins/metabolism , Humans , Immunoenzyme Techniques , Male , Middle Aged , Mucin 5AC/metabolism , Mucin-2/metabolism , Mucin-6/metabolism , Neoplasm Staging , Neuroendocrine Tumors/metabolism , Phenotype , Prognosis , Stomach Neoplasms/metabolismABSTRACT
The enzyme alpha-methylacyl-coenzyme A racemase plays an important role in the beta-oxidation of branched-chain fatty acid and its derivatives. It has been used to detect prostatic adenocarcinoma and high-grade intraepithelial neoplasia, and recently also as a marker for other neoplasms, including those of the genitourinary system, breast, upper and lower gastrointestinal tract and their precursor lesions. We assessed expression of alpha-methylacyl-coenzyme A racemase by immunohistochemistry in neuroendocrine tumours of the stomach to determine differences in the incidence and pattern of expression among different types of gastric neuroendocrine tumours. While none of the grade 1 neuroendocrine tumours were immunoreactive, 67 % of grade 2 neuroendocrine tumours and 90 % of neuroendocrine carcinomas were positive for alpha-methylacyl-coenzyme A racemase. Furthermore, an adenocarcinoma component was found in 72.5 % (37 of 51) of neuroendocrine carcinomas, whereas none of the grade 1 and 2 neuroendocrine tumours contained an adenocarcinoma component. In 83 % of neuroendocrine carcinomas, the adenocarcinoma component was positive for alpha-methylacyl-coenzyme A racemase, and both adenocarcinoma and neuroendocrine carcinoma components stained positively in 78 % of these cases. Our results indicate that alpha-methylacyl-coenzyme A racemase is a useful marker for distinguishing between grade 1 (negative) and grade 2 neuroendocrine tumours, and neuroendocrine carcinoma of the stomach (frequently positive). Different patterns of alpha-methylacyl-coenzyme A racemase expression between gastric neuroendocrine tumours and neuroendocrine carcinoma suggest that these might develop via different tumourigenic pathways.
