title: Micropapillary carcinoma of stomach: a clinicopathologic and immunohistochemical study of 11 cases.
abstract: Micropapillary carcinoma (MPC) of the stomach is a rare, newly recognized entity, and only 2 patients with this histology have been reported. We investigated clinicopathologic features, expression of mucin (MUC2, MUC5AC, MUC6, CD10) and cytokeratin profiles (CK7 and CK20), epidermal growth factor receptors (EGFR and HER2), prognostic markers (p53 and Ki-67), and outcomes in 11 MPCs of the stomach. The proportion of MPC component ranged from 5% to 70%. Micropapillary features were often found at the deep advancing edge of the tumor. Endolymphatic tumor emboli were found in 10 cases (91%) and lymph node metastases were found in 4 cases (36%). In MPCs, positive expression was observed for Ki-67 (82%), CK7 (73%), EGFR (64%), p53 (64%), MUC5AC (45%), MUC6 (36%), and CK20 (27%). However, MUC2, CD10, and HER2 expression was negative in all cases. In 9 conventional adenocarcinomas and 11 papillary adenocarcinomas with multiple endolymphatic tumor emboli, used as control, positive expression was observed for Ki-67 (100%), CK7 (90%), EGFR (80%), CK20 (70%), p53 (70%), MUC5AC (70%), MUC6 (60%), MUC2 (40%), CD10 (25%), and HER2 (15%). Expression of MUC2, CK20, and the Ki-67 labeling index was significantly higher in control adenocarcinomas as compared with MPCs (P<0.05). However, there was no significant difference in other clinicopathologic features and overall patient survival. Subclassification of MPCs into 2 subgroups according to the proportion of micropapillary component (cut-off value was 20%) failed to find any significant clinicopathologic differences (P>0.05). Although MPCs in other organs show a poor prognosis, this does not seem to be true for gastric MPCs. Further larger studies are necessary to confirm our initial findings.
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-gu, Seoul, Korea.
authors.forename: Ji Hyeon
authors.initials: JH
authors.lastname: Roh
authors.forename: Amitabh
authors.initials: A
authors.lastname: Srivastava
authors.forename: Gregory Y
authors.initials: GY
authors.lastname: Lauwers
authors.forename: Jungsuk
authors.initials: J
authors.lastname: An
authors.forename: Kee-Taek
authors.initials: KT
authors.lastname: Jang
authors.forename: Cheol Keun
authors.initials: CK
authors.lastname: Park
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Sohn
authors.forename: Sung
authors.initials: S
authors.lastname: Kim
authors.forename: Kyoung-Mee
authors.initials: KM
authors.lastname: Kim
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000737:chemistry / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D000231:Adenocarcinoma, Papillary / Q000737:chemistry / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D066246:ErbB Receptors / Q000032:analysis; D005260:Female; D005752:Gastric Mucins / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D007633:Keratins / Q000032:analysis; D019394:Ki-67 Antigen / Q000032:analysis; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D056910:Republic of Korea; D013274:Stomach Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; D066246:ErbB Receptors; D005752:Gastric Mucins; D007633:Keratins; D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D016159:Tumor Suppressor Protein p53; C495901:TP53 protein, human; C512478:EGFR protein, human; C508053:ERBB2 protein, human