Main-duct intraductal papillary mucinous adenoma of the pancreas

<p>Abstract</p> <p>Background</p> <p>The prevalence of carcinoma in main-duct intraductal papillary mucinous neoplasm (IPMN) is high, and surgical resection is recommended for all patients with a main-duct IPMN.</p> <p>Results</p> <p>A main-duct IPMN with typical imagings including protruding lesions in the dilated main pancreatic duct was resected, but the histology was intraductal papillary mucinous adenoma of the pancreas.</p> <p>Discussion</p> <p>It has been reported that the presence of mural nodules and dilatation of MPD are significantly higher in malignant IPMNs. The presented case had protruding lesions in the dilated main pancreatic duct on endoscopic ultrasonography, but the histology was adenoma.</p> <p>Conclusion</p> <p>Preoperative distinction between benign and malignant IPMNs is difficult.</p

Early Gastric Cancer with Purely Enteroblastic Differentiation and No Conventional Adenocarcinoma Component

Gastric carcinoma with enteroblastic differentiation (GCED) is a rare variant of gastric carcinoma, and a part of GCED produces alpha-fetoprotein. GCED is characterized by cells with clear cytoplasm and a tubulopapillary and solid growth pattern resembling those in the primitive gut. GCED is typically overlaid by a conventional adenocarcinoma (CA) component, implying that CA in the mucosa differentiates into GCED during tumor invasion and proliferation. We present the case of a 73-year-old woman with a 10-mm superficial elevated lesion and a slight central depression at the anterior wall of the lower gastric body. Endoscopic submucosal dissection revealed tumor cells having clear cytoplasm and severely atypical nuclei characteristic of GCED. The growth pattern was predominantly solid and trabecular but included submucosal layer invasion and limited tubular growth. Atrophic pyloric mucosa without intestinal metaplasia surrounded the tumor. Immunohistochemically, the tumor cells were positive for AFP, GPC3, and SALL4. The present patient showed a purely enteroblastic differentiation without a CA component despite the presence of early cancer, indicating that few cases of GCED may arise de novo in the gastric mucosa. GCED is more aggressive compared with CA; therefore, pathologists should be aware that GCED without CA can appear in biopsy specimens of early cancer while making an accurate diagnosis

Genetic and immunohistochemical analyses of ciliated muconodular papillary tumors of the lung: A report of five cases

Ciliated muconodular papillary tumors are benign lesions located in the peripheral lung field. Recent studies revealed BRAF and epidermal growth factor receptor gene mutations and anaplastic lymphoma kinase gene rearrangement. Five ciliated muconodular papillary tumors were screened for the BRAF V600E and EGFR mutations via polymerase chain reaction. Immunohistochemical analysis was performed for the detection of the BRAF V600E and anaplastic lymphoma kinase proteins, as well as other markers including phosphorylated extracellular signal-regulated protein kinase. Three tumors (60%) harbored the BRAF V600E mutation. Immunohistochemical analysis confirmed this mutation in all of the tumor cell types. EGFR mutation and immunoactivity of the anaplastic lymphoma kinase protein were not detected. Phosphorylated extracellular signal-regulated protein kinase was negative both in the cytoplasm and nucleus of the BRAF V600E–positive tumors. Mucin 1, mucin 4, thyroid transcription factor 1, and cytokeratin 7 were positive, and mucin 5AC was partially positive, whereas napsin A and cytokeratin 20 were negative. Ciliated muconodular papillary tumor may originate from the terminal bronchioles, and the status of ERK activation reflects its benign behavior

Tumor development in Japanese patients with Lynch syndrome.

Lynch syndrome (LS) patients have a high risk of developing various tumors. This study aimed to clarify the characteristics of tumors developing in LS patients.This is a retrospective review of 55 LS patients treated at Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital.The median age at the diagnosis of the first malignant tumor and first LS-related tumor was 44 (range, 19-65) and 44 (range, 24-66) years, respectively. Of the 55 LS patients with developing malignant tumors, 45 (93.8%) developed an LS-related tumor as the first malignant tumor. Colorectal cancer (CRC) developed in 47 patients (85.4%), followed by endometrial cancer (n = 13, 56.5%) in females and gastric cancer (n = 10, 18.1%). In 6 gastric cancer patients, Helicobacter pylori was detected in resected specimens. Twenty-nine patients (52.7%) developed CRC and extra-colonic tumors; of these, 15 patients (48.3%) had mutations in MLH1, 10 (58.8%) in MSH2, and 4 (57.1%) in MSH6. At the age of 50, the cumulative incidence was 50.9% [95% confidence interval (CI), 36.9-63.3%] for CRC, 17.4% (95% CI, 5.2-35.6%) for endometrial cancer, and 5.5% (95% CI, 1.4-13.8%) for gastric cancer. Eight gastric cancer, one breast cancer patient, five bladder cancer patients, and one prostate cancer patient demonstrated loss of expression of the mismatch repair (MMR) protein; patients with thyroid cancer, spindle cell sarcoma, and giant cell tumors did not demonstrate this.Gastric cancer incidence was high in Japanese patients with LS and associated with H. pylori infection. MMR protein deficiency caused the development of malignant tumors in LS patients

The cumulative colorectal cancer incidence in Lynch syndrome patients by gender.

<p>The cumulative colorectal cancer incidence in Lynch syndrome patients by gender.</p

The first organ developed malignant tumor.

<p>The first organ developed malignant tumor.</p