Takaki Sakurai

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas: its histopathologic difference between 2 major types.

Intraductal papillary mucinous neoplasm (IPMN) is a unique pancreatic neoplasm developing in the ductal system. Two major histologic subtypes have been reported, that is the gastric type and the intestinal type. However, their histopathologic features, especially those of the gastric type, have not been fully described. To evaluate the features of these two types and refine their differences, we analyzed 80 IPMNs including 50 cases of the gastric type and 30 cases of the intestinal type with mucin immunohistochemistry. By defining a main duct-type lesion as predominantly involving the main pancreatic duct with or without branch ducts, and a branch duct-type lesion as exclusively centered on branch ducts or consisting of a collection of small cystic lesions, gastric-type IPMNs were mostly branch duct-type lesions (98%), whereas the intestinal-type IPMNs were usually main duct type (73%). The histologic grade of the intestinal type was generally higher than that of the gastric type. The intestinal type was also characterized by frequent intraluminal nodular growth, and severe atrophy and fibrosis of the surrounding parenchyma with mucous lake formation. In contrast, pyloric glandlike structures at the base of the papillae and pancreatic intraepithelial neoplasia (PanIN)-like complexes were more frequently observed in the gastric type. A significant difference was observed between the gastric type and the intestinal type with regard to all the above features (P<0.05). Seven cases (23%) of the intestinal type were associated with an invasive adenocarcinoma (6 mucinous and 1 ductal), versus only 1 case (2%) of the gastric type (invasive ductal carcinoma). All cases of both gastric and intestinal types expressed MUC5AC; however, high immunolabeling scores for MUC2 were mostly observed in the intestinal type (P<0.05). In conclusion, gastric and intestinal types of IPMNs have distinct histopathologic features and mucin profiles, suggesting that they may follow different biologic pathways.

Ghost cell odontogenic carcinoma arising in calcifying odontogenic cyst.

A case of exceptionally rare odontogenic malignant tumor, called ghost cell odontogenic carcinoma, is described. The tumor was considered to be derived from calcifying odontogenic cyst, which had been resected 5 years before. In the present resected specimen, cellular atypia, mitotic activity, Ki-67 labeling index, and p53 positivity were all increased in comparison with the initially resected specimen. This is a valuable case in which malignant transformation from calcifying odontogenic cyst to ghost cell odontogenic carcinoma was proven by the histopathologic and immunohistochemical findings. Pathologists should be aware of this rare entity.

Usefulness of diffusion-weighted imaging of breast tumors: quantitative and visual assessment

PurposeWe evaluated the usefulness of quantitative and visual assessment of diffusion-weighted imaging (DWI) of breast tumors to distinguish malignant from benign tumors.Materials and methodsThe DWI findings of 106 breast lesions (15 benign, 91 malignant) were retrospectively analyzed. The mean apparent diffusion coefficient (ADC) value for each lesion was calculated using b values of 250, 500, 750, and 1000 s/mm2 as a quantitative assessment. We visually evaluated the signal intensity of each breast lesion on the basis of a spinal signal intensity in DWI (b = 1000 s/mm2) and compared the mean ADC values using a threshold mean ADC +1.65 × standard deviation (SD) for malignant and benign breast lesions. Obviously strong signal intensity of the lesion relative to that of the spinal cord on DWI signifies malignancy.ResultsThe mean ADC value for benign lesions (1.50 ± 0.38 × 10−3 mm2/s) was significantly higher than that for malignant lesions (0.98 ± 0.19 × 10−3 mm2/s), with 94.5% sensitivity, 80% specificity, and 92.5% accuracy. Sensitivity for visual assessment was 91.5%, specificity was 33.3%, and total accuracy was 82.5%.ConclusionADC values, but not visual assessment, may be useful for differentiating benign and malignant breast tumors.

Molecular and immunohistologic analyses cannot reliably solve diagnostic variation of flat intraepithelial lesions of the urinary bladder.

We examined diagnostic variation of flat intraurothelial lesions with comparison with immunohistochemical and fluorescence in situ hybridization (FISH) analyses. Nine uropathologists diagnosed 23 biopsy samples from the urinary bladder. The samples were analyzed by immunohistochemical expression of cytokeratin 20, high-molecular-weight cytokeratin, Ki-67, p53, and p16(INK4a), and multicolor FISH using the UroVysion probe set (Vysis, Abbott, Des Plaines, IL). Diagnostic agreement for each classification and for nonneoplastic or neoplastic lesions was obtained in 8 (35%) and 16 (70%) of 23 lesions, respectively. The preference ratio of neoplasia to nonneoplasia (0.9 to 4.8) or carcinoma in situ to dysplasia (0.2 to 4.0) also varied among the pathologists. In 6 ancillary analyses, the majority of neoplastic lesions with diagnostic agreement indicated more than 2 aberrant results, whereas the majority of lesions without diagnostic agreement showed no or only 1 aberrant result. The molecular and immunohistochemical analyses can discriminate between neoplastic and nonneoplastic lesions; however, they cannot reliably solve diagnostic variation of flat intraepithelial lesions.

Gastrointestinal: Gastric mucosa-associated lymphoma presented with unique vascular features on magnified endoscopy combined with narrow-band imaging

Gastric lymphoma arising from mucosal associated lymphoid tissue (MALT) has distinct clinical and histological characteristics compared with nodal B-cell lymphoma. Magnified endoscopy (ME) combined with narrow band imaging (NBI) is widely used and the usefulness is well recognized for the diagnosis of gastritis and gastric cancer. However, there has been no report on ME combined with NBI for gastric MALT lymphoma, despite the necessity of differentiating it from gastric cancer. We report a case ofgastricMALTlymphomainwhichMEcombinedwithNBIcould detectuniquevascularfeaturesdifferentfromthoseseenincircumscribed atrophic gastritis or poorly differentiated adenocarcinoma. A 66-year-old woman underwent endoscopic screening of the upper gastrointestinal tract revealed ill-defined, brownish, superficial depressed lesion in the anterior wall of the upper gastric body (Fig. 1). ME combined with NBI system, consisting of an image processor (CV-260SL, Olympus Medical Systems, Tokyo, Japan), a light source (CLV-260SL), and a zoom endoscope (GIF-Q240Z) showed the disappearance of the surface structure and the appearance of abnormal blood vessels.Abnormal vessels were defined as new vessels that were not seen in the adjacent mucosa. They were large vessels like a tree trunk with long, bare branches that can be called as ‘tree like appearance’ (Fig. 2). Biopsy was taken from this abnormal portion and revealed hyperplasia of atypical centrocyte-like cells with small to medium-sized, ovoid nuclei and clear cytoplasm in the lamina propria mucosae and their infiltration among glandular epithelial cells, suggesting lymphoepithelial lesion. The atypical lymphocytes were immunohistochemically CD20+ ,C D10-, and CD5-. These findings were consistent with gastric MALT lymphoma. In this case report, we have shown that the tree-like appearance of the abnormal blood vessels, clearly observed by ME with NBI, could be one of the unique features suggestive of gastric MALT lymphoma. This finding could be helpful because superficial depressed type lesion potentially include circumscribed atrophic gastritis and poorly differentiated adenocarcinoma. Of note, these vascular findings are relatively easy to detect by using NBI, because NBI can present clearly defined vascular image. Therefore, our data also suggest the importance of NBI for the endoscopic evaluation of gastric MALTlymphoma.The combination of ME with NBI may also reduce the number of biopsy of gastric MALT lymphoma because it can provide precise information about the distribution of MALT lymphoma in the stomach.

A false positive for metastatic lymph nodes in the axillary region of a breast cancer patient following mastectomy

Recent advanced imaging modalities such as positron emission tomography (PET) detect malignancies using 2-[18F]-fluoro-2-deoxy-d-glucose (18-FDG) with high accuracy, and they contribute to decisions regarding diagnosis, staging, recurrence, and treatment response. Here, we report a case of false-positive metastatic lymph nodes that were diagnosed by PET/CT and ultrasonography in a 48-year-old breast cancer patient who had undergone mastectomy. The tumors, which were oval shaped and resembled lymph nodes, were detected by ultrasonography. PET/CT revealed high uptake of 18-FDG in the tumors. To investigate the proposed recurrence and to re-evaluate the biology of the recurrent tumors, a tumor was removed from the brachial plexus of the patient. Histological findings revealed it to be a schwannoma. All imaging modalities including PET/CT failed to distinguish benign tumors from metastatic lymph nodes in the brachial plexus. After resection of the schwannomas, the patient complained of a slight motor disorder of the second finger on the right hand. Hence, it is important to consider a false-positive case of lymph node metastasis in a breast cancer patient following mastectomy.

A case of gastric mucosa-associated lymphoid tissue lymphoma in which magnified endoscopy with narrow band imaging was useful in the diagnosis

Recently, we reported a case of gastric mucosa-associated lymphoid tissue (MALT) lymphoma presenting with unique vascular features. In the report, we defined the tree-like appearance (TLA) on the images of abnormal blood vessels which resembled branches from the trunk of a tree in the shiny mucosa, in which the glandular structure was lost. The 67-year-old female was diagnosed with gastric MALT lymphoma. The patient received eradication therapy for H. pylori. Conventional endoscopy revealed multiple ill-delineated brownish depressions in the stomach and cobblestone-like mucosa was observed at the greater curvature to the posterior wall of the upper gastric body 7 mo after successful eradication. Unsuccessful treatment of gastric MALT lymphoma was suspected on conventional endoscopy. Conventional endoscopic observations found focal depressions and cobblestone-like appearance, and these lesions were subsequently observed using magnified endoscopy combined with narrow band imaging to identify abnormal vessels presenting with a TLA within the lesions. Ten biopsies were taken from the area where abnormal vessels were present within these lesions. Ten biopsies were also taken from the lesions without abnormal vessels as a control. A total of 20 biopsy samples were evaluated to determine whether the diagnosis of MALT lymphoma could be obtained histologically from each sample. A positive diagnosis was obtained in 8/10 TLA (+) sites and in 2/10 TLA(-) sites. Target biopsies of the site with abnormal blood vessels can potentially improve diagnostic accuracy of gastric MALT lymphoma.

BiClamp forceps significantly shorten the operation time for breast surgery

PurposeA novel approach was introduced for breast surgery using the BiClamp, a new bipolar thermal energy device, to avoid complications and to shorten the time required for the dissection of the axillary lymph nodes.MethodsThirty-six patients with early breast cancer were assessed. The surgical parameters were compared between the procedures performed using the BiClamp technique (n = 14) and conventional surgery with suture ligation (n = 22). The parameters included the operation time, blood loss, and discharge on the first postoperative day. In addition, each of those parameters was compared between the patients with a high body mass index (BMI) (>22) and a low BMI (≤22). The sealed vessels were examined histologically and heat-associated morphological vessel wall alterations were evaluated.ResultsThe operation time was significantly shorter in the BiClamp group than in the control group (P = 0.017, 90 ± 18 vs 115 ± 33 min). In addition, the blood loss in the BiClamp group tended to be smaller than in the control group, but the difference was not significant (P = 0.54, 61 ± 47 vs 74 ± 67 g). No other parameters showed any significant differences between the two groups.ConclusionThe BiClamp thermofusion technique was safe and useful in breast surgery involving axillary dissection.

Diagnostic value of endometrium associated with papillary metaplastic changes in endometrial cytopathology.

Papillary metaplastic changes especially occur in both non‐neoplastic and neoplastic endometrium. We tried to investigate to assess the relationship between endometrial cytologic diagnosis and papillary metaplasia. The material consists of 160 cases of cytologic smears obtained by direct sampling of the endometrial cavity comprising 54 cases of normal proliferative endometrium (NPE), 36 cases of glandular and stromal breakdown (EGBD), and 70 cases of endometrial hyperplasia without atypia (EH). As for the correlation between the appearance of papillary metaplasia and cytological diagnosis, a statistical significance test was performed. The material consists of 40 cases of cytologic smears examined by direct sampling of the endometrial cavity comprising 10 cases of EGBD with papillary metaplasia, 10 cases of G1 without pappilary metaplasia, 10 cases of NPE without papillary metaplasia, and 10 cases of EH without papillary metaplasia. Using the comparison between appearance of papillary metaplasia and cytological diagnosis, a significant difference was only seen in the rate of correct diagnoses in EGBD cases. The nuclear area of papillary metaplastic cells in EGBD was 888.8, G1 was 928.7, NPE was 682.0, and EH was 722.2. Significant difference was observed between ECC cells in EGBD to NPE, between papillary metaplastic cells in EGBD to EH, between G1 to NPE, or between G1 to EH.

Extranodular background liver parenchyma of focal nodular hyperplasia: histopathological characteristics

Focal nodular hyperplasia (FNH) of the liver is considered to develop as a hyperplastic response to a preexisting vascular abnormality. From the pathogenic point of view, we studied histological alterations in the extranodular background liver tissue of FNH (FNH-bg-liver). We compared ten FNH-bg-livers with ten non-FNH cases (non-FNH-liver) and found small uniform nodule formations with ring-like siderosis in the FNH-bg-livers (4/7, 57%) but not in the non-FNH-livers. Abnormal small arteries not accompanied by portal tracts were observed in six of six FNH-bg-livers for which immunohistochemical study was available, while this was observed in only three of the ten non-FNH-livers. CD34-positive sinusoids around the portal tracts were observed in only the FNH-bg-livers (3/6, 50%). Further, two of ten FNH-bg-livers had ectopic pancreatic tissue. Ring-like siderosis, abnormal small arteries, CD34-positive sinusoids, and ectopic pancreatic tissue were characteristic in the extranodular background liver tissue in cases of FNH.