Prognosis of Gastrointestinal Stromal Tumors Arising in the Stomach and Small Intestine: A Retrospective Study of 126 Cases from a Single Institution

BACKGROUND: Gastrointestinal stromal tumor (GIST) is the most common mesenchymal tumor in the gastrointestinal tract. As all GISTs have the potential for aggressive clinical behavior, the guidelines for defining the risk of aggressive behavior have been developed and they have been recently revised to precisely assess these patients' prognosis. METHODS: We analyzed 94 gastric and 32 small intestinal GISTs to compare the patients' survival with the risk stratification (original and revised). RESULTS: For gastric GISTs, 10 mitoses/50HPF was an important cutoff value for the risk of metastasis (1.3% vs 29.4%, respectively), whereas 16.7% of all the small intestinal GISTs with less than 5 mitoses/50HPF metastasized. The small intestinal GISTs showed higher frequencies of mucosal invasion and coagulation necrosis than did the gastric ones. Gastric GISTs had a significantly lower incidence of metastasis/recurrence than did the small intestinal ones in the same risk group. On multivariate analysis, the anatomic location (small intestine), the tumor size (>10 cm) and the mitotic count (>10/50HPF) were independent prognostic factors for a shorter disease-free survival for patients with GISTs. The mitotic count was more important than tumor size for both gastric and small intestinal GISTs. CONCLUSION: Small intestinal GIST is a more aggressive tumor than gastric GIST and the mitotic count is the most important prognostic factor for GISTs.

Epidermal Growth Factor Receptor Expression of Non-small Cell Carcinoma and Its Relationship with Genomic Mutation

BACKGROUND: It has recently been clarified that epidermal growth factor receptor (EGFR), which is a receptor tyrosine kinase of the erbB family, is abnormally activated in non-small cell lung carcinomas (NSCLC) and this fact is being utilized for creating targeted therapy. In this study, we aimed to identify the frequency of the EGFR expression and gene mutation in NSCLC, and to determine the correlation between them. METHODS: Immunohistochemical staining for EGFR, C-erbB-2, cytokeratin 7, p53 and thyroid transcription factor-1, and EGFR mutation analysis were performed using paraffin-embedded archival tissue from 228 cases of NSCLC; this included 112 squamous cell carcinomas and 116 adenocarcinomas. RESULTS: An EGFR expression and gene mutation occurred in 112 casees (53.5%) and 52 cases (22.8%), respectively. EGRF mutation was more frequent in the adenocarcinomas than in the squamous cell carcinomas, in non-smokers than in smokers, and in females than in males. EGFR mutation was significantly associated with an EGFR protein expression, and especially in adenocarcinomas. CONCLUSION: The EGFR expression in NSCLC was associated with EGFR mutation, and especially in adenocarcinomas. More studies are needed to prove the clinical significance of the EGFR expression for creating targeted therapy to treat NSCLC.

Reduced Expression of Claudin-7 Correlates with Invasiveness and Nuclear Grade of Breast Carcinomas

Background : Claudins are important components of the tight junctions in the intercellular barriers and cell polarity. Among them, claudin-7 is down-regulated in breast cancers compared with the normal breast epithelium. The aim of this study was to determine the expression pattern and prognostic value of claudin-7 in breast carcinomas. Methods : Claudin-7 expression was evaluated immunohistochemically in 42 cases of ductal carcinoma in situ (DCIS) and in 142 cases of invasive breast carcinoma (IBC) using a tissue microarray (TMA). Results : Claudin- 7 was strongly expressed in the normal luminal epithelial cells in the breast lobule. The level of claudin-7 expression was significantly lower or absent in 45.2% (19/42) of DCIS and 72.5% (103/142) of IBC. A loss or reduced expression of claudin-7 correlated with the invasiveness (p=0.001) of breast carcinomas and a high nuclear grade (p=0.013) in IBC. Conclusion: Claudin-7 is an important tight junction protein in the breast and a loss of expression may assist in the dissociation and invasion of tumor cells.

Uterus-Like Mass with Features of an Extrauterine Adenomyoma: A Case Report and Literature Review

Uterus-like masses, such as cavities lined by endometrium-type mucosa surrounded by bundles of smooth muscle cells, may strikingly resemble the uterus. In this report, we describe a case of a uterus-like mass with features of an extrauterine adenomyoma in a 42-year-old woman. The first uterine-like mass was documented by Cozzutto in 1981 and to date, 13 such cases have been reported. Three theories have been offered to explain their etiology: 1) the uterine/Mullerian duct fusion defect theory, which is based on a developmental abnormality occurring during the formation of the female genital tract, 2) the metaplastic theory, which is based on the fact that a uterus-like mass may arise from subperitoneal mesenchymal cells that retain the ability to duplicate Mullerian duct structures, and 3) the heterotopia theory. We consider that the metaplastic theory best fits with our observations in the present case as both glandular and stromal smooth muscle cells proliferated as a true neoplasm rather than as an anomaly.

Ectopic Hamartomatous Thymoma: A Case Report along with a Review of the Literature Concerning the Histogenesis and New Nomenclature

Ectopic hamartomatous thymoma (EHT) is a rare and distinctive benign neoplasm of the lower neck. We here report on a case of EHT arising in the suprasternal area of 47-year-old male patient. The well-circumscribed mass measured 7 x 6 x 4 cm and it predominantly had a solid gray-white cut surface. Microscopically, the tumor consisted of spindle cells, epithelial nests, and mature adipose tissue. The epithelial component was arranged in anastomosing cords, solid nests and variable-sized cysts that were lined by squamous or cuboidal epithelium. The spindle cells revealed the myoepithelial immunohistochemical phenotype. There was no obvious thymic differentiation nor was any normal thymic tissue observed in our case. We think that EHT needs to be reclassified with using different nomenclature to designate its origin and histology. Further, pathologists and clinicians should be aware of the existence of this tumor in the lower neck so as not to mistake it for high-grade sarcoma or spindle cell carcinoma.