Melanoma in the ampulla of Vater.

BACKGROUND: The most common tumors in the ampulla of Vater are adenocarcinomas. Although malignant melanoma usually occurs on the skin, it can also arise in the gastrointestinal and biliary tract. METHOD: We present a case of a 52-year-old, previously healthy man who presented with painless jaundice. RESULTS: Clinical examination revealed dilated intrahepatic and extrahepatic bile ducts and pancreatic duct due to the obstructive mass in the ampulla of Vater. The patient underwent pancreaticoduodenectomy and histopathological diagnosis of the resected tumor mass was malignant melanoma. Thorough clinical examination was preformed, but no other primary or metastatic site of melanoma could be found. In the next few months, the patient developed multiple liver metastases and died. CONCLUSION: An isolated amelanotic lesion in the ampulla of Vater can be a potential diagnostic pitfall, especially in patients who have had melanoma.

Squamous metaplasia of the peritoneum: report of a case.

The ability of the peritoneum to undergo metaplasia, especially to Müllerian-type epithelium has been recognized for a long time. The ability of mesothelial cells to modulate cytoskeletal filaments and shape is provided through the distinct form of subserosal cells, called multipotential subserosal cells, that have the function of replicative cells that differentiate into surface epithelium when affected by various stimuli. Rare forms of peritoneal metaplasia include squamous and cartilaginous metaplasia. This report presents a case of fully developed, mature peritoneal squamous metaplasia in an 85-year-old woman who underwent surgery because of small bowel perforation leading to diffuse peritonitis. This rare incidental finding almost always occurs in the background of chronic peritoneal irritation as a response to mesothelial injury. Squamos peritoneal metaplasia should not be interpreted as metastatic squamous cell carcinoma. The most important distinguishing criteria are the lack of nuclear atypia, mitoses, necrosis, and desmoplastic stromal response.

The interstitial expression of alpha-smooth muscle actin in glomerulonephritis is associated with renal function.

BACKGROUND: In a healthy kidney, contractile protein alpha-smooth muscle actin (ASMA) is immunohistochemically strongly expressed only in the blood vessels, while in pathological conditions it can be visualized in glomerular mesangial cells and interstitial myofibroblasts. The aim of this study was to explore the possible correlation between expression of ASMA in glomerulonephritis (GN) and indicators of renal function. MATERIAL/METHODS: We analyzed expression of ASMA in percutaneous renal biopsy of 142 adult and pediatric patients with GN and its correlation with blood pressure, serum creatinine, creatinine clearance and 24-hour urine protein at the time of biopsy. Immunoexpression of ASMA was analyzed quantitatively using computer-assisted morphometric analysis. Relative surface of ASMA expression in all glomeruli and interstitium was calculated for each patient. RESULTS: In adults and children, greater expression of ASMA in interstitium was associated with higher serum creatinine and reduced creatinine clearance. Conversely, greater ASMA expression in glomeruli was associated with normal or decreased serum creatinine in adults and increased creatinine clearance in children. In children, correlation was found between high blood pressure and ASMA expression in interstitium. CONCLUSIONS: We confirmed that interstitial expression of ASMA is associated with reduced renal function at time of biopsy. The connection of ASMA expression in glomeruli with lower serum creatinine and normal or increased creatinine clearance suggests a favorable role of this phenotypic change in glomerular filtration rate; further investigation is needed.

Her-2/neu assessment for gastric carcinoma: validation of scoring system.

BACKGROUND/AIMS: Gastric cancer is the second leading cause of cancer mortality in the world. Amplification of HER-2/neu oncogene has become an important biomarker for identifying patients who respond to HER-2 targeting therapy. A number of studies have analyzed HER-2/neu overexpression in gastric carcinoma, and the rate of HER2 positivity is variable, ranging from 6% to 35%. METHODOLOGY: In our study HER-2/neu expression was assessed on 73 samples of primary gastric cancer, using immunohistochemistry. For 19 patients preoperative biopsy samples and resected specimens were available. Additionally, internal ring study was performed to estimate intraobserver variability of IHC scoring among pathologists at our department. RESULTS: HER-2/neu overexpression was found in 10 (13.6%) of the tested samples, and it was more common in intestinal (22.5%) than the diffuse type (3.7%). Not one of the 6 analyzed mixed type tumors showed HER-2/neu expression. For the paired samples (preoperative biopsy samples and resected specimens) the concordance rate for HER-2/neu expression was 94.7%. CONCLUSIONS: According to high concordance rate in paired samples we consider it appropriate to evaluate HER2 expression on biopsy specimens, especially in unresectable cases, and to re-evaluate it on resected specimens if available, due to high heterogeneity of a gastric cancer.

Metaplastic breast carcinoma with melanocytic differentiation.

Metaplastic carcinoma of the breast is a rare heterogeneous malignancy, accounting for <1% of all invasive breast carcinomas, in which adenocarcinoma is found to coexist with an admixture of spindle, squamous, chondroid or bone-forming neoplastic cells. Metaplastic breast carcinoma composed of both epithelial and melanocytic elements is rare, and only seven cases have been reported so far. Reported herein is the case of a 38-year-old woman with a nodular mass in her left breast suspicious of malignancy, discovered during routine ultrasound examination. After histological and immunohistochemical examination of the resected tumor mass, initial diagnosis was collision tumor: ductal invasive carcinoma and metastatic melanoma. The patient underwent quadrantectomy, chemotherapy and radiotherapy. At 6 years follow up the patient was alive and healthy, without local recurrence or metastases. After revising slides and the literature, in addition to patient follow up, it was concluded that this case represents metaplastic carcinoma with melanocytic differentiation.