The usefulness of S100P, mesothelin, fascin, prostate stem cell antigen, and 14-3-3 sigma in diagnosing pancreatic adenocarcinoma in cytological specimens obtained by endoscopic ultrasound guided fine-needle aspiration.

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of the pancreas is an efficient and minimally invasive procedure for the diagnosis and staging of pancreatic adenocarcinoma. Because of some limitations of EUS-FNA in diagnosis of well-differentiated or early stage cancers, the purpose of this study is to assess the added benefit of immunohistochemistry. We studied five proteins overexpressed in pancreatic adenocarcinoma, namely, prostate stem cell antigen, fascin, 14-3-3 sigma, mesothelin and S100P utilizing immunohistochemistry on paraffin sections from cellblocks obtained by EUS-FNA. Sixty-two cases of EUS-FNA of the pancreas that had follow-up histological and/or clinical diagnosis and sufficient material in cell blocks were included. Using histological diagnosis and/or clinical outcome as the reference standard, EUS-FNA shows the highest sensitivity (95%) and specificity (91%) and is superior to any marker in this study. Among five antibodies, S100P reveals the best diagnostic characters showing 90% of sensitivity and 67% of specificity. Fascin shows high specificity (92%) but low sensitivity (38%). Mesothelin has a moderate sensitivity (74%) and low specificity (33%), PSCA and 14-3-3 show high sensitivity but zero specificity. S100P and mesothelin were useful in nine indeterminate cases. S100P correctly predicted six of seven cancers and one of one without cancer and mesothelin correctly diagnosed five of seven cancers and one of two noncancers in this group. EUS-FNA cytomorphology is superior to any of the immunohistochemical markers used in this study. Use of S100P and mesothelin in cytologically borderline cases can increase the diagnostic accuracy in this group.

Clinical utility of postchemoradiation endoscopic brush cytology and biopsy in predicting residual esophageal adenocarcinoma.

BACKGROUND: Esophageal adenocarcinoma generally carries a poor prognosis. Treatment with combination chemoradiation (CRT) followed by esophagectomy is becoming common. A pathologic complete response is uncommon but predicts improved survival. Identifying the subset of patients with residual carcinoma has potential management implications. Post-CRT endoscopic brush cytology and biopsy may detect residual tumor; however, the accuracy and clinical value of these methods remain unclear. METHODS: Sixty-seven patients with esophageal adenocarcinoma who underwent preoperative CRT and post-CRT endoscopic brush cytology and biopsy followed by esophagectomy were identified. By using esophagectomy histology as the gold standard, the performance of cytology and biopsy was evaluated in diagnosing residual carcinoma. Two pathologists independently reviewed all false-negative and false-positive cases and resolved disagreements by consensus. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of cytology for diagnosing residual carcinoma were 26%, 95%, 92%, 35%, and 45%, respectively. For biopsy, these rates were 13%, 90%, 75%, 31%, and 36%, respectively. Sampling error accounted for false-negative diagnoses in approximately 66% of cytology analyses and 98% of biopsy analyses. Approximately 33% of false-negative cytology analyses and 1 false-negative biopsy analysis were caused by the under-recognition of tumor cells. Major diagnostic pitfalls included obscuring acute inflammation, necrosis, tumor cells that mimicked benign cells with radiation/reactive atypia, and the under recognition of mucin-containing adenocarcinoma cells. CONCLUSIONS: Brush cytology and biopsy were specific but not sensitive methods for predicting residual cancer after CRT. However, cytology was superior. The current results indicated that brush cytology can be used alone to diagnose residual esophageal carcinoma, and awareness of specific diagnostic pitfalls will help pathologists improve its accuracy.

Metastatic merkel cell carcinoma of the pancreas mimicking primary pancreatic endocrine tumor diagnosed by endoscopic ultrasound-guided fine needle aspiration cytology: a case report.

BACKGROUND: Merkel cell carcinoma (MCC) is a relatively infrequent, rapidly progressive and often fatal cutaneous malignancy exhibiting neuroendocrine differentiation. It has a penchant for local recurrence and distant metastasis to various sites, including regional lymph nodes, distant skin, lung, liver, testis and other rare organs, such as the pancreas. There are only 4 cases of MCC metastatic to the pancreas reported in the English-language literature, and they were all diagnosed by histology from pancreatic resection. CASE: A 79-year-old woman with a large pancreatic tail mass underwent endoscopic ultrasound guided fine needle aspiration (EUS-FNA). She had a history of MCC of the upper extremity with wide local excision 15 months earlier. Metastatic MCC was diagnosed based on the cytomorphology, characteristic immunohistochemical staining pattern, clinical history and comparison of the morphology with that of the primary tumor. CONCLUSION: The cytomorphology and immunohistochemical profile of this neoplasm mimicked a pancreatic endocrine tumor. We discuss the diagnostic pitfalls and differential diagnoses of the metastatic pancreatic MCC, highlighting the importance of thorough clinical history, attention to cytologic detail and corroborating immunohirtochemistry in arriving at the correct diagns. This is the first case ofa metastatic pancreatic MCC diagnosed by EUS-FNA cytology.

Umbilical cord stricture and overcoiling are common causes of fetal demise.

Although umbilical cord stricture and umbilical cord overcoiling have been established as causes of intrauterine fetal demise, relatively few studies addressed this issue, most of them being case reports. We reviewed a total of 268 fetal autopsies during a 3-year period from 1998 to 2001. One hundred thirty nine cases of fetal demise including spontaneous abortion were identified. Nineteen percent (26 of 139) were associated with umbilical cord stricture, overcoiling, or a combination of both. Stricture of the umbilical cord was defined as a decrease in diameter in relation of the remaining umbilical cord; overcoiling as 0.3 coil/cm or greater. Fetal demise most commonly occurred in the second trimester, with a mean gestation age of 21 weeks. The average maternal age was 33 years; 15% had a prior fetal demise. We found that 77% (20 of 26) of these cases had umbilical cord stricture only or with overcoiling, 23% (6 of 26) had umbilical cord overcoiling alone. Localized deficiency of Wharton's jelly and increased collagen were found in all cases with umbilical cord stricture with or without overcoiling. In patients with umbilical cord overcoiling alone, 25% had Wharton's jelly deficiency; half of them had increased collagen deposition in the umbilical cords. The placenta was reviewed for secondary thrombosis of the vessels of the chorionic plate. Thrombosis of the vessels of the chorionic plate was noted in 54% of the patients. Our study suggests that umbilical cord stricture and cord overcoiling may represent two distinct pathological entities commonly causing fetal demise. This observation reinforces the importance of a fetal autopsy with careful examination of the placenta and umbilical cord with documentation of the cord coil index.

Malignant rhabdoid tumor of the kidney in an adult: a case report and review of the literature.

Malignant rhabdoid tumor of the kidney is an uncommon renal tumor in children. The tumor has aggressive behavior and a poor prognosis and is extremely rare in adults; only 3 cases of renal rhabdoid tumors have been reported in adults. We describe here the microscopic, immunohistochemical, and electron microscopic characteristics of another case in a 38-year-old woman. This case reinforces the importance of recognizing this entity in the adult population.