ASS1 Overexpression: A Hallmark of Sonic Hedgehog Hepatocellular Adenomas; Recommendations for Clinical Practice.

Until recently, 10% of hepatocellular adenomas (HCAs) remained unclassified (UHCA). Among the UHCAs, the sonic hedgehog HCA (shHCA) was defined by focal deletions that fuse the promoter of Inhibin beta E chain with GLI1. Prostaglandin D2 synthase was proposed as immunomarker. In parallel, our previous work using proteomic analysis showed that most UHCAs constitute a homogeneous subtype associated with overexpression of argininosuccinate synthase (ASS1). To clarify the use of ASS1 in the HCA classification and avoid misinterpretations of the immunohistochemical staining, the aims of this work were to study (1) the link between shHCA and ASS1 overexpression and (2) the clinical relevance of ASS1 overexpression for diagnosis. Molecular, proteomic, and immunohistochemical analyses were performed in UHCA cases of the Bordeaux series. The clinico-pathological features, including ASS1 immunohistochemical labeling, were analyzed on a large international series of 67 cases. ASS1 overexpression and the shHCA subgroup were superimposed in 15 cases studied by molecular analysis, establishing ASS1 overexpression as a hallmark of shHCA. Moreover, the ASS1 immunomarker was better than prostaglandin D2 synthase and only found positive in 7 of 22 shHCAs. Of the 67 UHCA cases, 58 (85.3%) overexpressed ASS1, four cases were ASS1 negative, and in five cases ASS1 was noncontributory. Proteomic analysis performed in the case of doubtful interpretation of ASS1 overexpression, especially on biopsies, can be a support to interpret such cases. ASS1 overexpression is a specific hallmark of shHCA known to be at high risk of bleeding. Therefore, ASS1 is an additional tool for HCA classification and clinical diagnosis.

Use of volumetric laser endomicroscopy for determining candidates for endoscopic therapy in superficial esophageal squamous cell carcinoma.

BACKGROUND: Accurate staging of superficial esophageal squamous cell cancer (ESCC) for endoscopic therapy is challenging. Optical coherence tomography (OCT) has been shown to be superior to high-resolution endoscopic ultrasound (EUS). Volumetric Laser Endomicroscopy (VLE), a second-generation OCT, has recently become commercially available. OBJECTIVE: To assess if VLE can determine which patients with superficial ESSC can undergo endoscopic therapy. METHODS: This is a multi-center retrospective study. Patients were included if (a) they had visible ESCC, (b) they underwent VLE and EUS for staging, and c) if superficial disease was suspected then endoscopic resection had to be performed to have accurate histology to compare the VLE scan to. VLE scans were then compared to the gold standard: histology for superficial disease and EUS for disease T1b and greater. RESULTS: Seventeen patients were included with the following disease: squamous intraepithelial neoplasia (4 patients), T1a disease (6 patients), T1b (2 patients), T2 disease (2 patients) and T3 disease (3 patients). VLE was able to distinguish superficial disease, defined as disease limited up to the lamina propria, from non-superficial disease in all cases. CONCLUSIONS: VLE may be able to determine which ESCC patients are candidates for endoscopic therapy. Prospective studies are needed to confirm this.

Endoscopic multiple biopsy and rapid diagnosis by in situ fixation and histopathologic processing.

BACKGROUND AND AIMS: Endoscopic forceps biopsy and fixation are laborious and prolong the procedure and anesthesia. Multiple biopsy overcomes these shortcomings with a single endoscope pass that cuts, like a needle biopsy, up to 25 biopsy samples of uniform size and depth during endoscope withdrawal. Biopsy specimens are collected in acquisition order and stored in a perforated plastic storage chamber within the perforated metal tip. The tip is cut off, immersed in fixative, and sent to pathology. A formatted log identifies each biopsy specimen by site and position. In pathology, the plastic storage cylinder, designed for processing and microtomy with biopsy specimens in situ, supports rapid diagnosis by frozen section and microwave or routine paraffin processing. METHODS: After a 10-patient Institutional Review Board safety study and US Food and Drug Administration registration, biopsies were performed in 57 patients during colonoscopy, upper GI endoscopy, and ERCP. A blinded retrospective study compared colon surveillance biopsies in 15 patients who underwent multiple biopsy with 15 patients who underwent forceps biopsies performed by anonymous physicians on the same day. Patient information was removed from slides, and forceps biopsies were oriented manually for blinding. RESULTS: Multiple biopsy specimens fixed and processed in situ were not significantly different from batched processed forceps biopsy specimens for depth, orientation, fixation, artifacts, and diagnostic information. Multiple biopsy colonic specimens were significantly (26%) smaller with better epithelial preservation than forceps specimens. Each biopsy saves 61 seconds during withdrawal. CONCLUSIONS: Single-pass multiple biopsy reduces biopsy time with less specimen damage, work, workplace risk, and soiling. Diagnostic quality is equal to forceps biopsy with better epithelial preservation, although 26% smaller. In pathology, in situ processing and microtomy reduce work and workplace risk. Grossing and manual orientation are unnecessary. Rapid diagnosis by frozen section and microwave or paraffin processing are facilitated. Multiple biopsy speeds diagnosis and improves productivity in endoscopic biopsy and histopathologic processing.

Type VI Choledochal Cyst-An Unusual Presentation of Jaundice.

Choledochal cysts involving the cystic duct are extremely rare, and are usually associated with cystic dilatations of the extrahepatic biliary tract. We describe a patient who presented with jaundice and was found to have a dilatation of the common bile duct on computed tomographic imaging, consistent with a choledochal cyst. He underwent a laparoscopic-converted-to-open cholecystectomy with excision of the choledochal cyst which was found to involve the cystic duct. Choledochal cysts involving the cystic duct are notably missing from the Todani classification. Although exceedingly rare, new cases of these types of cysts are being reported, in part due to advancement of diagnostic imaging modalities. We discuss the current classification scheme for choledochal cysts and we propose an expansion of this scheme.

Schwannoma of the cervical esophagus.

Esophageal schwannoma is a rare tumor first described in 1967 by Chaterlin and Fissore. These tumors are most commonly found incidentally or from diagnostic work up of dysphagia or dyspnea. This entity cannot be diagnosed on clinical or radiographic basis alone. Histology demonstrates palisading spindle cells, few if any mitotic figures, and a peripheral cuff of lymphoid cells. Immunohistochemically, tumor cells stain positive for S100, a characteristic marker of Schwann cells. Once diagnosed, surgical enucleation is the typical treatment method employed.

Sinusoidal obstruction syndrome (hepatic veno-occlusive disease).

Hepatic sinusoidal obstruction syndrome (SOS) is an obliterative venulitis of the terminal hepatic venules, which in its more severe forms imparts a high risk of mortality. SOS, also known as veno-occlusive disease (VOD), occurs as a result of cytoreductive therapy prior to hematopoietic stem cell transplantation (HSCT), following oxaliplatin-containing adjuvant or neoadjuvant chemotherapy for colorectal carcinoma metastatic to the liver and treated by partial hepatectomy, in patients taking pyrrolizidine alkaloid-containing herbal remedies, and in other particular settings such as the autosomal recessive condition of veno-occlusive disease with immunodeficiency (VODI). A central pathogenic event is toxic destruction of hepatic sinusoidal endothelial cells (SEC), with sloughing and downstream occlusion of terminal hepatic venules. Contributing factors are SEC glutathione depletion, nitric oxide depletion, increased intrahepatic expression of matrix metalloproteinases and vascular endothelial growth factor (VEGF), and activation of clotting factors. The clinical presentation of SOS includes jaundice, development of right upper-quadrant pain and tender hepatomegaly, ascites, and unexplained weight gain. Owing to the potentially critical condition of these patients, transjugular biopsy may be the preferred route for liver biopsy to exclude other potential causes of liver dysfunction and to establish a diagnosis of SOS. Treatment includes rigorous fluid management so as to avoid excessive fluid overload while avoiding too rapid diuresis or pericentesis, potential use of pharmaceutics such as defibrotide, coagulolytic agents, or methylprednisolone, and liver transplantation. Proposed strategies for prevention and prophylaxis include reduced-intensity conditioning radiation for HSCT, treatment with ursodeoxycholic acid, and inclusion of bevacizumab with oxaliplatin-based chemotherapeutic regimes. While significant progress has been made in understanding the pathogenesis of SOS and in mitigating against its adverse outcomes, this condition remains a serious complication of a selective group of medical treatments.

Acute cellular rejection resulting in sinusoidal obstruction syndrome and ascites postliver transplantation.

BACKGROUND: The cause of ascites formation postliver transplantation (LT) is multifactorial. Sinusoidal obstruction syndrome (SOS) is a rare cause of ascites post-LT and has been reported to occur as a sequela of acute cellular rejection (ACR). We sought to examine the histologic features of patients developing ascites in the setting of ACR. METHODS: By using the pathology database, we identified five patients with ACR who had ascites and 10 control patients with severe ACR without ascites. Features of SOS such as congestion, central venulitis, and hepatocyte necrosis were scored (zero absent, one mild, two moderate, and three severe) and perivenular fibrosis (zero absent, one mild, two fibrous septa present, three bridging fibrous septa, and four numerous septa with architectural distortion). Rejection activity index (Banff criteria) was determined. Clinical, biochemical and outcome information were obtained from chart review. RESULTS: All five ascites patient had histologic evidence of SOS. Statistical significance was noted between the ascites and control groups for perivenular fibrosis score (3.6 vs. 0.8, P=0.0004), congestion (3 vs. 1.2, P=0.000005), and central venulitis (3 vs. 1.7, P=0.002). All patients in the ascites group required re-LT or died whereas all control patients remain alive. No significant statistical difference was noted with donor age despite the mean being older in the ascites group (52.8 vs. 35.8 years). CONCLUSIONS: ACR resulting in SOS and associated with significant perivenular fibrosis, central venulitis and congestion may be the cause of ascites post-LT and may portend a poor prognosis for recovery.

Intrahepatic cholangiocarcinoma: new insights in pathology.

Cholangiocarcinomas are malignant tumors that derive from cholangiocytes of small intrahepatic bile ducts or bile ductules (intrahepatic cholangiocarcinoma; ICC), or of large hilar or extrahepatic bile ducts (extrahepatic cholangiocarcinoma; ECC). ICC and ECC differ in morphology, pathogenesis, risk factors, treatment, and prognosis. This review focuses on ICC, which is rising in incidence with the emergence of hepatitis C virus (HCV) infection as a risk factor. The authors examined 73 ICC, which were resected at The Mount Sinai Medical Center in New York City, and reviewed the literature. The tumors were categorized into classical and nonclassical ICCs based on histopathology. Classical ICCs (54.8%) were characterized by a tubular, glandular, or nested pattern of growth, were significantly associated with tumor size of more than 5 cm and the absence of underlying liver disease and/or advanced fibrosis. Nonclassical ICCs (45.2%) consisted of tumors with trabecular architecture, tumors that exhibited features of extrahepatic carcinomas, and carcinomas considered to be derived from hepatic progenitor cells, i.e., combined hepatocellular/cholangiocarcinomas and cholangiolocellular carcinomas (ductular type of ICC). They were smaller and often arose in chronic liver disease, mostly HCV infection, and/or with significant fibrosis. The role of immunohistochemistry in the diagnosis of ICC and the importance of the new American Joint Committee on Cancer Staging System for ICC are also discussed.

Cholangiolocellular carcinoma: an innocent-looking malignant liver tumor mimicking ductular reaction.

The authors present an interesting case of a 60-year-old man who underwent right hepatectomy for a diagnosis of hepatocellular carcinoma (HCC) on a background of noncirrhotic chronic hepatitis C. Pathologic examination confirmed the presence of HCC near the porta hepatis, which invaded the right portal vein branch. In addition, a well-demarcated 13.5 × 7.8 × 4.0 cm yellow and firm area upstream of the HCC was noted. This yellow area corresponded to a tumoral ductular proliferation, which cytologically was extremely bland, but invaded portal tracts and the adjacent liver parenchyma. This tumoral proliferation mimicked ductular reaction, except that it had more anastomosing structures and was associated with abundant hyalinized fibrotic stroma. Cytologically, the tumor cells had round to oval nuclei with fine chromatin, indistinct nucleoli, and scant cytoplasm. They exhibited immunohistochemical features of hepatic progenitor cells, i.e., expressing CK7, CK19, and N-CAM; and their malignancy was supported by the p53 and Ki67 immunoreactivity. The authors concluded that the patient had cholangiolocellular carcinoma with an aggressive hepatocellular carcinoma component. Cholangiolocellular carcinoma has been reported to be associated with chronic hepatitis C viral infection and to derive from hepatic progenitor cells, which explains why hepatocellular carcinoma and/or cholangiocarcinoma component may be present.

Modified Alcian blue enhances the intraoperative diagnosis of sentinel lymph node metastasis in invasive lobular carcinoma: a prospective study.

CONTEXT: The sensitivity of an intraoperative diagnosis of sentinel lymph node metastasis of invasive lobular carcinoma using conventional staining is low. OBJECTIVE: To develop a fast, modified, Alcian blue stain to decrease the intraoperative false-negative results in testing for metastatic invasive lobular carcinoma. DESIGN: Modified Alcian blue was optimized. Patients who had invasive lobular carcinoma on needle biopsy were candidates for this study. Touch preparations from every sentinel lymph node were prospectively prepared in the same manner, one stained with modified Alcian blue and one with conventional staining. These slides were independently interpreted. RESULTS: A total of 121 sentinel lymph nodes from 31 patients with invasive lobular carcinoma were studied. There were 11 patients (35.5%) who had at least one positive lymph node test result. There were a total of 18 positive lymph node results (14.9%). Although 10 sentinel lymph nodes with abnormalities were detected in 7 patients with conventional staining, modified Alcian blue detected 15 sentinel lymph node abnormalities in 10 patients. Modified Alcian blue increased the sensitivity compared with conventional staining from 63.6% to 90.9% (calculated based on the number of patients) and from 55.6% to 83.3% (calculated based on number of sentinel lymph nodes). The staining process takes approximately 11 minutes. CONCLUSIONS: Modified Alcian blue stain is a relatively rapid, cheap, highly sensitive, and specific method of detecting metastatic invasive lobular carcinoma. This method can be used in conjunction with conventional staining methods used intraoperatively.

Subungual squamous cell carcinoma of the toe: working toward a standardized therapeutic approach.

Subungual squamous cell carcinoma (SCC) is a rare malignancy with very few reported cases that occur on the toe. The etiology of these lesions is not known, and although this location is generally considered low risk for metastasis, cases of inguinal lymph node metastasis after toe amputation have been reported. Patients with subungual disease may meet criteria other than location that increase their risk for metastasis. Currently, no standardized approach to therapy for these patients has been established. In this article, we describe a patient with SCC of the right fourth toe with no clinical evidence of lymph-node metastasis. This patient underwent toe amputation and has done well for 2.5 years with no evidence of recurrence. We discuss this case of subungual SCC of the toe along with others in the literature to propose an optimal standardized approach for therapy and follow-up. In so doing, we aim to advance medical knowledge of subungual SCC and to improve patient care.

Effect of VEGF on tail artery interpositional loop (TAIL) flap: a rodent model for flap prefabrication.

The authors introduce an experimental model of flap prefabrication, the tail artery interpositional loop (TAIL) flap. In this model, an arterial segment from a rat tail is used to create an arteriovenous (A-V) fistula. This fistula is positioned beneath the abdominal skin flap to vascularize the overlying tissue, and a barrier of Silastic sheeting is placed below the fistula to prevent vascular ingrowth from the underlying bed. The efficacy of this new model was tested by investigating the effect of a single topical application of recombinant human VEGF (165). Treatment and control groups each contained 20 animals. In the control group, mean survival skin areas at 1, 2, 3, and 4 weeks were 12.5 percent, 27 percent, 35 percent, and 50 percent, respectively. In the VEGF (165)-treated group, survival rates were 14.8 percent, 37 percent, 48 percent, and 74.3 percent, respectively. Statistically significant differences were noted between the two groups at the 2-week ( p = 0.047), 3-week ( p = 0.048), and 4-week ( p = 0.023) time intervals. The authors conclude that the TAIL flap is a novel and useful animal model to study flap prefabrication.

Identification of a novel Wee1 isoform.

We have identified a novel isoform of Wee1 kinase (Wee1i), which uses Met215 of Wee1 as its initiation codon. RT-PCR, Western blot, and in situ hybridization verified wee1i expression in mammalian cells, rat brain, and rat thymus. Recombinant and partially purified Wee1i from rat thymus displayed kinase activity comparable to or higher than Wee1. The N-terminal 214 residues of Wee1 facilitate its ubiquitin-dependent degradation to trigger mitotic entry. Since Wee1i, lack of these 214 residues, it may evade this degradation and thus provide constitutive Wee1-like kinase activity to inhibit mitotic cell proliferation. Thus, Wee1i may play an important role in differentiation and in tumor suppression.

The jing and ras1 pathways are functionally related during CNS midline and tracheal development.

The Drosophila jing gene encodes a zinc finger protein required for the differentiation and survival of embryonic CNS midline and tracheal cells. We show that there is a functional relationship between jing and the Egfr pathway in the developing CNS midline and trachea. jing function is required for Egfr pathway gene expression and MAPK activity in both the CNS midline and trachea. jing over-expression effects phenocopy those of the Egfr pathway and require Egfr pathway function. Activation of the Egfr pathway in loss-of-function jing mutants partially rescues midline cell loss. Egfr pathway genes and jing show dominant genetic interactions in the trachea and CNS midline. Together, these results show that jing regulates signal transduction in developing midline and tracheal cells.