Characterization of KRAS Mutation in Acinar and Langerhans Islet Cells of Patients With Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: KRAS mutations are frequent in pancreatic ductal adenocarcinoma, chronic pancreatitis, and mucinous neoplasms. In animal studies, KRAS mutations in acinar and Langerhans islets are associated with pancreatic intraepithelial neoplasia. Clinically, KRAS mutation is sometimes requested on cytology/biopsy specimens and negative results are helpful to rule out pancreatic ductal adenocarcinoma. This study set out to further elucidate these issues. METHODS: Surgical specimens with pancreatic ductal adenocarcinoma, premalignant lesions, and chronic pancreatitis were reviewed. Tissue microdissections on 53 such areas of 21 cases were performed followed by polymerase chain reaction and pyrosequencing. RESULTS: KRAS codon 12 mutations were detected in 100% pancreatic ductal adenocarcinomas. No KRAS codon 12 and 13 mutations were detected in benign acinar and Langerhans islets that lie adjacent to or away from the tumor. Variable mutation frequencies were seen in premalignant lesions. CONCLUSIONS: The results support such clinical practice that negative KRAS mutation helps rule out pancreatic ductal adenocarcinomas on small cytology/biopsy specimens. Negative KRAS mutations, however, cannot rule out pancreatic premalignant lesions. Additionally, the results that benign pancreas are negative for KRAS mutations complement the findings of other relevant study that KRAS mutation-associated premalignant lesions do not appear to arise from acinar cells or Langerhans islets.

Isolated Gastrointestinal Sarcoidosis Involving Multiple Gastrointestinal Sites Presenting as Chronic Diarrhea.

Sarcoidosis is a chronic and systemic disorder characterized by the formation of non-caseating granulomas. Very few cases of isolated gastrointestinal sarcoidosis have been reported, and even fewer, if any, report gastrointestinal sarcoidosis within multiple gastrointestinal sites concomitantly. We present a 42-year-old white man with chronic diarrhea and abdominal pain for more than 3 years. Mucosal biopsies revealed non-caseating microgranulomas in the stomach, throughout the small intestine, colon, and rectum. Prednisone therapy was initiated with a rapid improvement in symptoms and complete resolution of diarrhea within 3 weeks.

Gastrointestinal Kaposi's sarcoma: Case report and review of the literature.

Kaposi's sarcoma (KS) of the gastrointestinal tract is not an uncommon disease among individuals with acquired immunodeficiency syndrome (AIDS). The majority is asymptomatic, and for this reason, gastrointestinal KS (GI-KS) remains undiagnosed. With continued tumor growth, considerable variation in clinical presentation occurs including abdominal pain, nausea, vomiting, iron deficiency anemia (either chronic or frank gastrointestinal bleeding), and rarely mechanical obstruction alone or combined with bowel perforation. Endoscopy with biopsy allows for histological and immunohistochemical testing to confirm the diagnosis of GI-KS among those with clinical symptoms. In previous studies, dual treatment with highly active antiretroviral therapy and systemic chemotherapy have been associated with improved morbidity and mortality in individuals with visceral KS. Therefore, investigators have suggested performing screening endoscopies in select patients for early detection and treatment to improve outcome. In this review, we describe a 44 years old man with AIDS and cutaneous KS who presented for evaluation of postprandial abdominal pain, vomiting, and weight loss. On upper endoscopy, an extensive, infiltrative, circumferential, reddish mass involving the entire body and antrum of the stomach was seen. Histologic examination later revealed spindle cell proliferation, and confirmatory immunohistochemical testing revealed human herpes virus 8 latent nuclear antigen expression consistent with a diagnosis of gastric KS. Following this, we present a comprehensive review of literature on KS with emphasis on gastrointestinal tract involvement and management.

Early precursor of mixed endocrine-exocrine tumors of the gastrointestinal tract: histologic and molecular correlations.

BACKGROUND: Mixed endocrine-exocrine tumors display histologic features of endocrine and glandular differentiation. Unlike in collision tumors, the two components are thought to arise from a monoclonal precursor. Evidence from molecular testing supports the monoclonal theory and suggests that the exocrine component may give rise to the endocrine component but not vice versa. CASE REPORT: We report a case of an adenomatous polyp in the large intestine that had groups of endocrine cells arising from the crypt bases of the adenomatous (exocrine) epithelium. To our knowledge, ours is only the second report of an adenomatous polyp in which groups of microcarcinoid endocrine cells were recognized. The histologic findings in our case correlate with the molecular findings described in mixed endocrine-exocrine tumors. CONCLUSION: Our description may represent the primordial stage of a mixed endocrine-exocrine neoplasm.

Acute Kidney Injury due to Crescentic Glomerulonephritis in a Patient with Polycystic Kidney Disease.

Polycystic kidney disease is an inherited condition, characterized by the development of cysts in the kidney, as well as in other organs. Patients with polycystic kidney can suffer from the same causes of acute kidney injury as the general population. Nephritic syndrome is an uncommon cause of acute kidney injury in the general population and less common in patients with polycystic kidney disease. We report the second case of crescentic glomerulonephritis, causing acute kidney injury, in a patient with polycystic kidney disease.

Nasal sinus leiomyosarcoma in a patient with history of non-hereditary unilateral treated retinoblastoma.

Hereditary patients with a history of treated retinoblastoma (RB) have a greatly increased risk of a broad spectrum of secondary malignancies appearing many years later, with a high incidence in the head and neck region. Leiomyosarcomas (LMS) account for up to 58% of these tumors. LMS in the sinonasal region generally are uncommon and are associated with a locally aggressive course and have a poor prognosis. RB may occur in two forms. The hereditary form is generally bilateral but can present unilaterally with a positive family history and typically exhibits a germline mutation in the RB1 gene on chromosome 13. The non-hereditary form is usually unilateral but can show the same germline mutation in up to 10% of cases. Patients with hereditary RB have been shown to have a significantly higher cumulative risk of developing secondary malignancies than those with the non-hereditary form (28 vs. 1.44% respectively). Most reported cases of sinonasal LMS are in patients with a history of the bilateral hereditary form of treated RB. We report a case of LMS of the nasal sinus area in a 35-year-old African American male with a history of non-hereditary unilateral RB and radiation therapy. To the best of our knowledge, this is the first reported case of sinonasal LMS arising in a patient with a history of non-hereditary unilateral RB. The clinical history, radiology, and pathology are presented along with a brief discussion of the literature.

Transgenic overexpression of GLUT1 in mouse glomeruli produces renal disease resembling diabetic glomerulosclerosis.

Previous work identified an important role for hyperglycemia in diabetic nephropathy (The Diabetes Control and Complications Trial Research Group. N Engl J Med 329: 977-986, 1993; UK Prospective Diabetes Study Group. Lancet 352: 837-853, 1998), and increased glomerular GLUT1 has been implicated. However, the roles of GLUT1 and intracellular glucose have not been determined. Here, we developed transgenic GLUT1-overexpressing mice (GT1S) to characterize the roles of GLUT1 and intracellular glucose in the development of glomerular disease without diabetes. GLUT1 was overexpressed in glomerular mesangial cells (MC) of C57BL6 mice, a line relatively resistant to diabetic nephropathy. Blood pressure, blood glucose, glomerular morphometry, matrix proteins, cell signaling, transcription factors, and selected growth factors were examined. Kidneys of GT1S mice overexpressed GLUT1 in glomerular MCs and small vessels, rather than renal tubules. GT1S mice were neither diabetic nor hypertensive. Glomerular GLUT1, glucose uptake, mean capillary diameter, and mean glomerular volume were all increased in the GT1S mice. Moderately severe glomerulosclerosis (GS) was established by 26 wk of age in GT1S mice, with increased glomerular type IV collagen and fibronectin. Modest increases in glomerular basement membrane thickness and albuminuria were detected with podocyte foot processes largely preserved, in the absence of podocyte GLUT1 overexpression. Activation of glomerular PKC, along with increased transforming growth factor-beta1, VEGFR1, VEGFR2, and VEGF were all detected in glomeruli of GT1S mice, likely contributing to GS. The transcription factor NF-kappaB was also activated. Overexpression of glomerular GLUT1, mimicking the diabetic GLUT1 response, produced numerous features typical of diabetic glomerular disease, without diabetes or hypertension. This suggested GLUT1 may play an important role in the development of diabetic GS.

Variable histological and ultrasonic characteristics of restenosis after drug-eluting stents.

Bare-metal stents have undergone intense pathological and clinical examination, but histological characterization of drug-eluting stent (DES) restenosis (ISR) remains unknown. We report a series of cases (n=6) with intravascular ultrasound (IVUS) and pathological examinations over 8 months after DES deployment. Tissue samples were obtained using atherectomy devices in 5 cases and a thrombectomy catheter in 1 case. Histology revealed not only smooth muscle cell proliferation, which correlated with homogeneous hypoechoic tissue by IVUS in one case, but also demonstrated delayed healing features such as organized fibrin deposition in 3 cases (one with homogeneous echolucent tissue by IVUS), macrophage and T-lymphocyte infiltration in others. IVUS appearance of ISR components varied from echolucent to echodense images. This report suggests a variable histological and IVUS pattern of ISR after DES implantation. Further investigations are necessary to define the potentially pro-thrombotic histological features of ISR after DES implantation, and the relationship between the molecular mechanisms of thrombosis and DES restenosis.

Papillary fibroelastoma presenting as left ventricular mass.

A 38-year-old woman presented with chest pain. Two-dimensional echocardiography revealed a mobile mass in the left ventricle, attached to the posterior papillary muscle of the mitral valve without valvular involvement. The tumor was resected. Histopathology confirmed the tumor as papillary fibroelastoma. Our case highlights an atypical presentation of papillary fibroelastoma.

Fatal cholestatic liver failure associated with gemcitabine therapy.

Drug-induced hepatotoxicity accounts for more than a third of the cases of acute liver failure in the United States. In complex medical conditions, the diagnosis of drug-induced liver injury may be confounding and, specifically, the potential hepatotoxicity of chemotherapeutic agents may be easily overlooked. Two fatal cases of cholestatic hepatotoxicity have been previously reported, clearly implicating gemcitabine therapy. We report a third fatal case of cholestatic liver failure that we think is strongly linked to the use of gemcitabine. This chemotherapeutic agent is a fluorine analog with broad-spectrum antitumor activity commonly used in the treatment of breast, lung, prostate, and cervical cancer. The case we report is of a 45-year-old woman with a history of metastatic breast cancer to her spine. The patient was in remission for two years before she presented with a compensated mixed hepatitis of mild to moderate severity. Inpatient work-up found metastases to the right humerus and inferior pubic ramus, but none in the liver. Gemcitabine and carboplatin therapy was initiated for relapse of breast cancer. The patient's liver enzyme elevation diminished, but did not normalize before the start of chemotherapy. She received four courses of gemcitabine/carboplatin and subsequently presented with decompensated, severe cholestatic hepatitis. Transjugular liver biopsy displayed marked cholestasis and hepatocellular injury consistent with drug-induced hepatoxicity. Gemcitabine has been extensively studied in the oncology literature and at this time is thought to be a low-risk hepatotoxin causing hepatic adaptation and transient, reversible liver enzyme elevation, rarely leading to termination of gemcitabine therapy for solid tumors. We believe that gemcitabine therapy, particularly in the setting of preexisting liver injury or metastases to the liver, increases the relative risk of severe and potentially fatal hepatic injury possibly by idiosyncratic and dose-dependent mechanisms. We recommend careful monitoring and dose adjustment of gemcitabine in patients with abnormal liver function tests or evidence of hepatic metastases until further study clarifies this issue.

Lethal neonatal carnitine palmitoyltransferase II deficiency: an unusual presentation of a rare disorder.

A term male newborn, appropriate for gestational age, developed hypothermia, severe cardiac dysrrhythmia, and nonoliguric hyperkalemia within 24 hours of birth. Despite the prenatal identification of cystic renal dysplasia without oligohydramnios, at birth, a solitary left leg vascular hemangioma and large palpable kidneys were the only anomalies. Gradually hypotonia, lethargy, and poor feeding developed and by 20 hours of age recurrent cardiac dysrrhythmias, myocardial dysfunction, and renal insufficiency with intermittent hyperkalemia were apparent. Episodes of apnea developed on day 7 followed by respiratory failure, recurrent cardiac dysrrhythmias, and death on day 12. Eventually laboratory and autopsy findings confirmed the diagnosis of lethal neonatal carnitine palmitoyltransferase II deficiency.