Hemophagocytic Lymphohistiocytosis Secondary to Unknown Underlying Hodgkin Lymphoma Presenting with a Cholestatic Pattern of Liver Injury.

Hemophagocytic lymphohistiocytosis (HLH) is an uncommon disease that often presents with nonspecific findings. A high index of suspicion is necessary to make a prompt diagnosis and prevent fatal disease. A 45-year-old man presented with fever, hypotension, abdominal pain, nausea, and vomiting. Imaging showed hepatosplenomegaly and laboratory tests revealed pancytopenia, increased ferritin, and a cholestatic pattern of injury with elevated alkaline phosphatase and total bilirubin. Due to a history of Crohn disease, systemic lupus erythematous, and rheumatoid arthritis, the patient was on immunosuppressants, including infliximab. After multiple negative cultures, persistent fever, and days of empiric broad spectrum antibiotics, our differential shifted to fever of unknown origin. A liver wedge biopsy revealed areas of sinusoidal dilatation with enlarged, activated macrophages containing erythrocytes and intracytoplasmic iron, consistent with hemophagocytosis due to HLH. The portal tracts showed mixed lymphoplasmacytic inflammation, a prominent bile ductular reaction, periportal fibrosis, and scattered large cells with occasional binucleation and prominent nucleoli. These cells stained positive for Epstein-Barr virus encoding region in situ hybridization, PAX5, CD15, and CD30, and hepatic involvement by classic Hodgkin lymphoma was diagnosed and determined to be the cause of the HLH and cholestatic pattern of injury. Simultaneously, a bone marrow biopsy showed diffuse involvement by Hodgkin lymphoma with a similar staining pattern. Aggressive treatment failed and the patient succumbed to multiorgan failure. HLH is a rare, potentially fatal disease, with nonspecific signs and symptoms, and should be considered in any patient presenting with fever and pancytopenia, especially if they are immune compromised.

In situ hybridization for the detection of hepatitis C virus RNA in human liver tissue.

In situ hybridization (ISH) enables visualization of specific nucleic acid in morphologically preserved cells and tissue sections. Detection of the HCV genomes in clinical specimens is useful for differential diagnosis, particularly between recurrent HCV infection and acute cellular rejection in transplant specimens. We optimized an ISH protocol that demonstrated sensitivity and specificity for detecting genomic and replicative form of HCV RNA in tissue biopsies. Digoxigenin (Dig)-labelled sense and anti-sense riboprobes were synthesized using a plasmid containing a fragment of the highly conserved HCV noncoding region as a template. The efficiency of the Dig-labelled riboprobes in detecting genomic and replicative-intermediate HCV RNA was analysed in 30 liver biopsies from patients infected or uninfected with HCV in a blinded study. A Huh7 cell line that stably replicates genome-length HCV RNA was developed to be used as a positive control. Negative control riboprobes were used in parallel to evaluate and control for background staining. The anti-sense probe detected HCV RNA in 20/21 specimens from HCV-infected liver tissues obtained from patients and in 0/9 samples from patients with non-HCV-related liver diseases, resulting in a sensitivity and specificity of 95% and 100%, respectively. HCV genomic RNA was variably distributed in tissue sections and was located primarily in the perinuclear regions in hepatocytes. Detection of HCV RNA by our optimized ISH protocol appears to be a sensitive and specific method when processing clinical specimens. It may also be revealing when exploring the pathophysiology of HCV infection by verifying the presence of viral genetic material within heptocytes and other cellular elements of diseased liver tissue. This methodology might also evaluate the response to antiviral therapies by demonstrating the absence or alteration of genetic material in clinical specimens from successfully treated patients.

Ventilator-associated pneumonia in patients with adult respiratory distress syndrome: CT evaluation.

PURPOSE: To determine the diagnostic accuracy of computed tomography (CT) for pneumonia in patients with adult respiratory distress syndrome (ARDS). MATERIALS AND METHODS: CT scans were obtained within 1 week of bronchoscopic sampling in 31 patients receiving mechanical ventilation for ARDS for more than 48 hours. Of 11 patients with pneumonia, five developed symptoms less than 11 days after the onset of ARDS (early ARDS). CT scans were rated for pneumonia independently by four radiologists who were unaware of the clinical diagnosis. Diagnostic accuracy was defined by means of the area under the receiver operating characteristic curve, or A2. RESULTS: Diagnostic accuracy for pneumonia was fair (A2 = 0.69 +/- 0.04 [standard error]) owing to 70% true-negative ratings (vs 59% true-positive ratings). The generalizability coefficient was good (0.79). No single CT finding was significantly different for the presence of pneumonia. Nondependent opacities predominated in 10 (91%) of 11 patients with pneumonia and 12 (60%) of 20 without pneumonia. Nondependent opacities predominated in nine (56%) of 16 patients with early ARDS and 13 (87%) of 15 with late ARDS. CONCLUSION: CT has fair diagnostic accuracy for ventilator-associated pneumonia in patients with ARDS owing primarily to identification of patients without pneumonia. No single CT sign was significantly different for pneumonia, but dependent atelectasis was more common in patients with early ARDS without pneumonia.

Pulmonary capillary hemangiomatosis: a clinicopathologic review.

Pulmonary capillary hemangiomatosis is a locally aggressive benign vascular neoplasm of the lung characterized by the presence of numerous cytologically benign thin-walled capillary-sized blood vessels proliferating diffusely through the pulmonary interstitium, in and around pulmonary vessels and airways. Pulmonary capillary hemangiomatosis is a rare disease characterized by pulmonary hypertension and a slowly progressive clinical course; it is frequently misdiagnosed clinically as primary pulmonary hypertension and veno-occlusive disease. The purpose of this review is to describe the clinical, radiologic, and histologic features of this rare form of pulmonary vascular neoplasm, which may present considerable diagnostic problems to both the clinician and the histopathologist. Fourteen cases of pulmonary capillary hemangiomatosis have been previously reported. In this review we describe the fourth case of pulmonary capillary hemangiomatosis in which the diagnosis was made antemortem, as well as the fourth to undergo lung transplantation.