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.

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.

Corticosteroid rescue treatment of progressive fibroproliferation in late ARDS. Patterns of response and predictors of outcome.

Pulmonary fibroproliferation (PFP) is directly or indirectly the leading cause of death in patients with late ARDS. We previously reported our experience using intravenous corticosteroids (IVC) in 8 patients with late ARDS and now have expanded our observation to a total of 25 patients with severe fibroproliferation (mean lung injury score [LIS] 3) and progressive respiratory failure (RF). Thirteen patients had open-lung biopsy before treatment. Patients were started on IVC treatment (IVCT) an average of 15 +/- 7.5 days into mechanical ventilation (MV). Significant physiologic improvement (SPI) to IVCT was defined as a reduction in LIS of greater than 1 point or an increase in PaO2:FIO2 ratio of greater than 100. We observed three patterns of response: rapid responders (RR) had an SPI by day 7 (n = 15); delayed responders (DR) had an SPI by day 14 (n = 6); nonresponders (NR) were without SPI by day 14 (n = 4). Overall the following significant mean changes were seen within 7 days of IVCT: LIS from 3 to 2 (p = 0.001), PaO2:FIO2 from 162 to 234 (p = 0.0004), PEEP from 11 to 6.8 cm H2O (p = 0.001), chest radiograph score from 3.8 to 3.0 (p = 0.009), and VE from 16 to 13.6 L/min (p = 0.01). Development of pneumonia was related to the pattern of response. Surveillance bronchoscopy was effective in identifying pneumonia in eight afebrile patients. Nineteen of 25 (76 percent) patients survived the ICU admission. Comparisons were made between survivors (S) and nonsurvivors (NS) and among the three groups of responders. At the time ARDS developed, no physiologic or demographic variable could discriminate between S and NS. At the time of IVCT, only liver failure was more frequent in nonsurvivors (p = 0.035). Histologic findings at open-lung biopsy and pattern of physiologic response clearly predicted outcome. The presence of preserved alveolar architecture (p = 0.045), myxoid type fibrosis (p = 0.045), coexistent intraluminal bronchiolar fibrosis (p = 0.0045), and lack of arteriolar subintimal fibroproliferation (p = 0.045) separated S from NS. ICU survival rate was 86 percent in responders and 25 percent in nonresponders (p = 0.03). Only one death resulted from refractory respiratory failure.

The role of gallium-67 scintigraphy in diagnosing sources of fever in ventilated patients.

OBJECTIVE: To evaluate the diagnostic value of gallium-67 scintigraphy in febrile ventilated patients by correlating the findings of 67Ga scintigraphy to sources of fever and pulmonary density, as determined by a comprehensive protocolized diagnostic evaluation. DESIGN: Prospective observational study. PATIENTS: Thirty-two intubated patients on mechanical ventilation for > or = 3 days with fever (> or = 38.3 degrees C) and a new or progressive density on chest radiograph. Twenty patients (21 tests) had adult respiratory distress syndrome (ARDS). INTERVENTION: Diagnostic evaluation for fever included bronchoscopy with protected specimen brushing and (protected) bronchoalveolar lavage (BAL); computed tomography (CT) of sinuses; cultures of blood, urine, and central lines; and CT of the abdomen in high-risk patients. MEASUREMENTS AND RESULTS: Uptake of 67Ga was reported as either focal or diffuse pulmonary uptake and extrapulmonary uptake. The combined causes of fever were pneumonia (9), fibroproliferation of late ARDS (7), abdominal process (4), sinusitis (4), urinary tract infection (3), and others (6). Causes of the pulmonary densities were pneumonia (9), ARDS (13), atelectasis (7), congestive heart failure (3), and empyema (1). Marked and diffuse pulmonary uptake was found only in patients with ARDS; however, it was not useful in discriminating those patients with pulmonary fibroproliferation as the sole cause of fever (p = 0.167) from those with infection. 67Ga scintigraphy was inadequate for detecting pneumonia but valuable in identifying extrapulmonary sites of infection in patients with ARDS (p = 0.021). CONCLUSIONS: 67Ga scintigraphy should be considered only as an adjunct diagnostic test in the febrile, ventilated patient who has no obvious source of fever, despite a negative evaluation that includes testing for pneumonia, sinusitis, and urinary tract infection, conditions that are rarely detected by 67Ga scintigraphy.

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.

Signet-ring cell variant of invasive lobular carcinoma of the breast. A clinicopathologic study of 11 cases.

In signet-ring cell carcinoma of the breast, which was recognized in 1976 as a distinct clinicopathologic variant of lobular carcinoma, more than 20% of the malignant cells appear as signet rings formed by mucin-positive intracytoplasmic vacuoles. Several recent studies have demonstrated that the neoplasm behaves aggressively and is associated with a poor prognosis. However, the literature lacks information concerning steroid hormone receptor assays and DNA ploidy profiles, especially regarding how these tests affect a patient's prognosis. During a 5-year period (1985 to 1990), 11 (8.7%) of 126 cases of invasive lobular carcinoma met the criteria for signet-ring cell carcinoma. Ten of 11 cases were positive for estrogen and progesterone receptors; six cases showed type I and five showed type III DNA histograms. The high incidence of positive hormone receptors is significant: patients with receptor positive tumors, even those with type III DNA histograms, who were treated with tamoxifen citrate therapy after surgery had a significant increase in disease-free survival (30 months). Both the pathologist and the clinician should be aware of the prognostic influence of hormone receptor studies in the management of signet-ring cell carcinoma of the breast.

Radiologic manifestations of thoracic vascular Behçet's disease in African-American men.

Multiple pulmonary artery aneurysms associated with pulmonary artery thromboses and infarctions are uncommon and occur almost exclusively in Behçet's disease (BD). Because of the rarity of the disease outside endemic areas, sporadic cases may go unrecognized. We report two African-American men with thoracic vascular manifestations of BD. In one patient the diagnosis of BD was made solely on the basis of the characteristic intrathoracic involvement.

Aspiration and microscopy in the diagnosis of ectopic pregnancy.

OBJECTIVE: To compare Karman cannula aspiration followed by dissecting microscopy with suction curettage and permanent histology in obtaining and identifying chorionic villi. METHODS: Karman cannula aspiration was performed before standard curettage for failed intrauterine pregnancies (N=22) or possible ectopic gestation (N=24). Dissection microscopy for chorionic villi was performed on aspirates before submission for permanent histology. Sensitivity, specificity, positive and negative predictive value of each method in obtaining and identifying villi was determined. RESULTS: Overall, all methods were only moderately sensitive in detecting chorionic villi (50-76%). If failed intrauterine pregnancies were excluded, all methods had poor sensitivity (25-64%). However, if villi were detected, the positive predictive value of all methods was high (> 80%). CONCLUSIONS: Karman cannula aspiration followed by dissecting microscope examination or permanent histology may offer an alternative to traditional curettage in the diagnosis of ectopic gestations. A larger trial to validate these findings seems justified.

Placental metastasis from maternal carcinoma. A report of three cases.

Metastasis of a maternal neoplasm to the products of conception is extremely rare. Of the 54 reported cases in the world literature, only 14 (25%) showed fetal metastasis. More than 50% of the reported cases were not examined grossly or had no visually apparent tumor deposits. Malignant melanoma is the most common malignant maternal neoplasm to metastasize to the products of conception. We report three unusual maternal malignant neoplasms (one pancreatic and two breast cancer) with evidence of placental metastasis and discuss the risk factors for fetal involvement in these cases.

Toxoplasma gondii pneumonia in a pancreas transplant patient.

A 41-year-old woman had fever of 3 days' duration. She had had pancreas transplantation 2 years previously and had recently completed a course of antirejection medication. Temperature spikes occurred during treatment with broad spectrum antibiotics. No obvious cause for the fever was found. The patient's condition worsened, with development of shortness of breath, bilateral pulmonary infiltrates on chest radiographs, sepsis, and shock. Fiberoptic bronchoscopy with bronchoalveolar lavage showed the presence of Toxoplasma gondii. Pyrimethamine and clindamycin were started, and the patient improved. Toxoplasma gondii occurs in contaminated food containing oocysts or cysts. Organ transplantation and blood transfusions are other routes of transmission. Most recent cases have occurred in human immunodeficiency virus (HIV) patients with reactivation of previous infection. Serology and tissue biopsies are used for diagnosis. Treatment includes a combination of pyrimethamine and sulfadiazine or trisulfapyrimidines.

Pulmonary granular cell tumor coexisting with bronchogenic carcinoma.

Pulmonary granular cell tumors (GCTs) are uncommon and predominantly benign. The coexistence of GCTs with bronchogenic carcinoma is rare. We report three cases of GCT occurring simultaneously with a primary bronchogenic carcinoma. In one case mucoepidermoid carcinoma was seen colliding with a bronchial submucosal GCT. In another case an endobronchial GCT was seen beneath squamous cell carcinoma in situ and adjacent to invasive squamous carcinoma. In the third case a central bronchial GCT was identified concurrently with a peripheral adenocarcinoma. We suggest that the presence of a GCT should prompt adequate sampling to rule out the coexistence of bronchogenic carcinoma. Clinical awareness and complete evaluation for a malignant primary lung tumor will lead to more appropriate therapy. Ann Diagn Pathol 5:74-79, 2001.

A comparative study of ovarian and pelvic wall-infiltrating endometriosis.

STUDY OBJECTIVE: To compare the histology of ovarian endometriomas (OE) with that of pelvic wall-infiltrating endometriosis (PWIE) in an attempt to elucidate their histopathologic and clinical differences. DESIGN: Retrospective histologic study. SETTING: University-affiliated hospital. SUBJECTS: Randomly selected tissue samples of 10 cases each of OE and PWIE. Interventions. Immunoperoxidase and Masson's trichrome stains were applied to the samples to determine the presence of myofibroblasts and collagen, respectively. MEASUREMENTS AND MAIN RESULTS: All cases of OE showed changes suggestive of type 3 collagen deposition and myofibroblast proliferation. All cases of PWIE showed changes suggestive of type 1 collagen deposition and extensive smooth muscle metaplasia. The endometrial glands and stroma of OE tended to be on the inside lining of the chocolate cyst and did not freely intermix with native ovarian collagen. The lesions of PWIE, however, showed endometrial glands and stroma mixing freely with the native pelvic wall collagen. CONCLUSIONS: These findings suggest two different mechanisms for the pathogenesis of OE and PWIE and offer a rationale for using different surgical approaches to the different sites. Ovarian endometriosis is a lesion within the ovary with a response compatible with recent metastasis, whereas PWIE appears to be a metaplastic reaction.

The fibroproliferative phase of late adult respiratory distress syndrome.

Tissue response to insults is similar regardless of the tissue involved, and occurs in two sequential and interconnected steps, inflammation and fibroproliferation. Adult respiratory distress syndrome (ARDS) is a disease characterized by acute onset of diffuse and severe inflammatory reaction of the lung parenchyma with loss of compartmentalization, resulting in protein rich exudative edema. Following tissue injury, a complex pattern of responses begins to repair the lung. Ineffective repair is evident histologically with extensive pulmonary fibroproliferation and clinically with fever (without a source of infection) and inability to improve lung function. We will review recent observations indicating that an exaggerated pulmonary inflammatory response plays a key role in the progression of ARDS. We will provide a unifying pathogenetic model of ARDS, showing how the evolution from acute to chronic inflammation explains the progression of histological, laboratory, clinical, and physiological findings seen during the course of unresolving ARDS.

A feasibility study of salivary gland autograft transplantation for xerostomia.

BACKGROUND: Radiation-induced xerostomia is a frequent sequela in patients treated for cancer of the head and neck. One strategy to treat xerostomia would be to relocate portions of salivary tissue to adjacent submucosal sites that lie outside the radiation portals such as the anterior oral vestibule. It is not known whether salivary tissue transplanted as an autogenous free graft can survive, function adequately, and not produce mucoceles. METHODS: Salivary gland tissue from the parotid and submandibular glands of the Syrian hamster were transplanted into the submucosal layer of the cheek pouch. After 3 months of observation, looking at graft size, graft extrusion, ulceration, infection, and mucocele formation, the graft sites were harvested. The specimens then underwent pathologic analysis by hematoxylin and eosin staining, as well as immunohistochemical methods to determine positivity for cytokeratin, smooth muscle actin (SMA), and amylase. RESULTS: Histologic analysis of tissue harvested from Syrian hamsters grafted into the cheek pouch demonstrated intact, viable, organized salivary gland tissue. Eighty percent of the animals in the submandibular group and 63% of the animals in the parotid group had at least 1 graft with viable salivary tissue without undue complications. CONCLUSIONS: Salivary gland tissue can be transplanted successfully as free autogenous grafts in the Syrian hamster model. Further studies are needed to determine whether the grafts will subsequently become functional and whether growth can be biologically stimulated. This approach may be a useful strategy to protect salivary gland tissue in patients undergoing radiotherapy for head and neck cancer.

Spindle cell hemangioendothelioma. Report of three cases and review of the literature.

BACKGROUND: Spindle cell hemangioendothelioma lesions are uncommon, affect a wide age range in both sexes, and show a predilection for skin and subcutaneous tissue of the extremities. OBJECTIVE: To present three cases of spindle cell hemangioendothelioma and review the literature. METHODS: Three cases of spindle cell hemangioendothelioma are presented. RESULTS: Two of our cases first presented very early in life and progressed by local recurrences over many years. None of our cases showed evidence of metastases, but the lesions exhibited local aggressive and invasive behavior. Histologically, the lesions consist of alternating areas of dilated, thin walled cavernous vascular spaces and solid areas composed predominantly of spindle cells and clusters of epithelioid endothelial cells with intracytoplasmic vacuoles. That spindle cell hemangioendothelioma is a non-neoplastic lesion and not a neoplasm of borderline malignancy is suggested by the following observations from our cases: the repeated presence of organized intravascular thrombi in all cases, the early clinical presentation in two cases, and the presence of some degree of vascular malformation at the periphery of lesions. CONCLUSION: Both clinicians and pathologists should be aware of the existence of this lesion in order to diagnose and treat an affected patient correctly.

Immunohistochemical characterization of thyroid gland angiomatoid tumors.

The histogenesis of thyroid gland angiomatoid tumors, probably as a primary angiosarcoma, has been a controversy for many years. These tumors may be variants of undifferentiated (anaplastic) carcinomas. We report a thyroid gland angiomatoid carcinoma in a 61-year-old African American male. The tumor had a heterogeneous pattern with both sarcomatous and epithelioid areas. Tumor cells lined some vascular-like spaces and others had intracytoplasmic lumens containing red blood cells. The tumor cells were found to express multiple endothelial (factor VIII-related antigen, CD31, CD34, and Ulex europaeus I lectin) and epithelial (cytokeratin and epithelial membrane antigen) markers as well as thyroglobulin by immunohistochemistry. This rare presentation demonstrates the heterogeneous nature of thyroid gland angiomatoid carcinoma with both epithelial and endothelial differentiation.

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.