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We previously identified the major pathological changes in the respiratory and immune systems of patients who died of severe acute respiratory syndrome (SARS) but gained little information on the organ distribution of SARS‐associated coronavirus (SARS‐CoV). In the present study, we used a murine monoclonal antibody specific for SARS‐CoV nucleoprotein, and probes specific for a SARS‐CoV RNA polymerase gene fragment, for immunohistochemistry and in situ hybridization, respectively, to detect SARS‐CoV systematically in tissues from patients who died of SARS. SARS‐CoV was found in lung, trachea/bronchus, stomach, small intestine, distal convoluted renal tubule, sweat gland, parathyroid, pituitary, pancreas, adrenal gland, liver and cerebrum, but was not detected in oesophagus, spleen, lymph node, bone marrow, heart, aorta, cerebellum, thyroid, testis, ovary, uterus or muscle. These results suggest that, in addition to the respiratory system, the gastrointestinal tract and other organs with detectable SARS‐CoV may also be targets of SARS‐CoV infection. The pathological changes in these organs may be caused directly by the cytopathic effect mediated by local replication of the SARS‐CoV; or indirectly as a result of systemic responses to respiratory failure or the harmful immune response induced by viral infection. In addition to viral spread through a respiratory route, SARS‐CoV in the intestinal tract, kidney and sweat glands may be excreted via faeces, urine and sweat, thereby leading to virus transmission. This study provides important information for understanding the pathogenesis of SARS‐CoV infection and sheds light on possible virus transmission pathways. This data will be useful for designing new strategies for prevention and treatment of SARS. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

In order to investigate the clinical pathology of severe acute respiratory syndrome (SARS), the autopsies of three patients who died from SARS in Nan Fang Hospital Guangdong, China were studied retrospectively. Routine haematoxylin and eosin (H&E) staining was used to study all of the tissues from the three cases. The lung tissue specimens were studied further with Macchiavello staining, viral inclusion body staining, reticulin staining, PAS staining, immunohistochemistry, ultrathin sectioning and staining, light microscopy, and transmission electron microscopy. The first symptom was hyperpyrexia in all three cases, followed by progressive dyspnoea and lung field shadowing. The pulmonary lesions included bilateral extensive consolidation, localized haemorrhage and necrosis, desquamative pulmonary alveolitis and bronchitis, proliferation and desquamation of alveolar epithelial cells, exudation of protein and monocytes, lymphocytes and plasma cells in alveoli, hyaline membrane formation, and viral inclusion bodies in alveolar epithelial cells. There was also massive necrosis of splenic lymphoid tissue and localized necrosis in lymph nodes. Systemic vasculitis included oedema, localized fibrinoid necrosis, and infiltration of monocytes, lymphocytes, and plasma cells into vessel walls in the heart, lung, liver, kidney, adrenal gland, and the stroma of striated muscles. Thrombosis was present in small veins. Systemic toxic changes included degeneration and necrosis of the parenchyma cells in the lung, liver, kidney, heart, and adrenal gland. Electron microscopy demonstrated clusters of viral particles, consistent with coronavirus, in lung tissue. SARS is a systemic disease that injures many organs. The lungs, immune organs, and systemic small vessels are the main targets of virus attack, so that extensive consolidation of the lung, diffuse alveolar damage with hyaline membrane formation, respiratory distress, and decreased immune function are the main causes of death. Copyright © 2003 John Wiley & Sons, Ltd.

To investigate the relationship between T lymphoma invasion and metastasis 1 (Tiam1) and epithelial-mesenchymal transition (EMT) in human colorectal carcinomas.Tiam1, E-cadherin, CK, and vimentin expressions in normal colorectal epithelium, colorectal carcinomas (CRC) and CRC with lymphatic metastasis were determined by immunohistochemistry using a two-step method.Tiam1 expression was significantly higher in CRC than in normal colorectal epithelium (P0.01) in close correlation to the degree of tumor differentiation (P0.05). Higher Tiam1 expression was detected in CRC with lymphatic metastasis than in primary CRC (P0.05). The expressions of E-cadherin and CK in CRC tissues were significantly lowered in comparison with those in normal colorectal epithelium (P0.01), showing a correlation to tumor differentiation (P0.01) but not to lymphatic metastasis. Vimentin was significantly overexpressed in CRC (P0.01) and correlated to tumor differentiation (P0.01) but not to lymphatic metastasis. Tiam1 expression was inversely correlated to E-cadherin and CK, but positively to vimentin.Tiam1 is related to the metastasis of colorectal carcinoma, and may induce EMT to promote CRC metastasis.

To study the imaging features of primary bone of the lymphoma PLB on X-ray, CT and magnetic resonance imaging (MRI).The data of 8 patients (6 males and 3 females, aged 9-60 years with a median age of 26.5 years) with pathologically confirmed PLB were retrospectively reviewed. Plain radiographs were obtained in all the 8 cases, CT scans performed in 5 and MRI examinations in 7. Four patients underwent X-ray, CT and MRI, two underwent CT and MRI, and one underwent X-ray and MRI. Surgical resection was performed in 7 cases and biopsy done in 2, and routine histopathological examination and immunohistochemistry were performed for all patients.The site of PLB focus was found in the pelvic bone in 4 cases, right frontal bone in 1 case, proximal femoral bone in 1 case, occipital clivus in 2 cases, and vertebral column in 1 case. Plain X-ray revealed in 4 cases roughly normal shape of the involved bone with stippled interior bone structure destruction; the other 4 cases presented with slight or moderate bone expansion with obvious signs of osteolysis. CT scans displayed areas of different sizes of osteolytic cortical and marrow cavity destruction with large soft tissue masses around the lesion. MRI found heterogeneous iso- to hyperintense signals in the lesions in the bone and soft-tissue masses on T2-weighted images but homogeneous isointense signals on T2-weighted images. The tumors were obviously enhanced after contrast-enhanced scans on CT and MRI. Histological examination identified B-cell lymphoma in 5 cases and T-cell lymphoma in 4 cases.PBL is characterized in imaging examinations by basically normal shape of the involved bones with possible bone expansion, obvious stippled osteolytic destruction, large soft-tissue mass around the lesion and obvious enhancement after contrast-enhanced scans.

To investigate the diagnostic utility of C4.4A gene expression in discriminating a squamous cell carcinoma (SCC) from an adenocarcinoma by immunohistochemistry.Immunohistochemical staining was performed to detect the expression of C4.4A protein in 157 cases of SCC and 177 cases of adenocarcinoma of various organs.Overall, 141 of 157 cases of SCC strongly expressed C4.4A protein. In contrast, only 8 of 177 adenocarcinomas showed partial or scattered cell expression of C4.4A protein. The statistic difference between the two groups was highly significant (chi(2) = 244.93, P = 0.000), and also when the tumors were stratified according to the degree of differentiation (P = 0.000).C4.4A protein expression may serve as a valuable tumor marker in discriminating a squamous cell carcinoma from an adenocarcinoma, and therefore, may greatly facilitate the differential diagnosis of an epithelial malignancy.

To investigate the expression of CD25(+) lymphocytes in nasopharyngeal carcinoma (NPC) tissue and the influence of Epstein-Barr virus (EBV) infection on CD25 expression.Immunohistochemistry was used to detect CD25 expression in the NPC tissues and in situ hybridization employed to detect EBV infection with chronic nasopharyngitis tissue as the control sample.Significant difference was noted in the expression of CD25(+) lymphocytes between NPC and chronic inflammatory tissues. The expression was higher in undifferentiated NPC than in keratinizing squamous cell carcinoma and non-keratinizing carcinomas. The NPC tissue was all EBV-positive except for one sample, which was identified as keratinizing carcinoma, but the control samples were all negative for EBV infection, which was correlated with CD25 expression.The expression of CD25(+) lymphocytes is higher in NPC tissues and correlated to EBV infection.

To investigate the morphological features and immunophenotype of unspecified peripheral T cell lymphoma with distinct lymphoid follicular growth pattern.Three cases of peripheral T cell lymphoma with special pathohistological features were collected. Morphologic analysis and immunohistochemical staining for CD3, CD45RO, CD43, CD20, CD79a, cyclinD1, bcl-2, CD4, CD8 and S-100 were performed. PCR was used to study TCR gamma gene rearrangements.The main symptoms of all the three patients with the primary sites of cervix and lower jaw. There were intermittent fever and skin rashes in the course of the disease. Morphological study showed lymphoid follicular reactive hyperplasia, mantle zone disappear, prominent infiltration of marginal zones by medium-sized tumor cells with clear cytoplasm and significant nuclear atypia. The immunophenotypic profile confirmed that they were T cell lymphomas. TCR gamma gene rearrangements were found in all the three patients.In some unspecified peripheral T cell lymphomas, the distinct follicular growth pattern and incomplete effacement of the lymph node architecture make it necessary to differentiate them from reactive hyperplasia, marginal zone B cell lymphoma, follicular B cell lymphoma and mantle cell lymphoma.

To screen the genes that may play an important role in the carcinogenesis of nasopharyngeal carcinoma (NPC).Microdissection and cDNA genechip hybridization techniques were used to examine the differentially expressed genes in NPC tissue, the surrounding and adjacent tissues of NPC, and the nasopharyngeal inflammation tissue. The fluorescent signals on cDNA chip were scanned and the results of hybridization analyzed by image processing software.Many differentially expressed genes were identified between the three samples, including many different types of genes, such as those responsible for signal and protein transmission, oncogene and tumor suppression genes, immune-associated genes, apoptosis genes and DNA binding and transcription factor genes.The carcinogenesis of NPC involves many genes of a variety of types, suggesting its complex process.

To explore the clinicopathologic features and immunophenotype of hepatosplenic gammadeltaT-cell lymphoma.A case of hepatosplenic gammadeltaT-cell lymphoma was studied with conventional histopathological and immunohistochemical staining in combination of literature review.Diffuse hepatic and splenic enlargement was found in this case. Microscopically, the liver and spleen showed marked sinusoidal infiltration. The cells of hepatosplenic T-cell lymphoma were homogeneous, medium in size with pale cytoplasm, and the nuclear chromatin was loosely condensed with small inconspicuous nucleoli. The neoplastic cells were positive for CD45RO, CD3 and TIA-1, but negative for CD57, CD20 and CD79a.Hepatosplenic gammadeltaT-cell lymphoma is a rare form of peripheral T-cell lymphoma and has usually poor prognosis, which should be differentiated from other lymphomas or leukemia.

To investigate the clinicopathologic characteristics of severe acute respiratory syndrome (SARS).Three autopsy cases were studied retrospectively. Routine HE stain was used to study all the cases. Part of the lung tissue specimens were studied further with Macchiavello's stain, viral inclusion body stain, reticulin and PAS stains, immunohistochemistry, thin sections with staining, light microscopy and transmission electronic microscope investigation.The earliest symptom of all 3 cases was hyperpyrexia and followed by progressive dyspnea and appearance of lung field shadows in X rays findings. Pulmonary lesions included: bilateral and extensive consolidation, localized hemorrhage and necrosis, desquamative alveolitis and bronchitis, alveolar proliferation and desquamation, accumulation of protein exudates, mononuclear cells, lymphocytes, and plasma cells as well as hyaline membrane formation in alveoli and viral inclusion bodies were seen in the alveolus epithelial cells. The exudated organization tended to become glomeruloid organizing pneumonitis in a few avaoli. Lesions of the immune organs included: large patchy necrosis in the spleens and localized necrosis in the lymph nodes were seen. Bone marrow became restrained. There were lesions of systemic small vasculitis including edema of the perivascular tissue and vascular wall of the small veins with localized fibrinoid necrosis distributing in the heart, lungs, kidneys, adrenal glands and the striated muscles accompanying with mononuclear cells and lymphocytes infiltration. Thrombosis was seen in part of the small veins. In addition, there were also the systemic poisonous changes including: degeneration and necrosis of the parenchyma cells in lungs, liver, kidneys, heart and adrenals. Electronic microscopy demonstrated clusters of virus particles seen in the lung tissue.SARS is a systemic disease. Lungs, immune system and systemic small vessels are the main target organs attacked by the virus. Extensive consolidation of lungs, formation of hyaline membrane to a large extent, respiratory distress and decrease of immune function are the main causes of death.