Clinicopathological features of uterine neoplasms with perivascular epithelioid cell differentiation / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the neoplasm with perivascular epithelioid cell differentiation (PEComa) with respect to their morphologic, immunohistochemical and clinical phenotypes.</p><p><b>METHODS</b>Three PEComas were included in this study, one located at the left uterine horn, and two presented as a mass in the uterine corpus. The tumors were examined by histopathology and immunohistochemistry.</p><p><b>RESULTS</b>The lesions were composed of spindle, blunt epithelioid cells, with foci of, or scattered, cells showing adipose differentiation in two cases. The myomelanocytic differentiation was demonstrated, proving the diagnosis as PEComa. Mild nuclear atypia and focal necrosis was observed in one lesion, and the rest two showed malignant morphologic phenotypes including moderate nuclear atypia and coagulative necrosis. The mitotic and Ki67-labelling indices ranged from 0.5/10 HPF to 14/10 HPF and 0.6% to 7.0%, respectively. All of the three patients remain alive. Malignant nature of the two lesions with worrisome morphology was confirmed by occurrence of metastases after hysterectomy.</p><p><b>CONCLUSION</b>PEComa is a rare tumor, occurring preferentially in the uterus. It is regarded as a tumor with uncertain malignant potential, but a minority of them shows malignant clinical behaviors. Some pathologic parameters including large tumor size, sheet-like necrosis, marked nuclear atypia, elevated mitotic index (> or = 10/10 HPF), aberrant mitotic figure and vascular invasion may help to establish a diagnosis of malignant PEComa.</p>

Lung pathology of severe acute respiratory syndrome / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study the morphological features of the lungs obtained from autopsies of severe acute respiratory syndrome (SARS) patients.</p><p><b>METHODS</b>Bilateral lungs from 7 patients died from SARS were carefully studied grossly and microscopically. All tissues from these cases were routinely processed and carefully studied.</p><p><b>RESULTS</b>All lungs from these cases were extremely expanded and became solid. Microscopically, the edema and fibrin exudates in the alveoli was the most common findings, especially in the early phase of the disease. The hyaline membrane was almost always present in the lungs of these cases. The organization of intra-alveolar fibrin exudates along with the interstitial fibrosis led to obliteration of alveoli and consolidation of lungs. The desquamation and hyperplasia of alveolar lining cells was also apparent. Foci of haemorrhage and lobular pneumonia, even diffuse fungal infection were frequently seen in these specimens. Micro-thrombus were easily found in these lungs.</p><p><b>CONCLUSIONS</b>The lung of SARS from autopsy is characterized by edema, intra-alveolar fibrin exudates, hyaline membrane formation, organization of intra-alveolar exudates and fibrosis, which lead to the obliteration of alveoli and consolidation of lungs.</p>

Morphological study of severe acute respiratory syndrome (SARS) / 中华病理学杂志

<p><b>OBJECTIVE</b>Seven cases of autopsy from SARS patients are studied to investigate the pathogenesis and the pathologic changes of the major organs.</p><p><b>METHODS</b>Detailed gross and microscopic examination of the autopsy specimen is performed, including lung, heart, liver, kidney, spleen and lymph nodes.</p><p><b>RESULTS</b>All of the lungs are markedly enlarged and consolidated. Microscopically, pulmonary edema is a prominent finding, especially at the early stage of the disease (5 days after the onset). The alveolar spaces are filled with fibrinous exudates and lined with hyaline membrane. In 5 cases that undergo over 3 weeks of the course, the main pattern is organization of intra-alveolar deposit, along with fibroblastic proliferation in the alveolar septa, which leads to obliteration of alveolar space and pulmonary fibrosis. All of the lungs show bronchopneumonia, scattered hemorrhage, and proliferation of alveolar epithelial cells with desquamation. Microthrombi are seen in 6 cases. Fungal infection is noted in 2 cases. One of them is disseminative, involving bilateral lungs, heart, and kidney; the other one is diagnosed in hilar lymph nodes. In immune system, hilar and abdominal lymph nodes are usually congested and hemorrhagic, with depletion of lymphocytes, and accompanied with subcapsular sinus histiocytosis. One of the cases shows enlargement of abdominal lymph nodes, which have reduced number of germinal centers. Spleen exhibits atrophy of white pulps, and even lost of white pulps in some areas. The red pulp is markedly congested and hemorrhagic. In 5 cases, cardiomegale is prominent. Thrombosis (2 cases), focal myocarditis (1 case), and fungal myocarditis (1 case) are observed. In addition, liver shows massive necrosis (1 case) and nodular cirrhosis (1 case).</p><p><b>CONCLUSIONS</b>Lung is the major organ affected by SARS, demonstrated as diffuse alveolar damage. It is postulated that viral infection induces severe damage of alveolar epithelial and capillary endothelial cells, leads to pulmonary edema, intra-alveolar fibrin deposit, and hyaline membrane formation. Consequently, intra-alveolar organization and alveolar septal fibrosis causes loss of alveolar spaces, eventually, pulmonary fibrosis and atelectasis. The immune system is often affected, and presented as depletion of lymphoid tissue in lymph nodes and spleen. Secondary infection is a common complication, which should be paid close attention in the management of SARS patients.</p>