[Pulmonary epithelioid hemangioendothelioma: a clinicopathological analysis].

OBJECTIVE: To report 3 cases of pulmonary epithelioid haemangioendothelioma (PEH) and therefore to improve the understanding of this tumor. METHODS: The clinical pathological features of 3 cases of PEH were described and related literatures were reviewed. RESULTS: The etiology of this rare disease remained unknown. Symptoms were scanty and usually mild. Chest radiograph or computed tomography usually revealed multiple bilateral pulmonary nodules. Histologically, crown-like clusters of epithelioid tumor cells or spindle cells were filled in the alveoli at the periphery of the tumor nodules, while the central part of the nodules contained myxoid to hyaline matrix. Tumor cells generally lacked pleomorphism, mitotic activity and necrosis. They were immunohistochemically positive for CD(31) and CD(34). CK staining was positive in some cases. There was no effective treatment for this disease and its prognosis was unpredictable. CONCLUSIONS: PEH is a low grade malignancy and represents a distinct clinical pathological entity. It is rare and often misdiagnosed as other pulmonary diseases.

[Giant cell tumor of temporal bone and mandibular condyle: a case report].

Giant cell tumor of bone (GCTB) seldom occurs in the head or face. This article reported a case that GCTB occurred simultaneously in the temporal bone and mandibular condyle, and analyzed their clinical and pathological features.

[Infection of cytomegalovirus and herpes simplex virus and morphology of the infected spermatogenic cells in infertile men].

OBJECTIVE: To study the infection of human cytomegalovirus (HCMV) and herpes simplex virus type II (HSV-I) and the morphological characteristics of the infected spermatogenic cells in the semen of infertile men. METHODS: We washed and concentrated the spermatogenic cells obtained from 83 semen samples of infertile men, extracted DNA and then screened HCMV and HSV-II by polymerase chain reaction (PCR). Immunocytochemistry (ICC) was used to detect the expression of correlative virus antigens of the positive semen cells, and the cytology smear was employed to observe the morphological changes of the spermatogenic cells under the microscope after cytology staining. RESULTS: Of all the semen samples, 8 were HCMV positive, 4 HSV-II positive, but none were both HCMV and HSV-II positive. HCMV late antigens were positively and HCMV early antigens negatively expressed in the spermatogenic cells of the 8 HCMV positive cases. In the 4 HSV-II positive cases, 3 were positively and 1 weakly positively expressed. In the semen of the 12 positive cases were found large numbers of immature spermatogenic cells, with different manifestations of apoptosis, such as chromatin pycnosis, vacuoles, damaged nuclear membrane, and apoptotic bodies, but without virus infection-induced specific morphological alteration. Sperm concentration of the positive group was significantly lower than that of the negative (P < 0. 05). CONCLUSION: Spermatogenic cells infected by HCMV and HSV-II may cause pathologic lesions and affect spermatogenesis. Morphologically, the infected spermatogenic cells may undergo some pathologic alteration, such as apoptosis. The rate of HCMV infection is higher among infertile males with pathologic cells in the semen.

[Clinical and pathologic features of malignant myoepithelioma of salivary glands].

OBJECTIVE: To analyze the clinical features, morphology and biologic behavior of primary malignant myoepithelioma (MME) of salivary glands. METHODS: The H&E sections of 16 MME cases were reviewed. Immunohistochemical study using EnVision method for cytokeratin (CK), epithelial membrane antigen (EMA), vimentin, S-100 protein, desmin, muscle-specific actin (MSA), smooth muscle actin (SMA), Myo, proliferation cell nuclear antigen (PCNA), leukocyte common antigen (LCA) and glial fibrillary acidic protein (GFAP) was carried out. RESULTS: Of the 16 patients studied, 6 were males and 10 were females. Their ages ranged from 12 to 65 years (with an average age of 44 years). The tumor occurred predominantly in the parotid gland and minor salivary gland of the palate. Common clinical features included sudden and rapid tumor growth, superficial ulceration, bony destruction and nerve infiltration. Seven of the 16 patients developed local recurrences, while 2 patients had metastasis in the lymph nodes of submandibular or other cervical regions. Most tumors infiltrated adjacent normal salivary gland, adipose, muscular and bony tissues. The extent of local invasion however varied. Histologically, MME showed a wide range of morphologic appearance, with various combinations of clear, spindle, epithelioid or plasmacytoid cells. The tumor cells were atypical and demonstrated high mitotic activity. In this study, 9 cases were composed predominantly of clear tumor cells. Immunohistochemically the tumor cells were positive for CK, EMA, MSA, desmin and S-100 protein. CONCLUSIONS: In general, MME is a rare and low-grade malignant salivary gland tumor. It carries a low potential for lymph node or distant metastasis but relatively high tendency for local recurrences, resulting in destruction of adjacent soft and bony tissues. The biologic behavior also varies, depending on the site of involvement. Morphologic diagnosis of MME can be difficult in view of the wide spectrum of histologic changes. A definitive diagnosis however is possible with the application of immunohistochemistry.

[Sclerosing epithelioid fibrosarcoma: a clinicopathologic study of eight cases].

OBJECTIVE: To study the clinicopathologic features, immunophenotype and differential diagnosis of sclerosing epithelioid fibrosarcoma (SEF). METHODS: Eight cases of SEF were investigated by light microscopy and immunohistochemistry. RESULTS: There were five males and three females. Clinically, most patients presented as a slowly growing mass. Six tumors were located in the extremities or limb girdles, and two in the trunk. Grossly, most lesions were relatively well-circumscribed with a nodular or lobulated appearance. They ranged from 2.0 to 10.5 cm in size (mean 6 cm). On sectioning, they had a gray-whitish cut surface and were firm in consistency. Microscopically, the tumors were composed of uniformly round or polygonal epithelioid cells with clear to eosinophilic cytoplasm. The tumor cells were arranged predominantly in single strands or cords and embedded in a heavily hyalinized matrix. In some areas, nests, sheets, acini or alveolar structures were also noted. Nuclei atypia and brisk mitotic activity was not evident. The mitotic count measured less than 1 per 10 high power fields. However in two cases, focal areas exhibited increased cellularity, nuclei atypia and higher mitotic activity, resembling conventional fibrosarcoma. Immunohistochemically, the tumor cells showed diffuse and strong positivity for vimentin and focal or weak positivity for EMA. There was no expression for AE1/AE3, S-100 protein, HMB45, alpha-SMA, MSA, desmin, CD34, bcl-2, CD30 and LCA. Follow-up information in six patients revealed local recurrence in 3 cases and lung metastasis in 1 case. CONCLUSIONS: SEF is a rare variant of fibrosarcoma. Despite the relatively bland appearance and low mitotic activity, the tumor is capable of local recurrence and distant metastasis. Thus, it should be considered and treated as a low to intermediate grade sarcoma. SEF needs to be differentiated from a variety of benign or malignant tumors exhibiting epithelioid features and sclerotic stromal response.

[Pathological changes of lungs in patients with severity acute respiratory syndrome].

OBJECTIVE: To evaluate the progression in morphologic changes of lungs in SARS patients. METHODS: Four cases of SARS with lung tissue samples available (including one for ultrastructural examination) were enrolled into the study. Histochemical study for VG, Masson, reticulin, orcein, PAS, sirius red stains and immunohistochemical study for vimentin, desmin, smooth muscle actin, HHF-35, CD34, F8, collagen types I and III were also performed. RESULTS: According to the morphologic changes, lung lesions in SARS were subcategorized into 3 phases: acute exudative inflammation, fibrous proliferation and the final fibrotic stage. Two cases belonged to the acute exudative phase, in which the course was less than 20 days. The principal lesions consisted of acute alveolar exudative inflammation, hyperplasia of alveolar epithelium, necrosis, alveolar hyaline membrane formation, alveolar desquamation and focal fibroplasia. The acute exudative protein was PAS-positive. There was an increase in reticulin fiber formation. The reactive fibroblasts were highlighted by desmin and vimentin. One case belonged to the fibroproliferative stage, in which the course was around 25 days. Major lesions included proliferative interstitial pneumonia with early pulmonary fibrosis. There was also evidence of organizing pneumonia, with an increase in reticulin fiber formation, which had a glomeruloid appearance on special stain. The mesenchymal cells showed either myofibroblastic (which expressed desmin, HHF-35, smooth muscle actin and vimentin) or fibroblastic (which expressed vimentin only) differentiation. Fibroelastosis and fibroplasia was also noted. The remaining case belonged to the fibrotic stage, in which the course was around 75 days. The main features included diffuse fibrosis and honeycomb change, which were highlighted by sirius red stain. Immunohistochemistry showed mainly types I and IV collagen fibers. In all lesions, there was also an increase of number of CD68-positive macrophages. CONCLUSIONS: The morphologic progression in lungs of SARS patients is characterized by the development of increased fibrosis. The primitive mesenchymal cells, hyperplastic alveolar epithelial cells and macrophages play an important role in the pathogenesis.

[Expression and action of vascular endothelial growth factor and its receptor in a rat model of retinopathy of prematurity].

OBJECTIVE: To explore the expression of vascular endothelial growth factor (VEGF) and its receptors (flt-1 and flk-1) in the retina of retinopathy of prematurity (ROP), and its relation to the alteration of retinal blood vessels. METHODS: Eighty-six newborn Sprague-Dawley rats were randomly divided into hyperoxia and air groups, then each group was further divided into 1, 3, 7 and 14 days subgroups. The rats in hyperoxia group inhaled 75% oxygen and ROP model was thus set up. These animals were sacrificed respectively after 1, 3, 7 and 14 days, then the retinal endothelial cells were marked by CD34 to observe the change of retinal blood vessels. The expression of VEGF, flt-1 and flk-1 in the retina was measured by immunohistochemistry. RESULTS: The retinal capillary density index (RCDI) in control group increased as days went on (F = 21.589, P < 0.01, but it was the least on the 7th day in hyperoxia group, after the rats had been returned to air for 7 days, RCDI increased significantly (F = 67.885, P < 0.01); In the control group, the expression of VEGF and flk-1 was the strongest in the retina on the 7th day, the result had significant difference as compared with the 1st and 14th day (P < 0.05). The expression of VEGF and flk-1 on the 7th day in hyperoxia group was weaker than that of control group (P < 0.05). But on the 14th day in hyperoxia group, they were stronger than that of control (P < 0.05). The localization of the expression of flt-1 was changed when blood vessels altered, but there was no significant difference in expression intensity as a whole (P > 0.05). CONCLUSION: When the premature retina was exposed to hyperoxia, the expression of VEGF and flk-1 was reduced, and retinal blood vessels were also decreased; but the expression of VEGF and flk-1 was stronger in retina when premature rats were exposed to relative hypoxia, and the retinal blood vessels also increased significantly. It is concluded that VEGF and flk-1 may play important roles in the development of retinal blood vessels and its change in ROP. However, flt-1 has less effect compared with flk-1.

[Pathological and ultramicrostructural changes of tissues in a patient with severe acute respiratory syndrome].

OBJECTIVE: To study the morphological, ultramicrostructural and pathological changes of tissues from a patient with severe acute respiratory syndrome (SARS). METHODS: One autopsy case of diagnosed SARS was investigated. Lung puncture was performed immediately after the patient died, and the autopsy was done after 12 h. The specimens from lymph nodes, spleen, small intestine, colon and bone marrow were studied by immunohistochemical technique. The antibodies used included CD20, CD45RO (UCHL-1), CD4, CD8, CD68 and CD34. RESULTS: The principal lesions of the SARS case consisted of acute lobular intrastitial pneumonia, hyaloid membranes of pulmonic alveoli and hyperplasia and shedding of alveolar epithelium of. Virus-like inclusions occasionally contained cytoplasm of the alveolar epithelium, which were positive by histochemical staining. The adjacent blood-vessels were changed by hyperplasia and enlargement. The structures of lymph nodes and spleen were damaged with lymph follicles depletion and splenic nodules atrophy. The specific changes included reduction of lymphocytes and hyperplasia of histiocytes, depletion of the follicles of small intestine and colon wall, decreased hyperplasia of the bone marrow and increased number of the megakaryocyte. Meanwhile, in the immunohistochemical study, CD(20)(+) B cells were fully expressed in lymph nodes and spleen, and the CD45RO (UCHL-1)(+) T cells were scatteredly expressed. The number of CD4(+) help T cell was markedly decreased, while the number of CD8+ poisonal T cells increased, and the ratio of the former and latter was no more than 0.5. Under the electronic microscopy observation, virus-like particles with 80 - 160 nm diameter and halo or garland envelope were found in mononuclear macrophage and cytoplasm of alveolar epithelium. CONCLUSION: The specific lesions of SARS consist of lobular intrastitial pneumonia with the formation of hyaline membranes of lung, haemorrhage, necrosis, inflammation of blood vessels and the damages of extralung lymphohemopioetic system. The damages were very similar to the pathological features of tissues infected by human immunodeficiency virus, in which numbers of T cells decreased and CD(4)(+) T cell/CD(8)(+) T cell ratio was no more than 0.5. According to the virus-like particles found in lung of the SARS case, it is considered that these virus-like particles may be a new kind of coronavirus which caused the "atypical pneumonia".

[Effects of Helicobacter pylori infection on porcine gastric epithelial cell proliferation].

OBJECTIVE: To investigate the association between porcine gastric epithelial cell proliferation and Helicobacter pylori (Hp) infection. METHOD: Animal models of gastritis associated with Hp infection were established using "Chinese No.1 pigs". The expressions of proliferating cell nuclear antigen (PCNA) and DNA polyploid content in porcine gastric epithelial cells were quantitatively assayed by means of immunohistochemistry and Feulgen stain respectively. RESULTS: The values of PCNA labeling index (LI) in the porcine gastric epithelial cells of the experimental group were significantly higher than those of the control group (40.95+/-3.60 vs 29.4+/-12.82, P<0.01). The DNA diploid or approximate diploid content in the gastric mucosa of the pigs was significantly lower (70.78% vs 90.65%, P<0.01), but the proliferation polyploid and non-doubleploid of DNA significantly higher in the experimental group than in the control group (P<0.01). CONCLUSION: Hp infection may play a role to enhance the proliferation of gastric epithelial cells in pigs.