Child ; Choristoma ; Humans ; Male ; Neck ; pathology ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Thymus Gland ; pathology ; Thymus Neoplasms

Adult ; Choristoma ; Humans ; Male ; Mediastinal Cyst ; Neck ; pathology ; Thymus Gland ; pathology

Child ; Choristoma ; pathology ; Diagnosis, Differential ; Follow-Up Studies ; Humans ; Male ; Neoplasms, Glandular and Epithelial ; pathology ; Thymus Gland ; pathology ; Thymus Neoplasms ; pathology ; Thyroid Neoplasms ; pathology

Child ; Female ; Head and Neck Neoplasms ; diagnosis ; pathology ; surgery ; Humans ; Parathyroid Neoplasms ; diagnosis ; pathology ; surgery ; Thymus Gland ; pathology ; surgery ; Thymus Neoplasms ; diagnosis ; pathology ; surgery

The objective of study was to investigate the origin and to classify the subtype of N-methyl-N-nitrosourea (MNU)-induced thymic lymphomas in mice. Histopathologic, immunohistochemical and ultrastructural studies were performed to analyze the pathological features of the neoplasms. The results showed that the thymus in all cases became totally replaced by sheets of cells of the lymphoid series. All the tumors coexpressed CD3 and TdT. Transmission electron microscopic study showed the plasma membranes of malignant lymphoma cells were smooth. The nuclear profiles were usually regular, with varying percentage of convoluted nuclei. Few cell organoids were observed in cytoplasm. In conclusion, all the MNU-induced tumor classified by histopathologic, immunohistochemical and ultrastructural studies as precursor lymphoblastic lymphoma that were unquestionably related to the thymus origin and T-cell lineage.
Animals ; Female ; Lymphoma ; chemically induced ; pathology ; ultrastructure ; Male ; Methylnitrosourea ; adverse effects ; Mice ; Mice, Inbred C57BL ; Thymus Gland ; pathology ; ultrastructure ; Thymus Neoplasms ; chemically induced ; pathology ; ultrastructure

Humans ; Infant ; Lymphohistiocytosis, Hemophagocytic ; complications ; genetics ; pathology ; Male ; Thymus Gland ; abnormalities

PURPOSE: To analyse the ultrasonographic findings of normal thymus in infants and determine the pathologic findings. MATERIALS AND METHODS: Forty two infants without a history of chronic disease, tumor or steroid therapy were scanned in the axial planes with a 7.0 MHz sector transducer. Bilaterality, homogeneity, and the shape and intensity of thymic echogenicity were analysed; shapes were classified as one of three types, namely bilobate, quadrangular or triangular. The intensities of thymic echogenicity were compared with those of the liver and spleen under the same conditions (time-gain compensation, depth and gain). RESULTS: Bilaterality was seen in 36 cases, homogeneity in 35, homogeneity and bilaterality in 29, inhomogeneity and bilaterality in seven, and homogeneity and unilaterality in six. No case showed inhomogeneity and unilaterality. The shape was bilobate in 23 case, quadrangular in 13 and triangular in six, while the outer border was convex in 29 cases and straight in 13. In no case was echogenicity of the thymus greater than that of the liver or spleen. Transverse diameters were 21-47mm (mean, 37.0mm; SD, 9.4mm) and depths were 10-37.5mm (mean, 25.8mm; SD, 5.9mm). CONCLUSION: The usual findings of normal thymus in infants are bilaterality and homogeneity, convex or shaight outer border, and echointensity less than or equal to that of the liver and spleen. The possibility of thymic pathology is suggested when ultrasonography shows unilaterality, inhomogeneous echogenicity, and echogenicity greater than that of the liver and spleen.
Chronic Disease ; Compensation and Redress ; Humans ; Infant* ; Liver ; Pathology ; Spleen ; Thymus Gland* ; Transducers ; Ultrasonography

To investigate the development of the reticular network of the thymus with aging and under pathologic conditions, we performed reticulin stains on the following samples; 5 fetal thymi (22 to 33 weeks of gestational age) and 35 postnatal thymi (less than 1 month to 33 years of age). The latter included 1 hyperplastic thymus, 4 pathologically involuted thymi and 1 physiologically involuted thymus as well as 29 normal thymi. Reticulin fibers were invariably seen along the capsule and interlobular septae of all the thymi. In fetal thymi, reticulin fibers circumscribed only cortical blood vessels and Hassall's corpuscles. Postnatal thymi from the children aged less than 1 month showed discontinuous reticulin fibers along the blood vessels of the corticomedullary junction. With aging, the amount of reticulin fibers increased and formed a "fibroreticular network(FRN)" from the branching point of the interlobular septae along the corticomedullary junction. It completely circumscribed the outer medulla in fully developed thymi. In the hyperplastic thymus, the reticular network retained its original structure. Both pathologically and physiologically involuted thymi revealed irregularly collapsed reticulin fibers. These findings suggest that the reticular network of the thymus consists of FRNs as well as capsule and interlobular septae and matures with aging before involution.
Adult ; Aging/*pathology ; Child ; Child, Preschool ; Female ; Humans ; Hyperplasia ; Infant ; Infant, Newborn ; Pregnancy ; Thymus Gland/cytology/*pathology

It is sometimes difficult to assess the relevance of polyarteritis with treatment-related lesions in dog toxicity studies, as number of dogs used in a toxicity study is small and the lesions are similar to those seen in spontaneous diseases. This report is intended to establish a general profile of idiopathic canine polyarteritis in beagle dogs. Data from a total of 40 dog studies including 4-, 13- or 52- weeks studies conducted between 1990 and 2003 at Huntingdon Life Sciences, UK, were collected and analysed. There was no death by this disease and also no prominent clinical signs related to this disease. Histologically, males tended to develop polyarteritis more frequently than in females and epididymis is the most probable tissues, followed by thymus and heart. Dogs in two studies showed higher incidences of these lesions, whereas animals in the other studies did not exhibited, suggesting that genetic predilection plays an important role in this disease.
Animals ; Dog Diseases/*pathology ; Dogs ; Drug Evaluation, Preclinical ; Epididymis/pathology ; Female ; Male ; Myocardium/pathology ; Polyarteritis Nodosa/pathology/*veterinary ; Retrospective Studies ; Sex Distribution ; Thymus Gland/pathology ; Tissue Distribution

One-day-old SPF chicks were inoculated with the Cux-l strain of chicken infectious anemia virus (CIAV), and the clinical development of disease and its macroscopic and microscopic alterations in the thymus and bone marrow, were observed. Tissue sections of thymus and bone marrow were stained using the streptavidin-biotin peroxidase method and examined under light microscope for evaluation of antigenic intensities in tissues. Those findings were then compared with blood parameters and ELISA results obtained through collected sera during sacrifice procedures. We sought to determine: the localization of viral antigens in thymus and bone marrow tissues after inoculation, the correlation between antigen intensities and hematologic, serologic and histopathologic findings, definitive diagnostic criteria using histopathologic and immunoperoxidase methods, and the reliability of these methods in the diagnosis of CIAV infection. For this purpose, 83, one-day-old SPF chicks were used. The birds were divided into experimental (n = 52) and control (n = 26) groups. A virus dose of TCID50 of 100,000/ml was administered intramuscularly to every bird in the experimental group. Based on the results of this study, we have suggested that clinical examination, along with macroscopic and microscopic evaluation of the thymus and bone marrow, maybe undertaken starting from day 7 post-inoculation (PI). ELISA, might be of value, as it might give consistent results starting from day 14 PI. However, the most reliable results were obtained through examination of thymus and bone marrow sections from infected birds stained by immunoperoxidase technique, as early as day 4 PI.
Animals ; Bone Marrow/*pathology ; *Chicken anemia virus ; Chickens ; Circoviridae Infections/pathology/*veterinary ; Immunoenzyme Techniques ; Poultry Diseases/*pathology ; Specific Pathogen-Free Organisms ; Thymus Gland/*pathology