Thymic uptake of iodine-131 in the anterior mediastinum

Two thyroidectomized patients with a history of differentiated thyroid carcinoma are presented who had nonmetastatic mediastinal 131I uptake following therapeutic doses of 131I. Chest CT scans in both patients demonstrated an anterior mediastinal mass. Surgical excision in one patient and a percutaneous CT-guided fine needle aspiration biopsy in the other disclosed normal thymus tissue. Iodine-131 uptake in the anterior mediastinum in patients thyroidectomized for follicular or papillary thyroid carcinoma may represent the thymus.     

Selective impairment of serum antibody repertoires toward muscle and thymus antigens in patients with seronegative and seropositive myasthenia gravis

We analyzed the antibody (Ab) repertoires of IgM and IgG of patients with seropositive and patients with seronegative myasthenia gravis (MG) toward self antigens by means of a quantitative immunoblotting technique using normal human tissue extracts as sources of self antigens. Repertoires of reactivities of IgG and IgM with liver, kidney and stomach antigens were conserved between myasthenic patients and controls. IgG and IgM Ab repertoires toward muscle antigens differed significantly between patients with seropositive MG and healthy donors, as assessed by multiparametric statistical analysis. Patterns of Ab reactivities to muscle antigens were similar in patients with seronegative MG and healthy controls. Antibody repertoires of IgG and IgM toward thymus antigens of both seropositive and seronegative MG patients, differed significantly from those of healthy individuals. Our results indicate that MG is characterized by a selective impairment of self-reactive Ab repertoires toward muscle and thymus antigens. The observation that self-reactive Ab repertoires toward thymus antigens are similar in patients with seropositive and seronegative MG suggests that both forms of MG share common immunopathological features.     

Cervical thymic cysts

A review of cervical thymus cysts and a case report are presented. This benign lesion was, as in most cases previously reported, situated laterally on the neck, deep to the anterior border of the sternocleidomastoid muscle and thus simulating a common branchial cyst preoperative.y. But unlike the latter most cases of cervical thymus cysts are recognised during childhood. They are believed to develop in remmants of thymic tissue which have failed to descend from the third branchial pouch into the mediastinum in the 6th to 8th week of embryonic life.     

Ectopic intrathyroidal thymus diagnosed as a solid thyroid lesion: case report and review of the literature

The authors report a case of a 6-year-old boy in whom aberrant thymic tissue was misdiagnosed as an intrathyroidal solid lesion. The patient underwent hemithyroidectomy and did well. Because cervical ectopic thymus rarely produces symptoms, the true incidence in children is unclear. Surgeons need to consider this rare entity, not to mistake it as a thyroid neoplasm, and not to perform extensive thyroid resection.     

Ablation dynamics in laser sclerostomy Ab externo by means of pulsed lasers in the mid-infrared spectral range

BACKGROUND AND OBJECTIVE: Sclerostomy ab externo with pulsed laser systems is currently in phase II clinical trials. The authors investigated the ablation dynamics of tissue treated with pulsed laser systems in the mid-infrared range to estimate the extent of thermo-mechanical damage to the sclera and the anterior chamber. MATERIALS AND METHODS: Freshly harvested porcine eyes were used. A bare 400-micron fiber in direct contact with tissue was used for fistulization. Polarization light microscopy, fast-flash photography, as well as optical and acoustic transients were performed for analysis. RESULTS: Substantial mechanical tissue deformation and dissections were found during pulsed laser ablation. The mechanical damage range within tissue far exceeds the pure thermal damage zone. Aspheric cavitation bubbles of up to 3 mm in length penetrate the anterior chamber after perforation. The cavitation demonstrates a significantly larger time constant in tissue than in water. CONCLUSIONS: Early fistula occlusions due to iris adherences may be attributed to iris trauma caused by cavitation. In response to the findings of this study, the authors propose an automatic feedback system to control the ablation process and minimize secondary ocular tissue effects. With respect to the overall damage zones, a new continuous-wave, mid-infrared diode laser system seems to be superior to pulsed laser systems.     

Multilocular thymic cysts associated with thymoma. A case report

The association of multilocular thymic cysts (MTC) with thymoma is exceedingly rare, and the pathogenesis of this combination is controversial. We describe the case of a 42-year-old man with an anterior mediastinal mass found to contain MTC and thymoma. A multilocular cystic mass, measuring 13 x 6.5 x 2 cm, was found in the right lobe of the thymus, and contained a 4.7 x 2 cm thymoma in its center. Microscopic thymomas, lipomatously involuted remaining thymic tissue, and lymphoid follicles with germinal centers were found in the walls of MTC as well as in the left thymic lobe. Non-specific chronic inflammation was also present in the walls. In addition, microcysts, which were only found at the periphery of the thymoma and covered with epithelium, might have been formed secondarily by dilatation of the perivascular spaces and of Hassall's corpuscles. These findings suggest that a chronic inflammatory process was responsible for the early formation and enlargement of this patient's MTC, and that while the cavities of the MTC expanded to various degrees, the thymoma, which originated from one of the microscopic thymomas in the walls of MTC, increased in size, and grew to involve the remaining thymic tissue.     

Subxiphoidal videomediastinoscopy for diagnostic access to the anterior mediastinum

Access to the anterior mediastinum from the epigastric region through the retrosternal space, performed with a videomediastinoscope, is described. The method can be used to release the lower lobes of the thymus in transcervical thymectomy as well as for the diagnosis of retrosternal masses of uncertain origin on either side of the anterior mediastinum.     

Detection of Epstein-Barr virus in oral papilloma

Infantile hemangioendothelioma of the thymus is a rare disease. We describe a patient who developed a large anterior mediastinal mass, severe thrombocytopenia and massive pleural effusion at 1 month of age. Glucocorticosteroid and irradiation therapy had no effect on either the tumor size or clinical symptoms and the tumor was resected subtotally. Three months after the subtotal resection, the remaining tumor had almost disappeared and the symptoms had resolved. The patient has now been well for 1 year after surgery without evidence of recurrence. The tumor tissue was characterized by prominent vascular endothelial proliferation intermixed with a normal thymic structure, producing a picture consistent with that of an infantile hemangioendothelioma in the thymus. Immunohistochemically, the tumor cells showed positive staining for vimentin, factor VIII and CD34. The DNA stemline and proliferative activity were examined by flow cytometry, which revealed a diploid stemline with a low growth fraction. DNA content and cell cycle analyses of the tumor tissue may be useful for predicting the biological behavior of the tumor.     

Reactive thymus dysplasia following therapy for ACTH-producing tumors

Surgical or conservative treatment of ACTH-producing tumors results in acute drop of the previously excessively high cortisol levels. The following associated pathophysiological changes also occur in the organism's recovery from stress, such as trauma, operation or chemotherapy of tumors. Both cases result in a regeneration of the immune system, which might even be exalted. The corresponding radiographic feature is the "rebound" enlargement of the thymus occurring about six months after remission of hypercortisolism. Histological examination reveals benign thymus hyperplasia. Especially in cases of still unknown primary tumor the appearance of this anterior mediastinal mass can lead to misdiagnosis. We present the cases of two patients with diffuse thymic hyperplasia following surgical and medical correction of hypercortisolism. One patient suffered from classic Cushing's disease responding to transsphenoidal resection of an ACTH-secreting pituitary microadenoma. Six months later CT of the chest incidentally demonstrated an anterior mediastinal mass known as thymic hyperplasia. The second patient presented with an ectopic, still unkown source of ACTH-production. Six months after medical correction of hypercortisolism CT of the thorax showed an enlargement of the anterior mediastinum. Thymectomy was performed in order to exclude thymus carcinoid. Histological examination revealed benign thymus hyperplasia with negative immunostaining. CONCLUSION: Radiologists and clinicians should be familiar with the pathophysiological changes resulting from precipitously dropping cortisol levels in order to prevent diagnostic errors and unnecessary operations.     

The function of the musculo-venous "pump" of the foot in varicose veins

The functional state of foot musculo-venous "pump" was studied with the help of distal and retrograde phlebography. rheovasography and phlebotonometry in 148 patients with varicose disease. The authors suggested that in the base of its dysfunction lies the foot deep vein ectasis and the varicose insufficiency of communicating veins connected with them.     

High prevalence of thymic tissue in adults with human immunodeficiency virus-1 infection

The thymus in adults infected with the HIV-1 is generally thought to be inactive, both because of age-related involution and viral destruction. We have revisited the question of thymic function in adults, using chest-computed tomography (CT) to measure thymic tissue in HIV-1-seropositive (n = 99) or HIV-1-seronegative (n = 32) subjects, and correlating these results with the level of circulating CD4(+) and CD8(+) T cells that are phenotypically described as naive thymic emigrants. Abundant thymic tissue was detectable in many (47/99) HIV-1-seropositive adults, aged 20-59. Independent of age, radiographic demonstration of thymic tissue was significantly associated with both a higher CD4(+) T cell count (P = 0.02) and a higher percentage and absolute number of circulating naive (CD45RA+CD62L+) CD4(+) T cells (P < 0.04). The prevalence of an abundant thymus was especially high in younger HIV-1-seropositive adults ( 40 yr) regardless of CD4 count (P = 0.03). These studies suggest that the thymus is functional in some but not all adults with HIV-1 disease.     

Disaggregating parental depression and family stress in assessing families of children with developmental disabilities: a multisample analysis

Thymic nurse cells are defined in vitro as multicellular complexes of epithelial cells and thymocytes. Although these structures have been implicated in the intrathymic differentiation of thymocytes, little is known about the biology of this cell complex and about the occurrence of the cells in the thymus in situ. Therefore, to clarify the matter, in this review we have presented characteristics of epithelial cells capable of forming complexes with thymocytes, in light of the literature data and the experience of the authors. The structure of cells within the complexes allowed us to distinguish three types of thymic nurse cells. Three-dimensional reconstruction of the thymus and observations employing TEM and SEM demonstrated the presence of distinct types of complexes in various topographic regions of the thymus. Where possible, the functional relevance of the morphological data was analyzed.     

Anomalous thymic branch of the right common carotid artery

A previously unreported anomalous thymic artery that branched from the anterior aspect of right common carotid artery approximately 1 cm above bifurcation of the brachiocephalic artery was found during routine dissection. It traveled inferiorly through a plexus of inferior thyroid veins for 6 cm in front of the brachiocephalic artery and crossed the anterior surface of the trachea where it divided into two branches that supplied the right and left lobes of the thymus. The development and blood supply of the thymus and their clinical anatomy are reviewed.     

Cuff-impedance phlebography and 125I fibrinogen scanning versus roentgenographic phlebography for diagnosis of thrombophlebitis following hip surgery. A preliminary report

Seventy-eight limbs of forty-eight patients undergoing total hip replacement were studied by roentgenographic phlebography, cuff-impedance phlebography, and 125I fibrinogen scanning. Compared with roentgenographic phlebography, cuff-impedance phlebography detected seven of ten thrombi in the thigh but none of nine thrombi in the calf and popliteal veins, giving an over-all accuracy of 80 per cent. The 125I fibrinogen scanning technique detected none of the ten thrombi in the thigh and seven of the nine in the calf and popliteal veins, giving an over-all accuracy of 78 per cent. Combining the results of the two techniques, fourteen of the nineteen thrombi were detected. Cuff-impedance phlebography appears to be a useful method for the diagnosis of thrombi in the thigh after hip surgery.     

The less potent estrogenic effect of tamoxifen on bone in ovariectomized rats with established osteopenia

We studied 42 infertile men, who had been surgically treated with modified Palomo method, with intraoperative phlebography of single or multiple testicular veins. We evaluated the efficacy of the performed procedure as well as the presence of other ways of recoil outflow and the connections between the venous vessels of the right testis. In 42 cases surgically treated men with varicocele only in 4 cases the varicocele have been observed additionally on the right side. We are of the opinion that the intraoperative phlebography allows us to performed the proper and the most effective method of the operation of varicocele.     

Contrast medium studies of the venous system

PURPOSE: To give an overview of various diagnostic techniques and indications for phlebography in different parts of the body. METHODS: Procedures of conventional phlebography of the lower and upper extremity and cavography are described and their indications in comparison to alternative techniques are discussed. The literature is reviewed with regard to specific advantages and disadvantages of the different methods. RESULTS: Conventional phlebography with iodine contrast media is still considered to be the gold standard in many regards. The diagnosis of acute and chronic thrombotic disease, venous vascular occlusions, hemodynamic malfunctions and anatomic variants of the venous system can readily be established with contrast phlebography. DISCUSSION: Main disadvantages of contrast studies of the venous system are radiation exposure and adverse effects of contrast media. Non-invasive methods such as ultrasound and MR-phlebography are becoming more and more popular and may replace venography. Other techniques such as CT-phlebography and the use of CO2 as contrast medium are under investigation. The latter can be indicated in the case of contraindications against iodine contrast media. CONCLUSION: When choosing diagnostic methods for the venous system, their sensitivity and specificity for specific diagnoses and vascular territories have to be balanced against the risks and disadvantages.     

Arachnoid cysts associated with post-traumatic and spontaneous rupture into the subdural space

61 children were studied and treated between January 1986 and September 1993 for idiopathic varicocele. The aim of our study was to evaluate the advantages and disadvantages of the different techniques and to show the progression to a greater efficacy. The mean age at the time of therapy was 14 years, ranging from 7 to 16 years. All children presenting with pain or testicular asymmetry were treated. Four asymptomatic children were followed for 2 years before treatment. 36 children were treated by surgical ligature via the inguinal approach; 8 with a resection of the varicose veins as far as the tunica vaginalis. 14 children were treated by percutaneous sclerotherapy including 1 patient following unsuccessful classical surgical treatment. 12 children were treated by surgical inguinal ligature associated with peroperative phlebography and thrombosis. 56 children were reviewed postoperatively over a period which varied from 2 months to 4 years (5 lost to follow-up). For the 36 classical ligatures: 25 good results, but 9 hydroceles (5 out 8 varicose resections): 70% good results. 7 failures and 4 lost to follow-up. For the 14 percutaneous sclerotherapy: 4 technical failures (impossibility to catheterize the spermatic vein): 10 good results. For the 12 ligatures with peroperative phlebography and thrombosis: 11 good results and 1 lost to follow-up. All the above procedures were carried out at our out-patient clinic. The therapeutic choice will therefore have to take into consideration a procedure which produces the lowest morbidity rate and proves to be the most effective. The association of surgical ligature, phlebography and thrombosis meets these requirements.     

Susceptibility of mice and rats to human Lamblia. Experimental study with the use of a cultivation method

The effects of pregnancy on the lymphocyte populations in the mouse have been studied. Though cell numbers decreased in the thymus and increased in the lymph nodes draining the parauterine area, no significant changes were seen in the proportions of thymus derived (theta allo-antigen positive) and bone marrow derived (Fc receptor positive) lymphocytes. The humoral response to sheep erythrocytes was suppressed during both syngeneic and allogeneic pregnancies following a decline coincidental with that of thymic mitotic activity. Though the observed immunosuppression could be explained by a selective lymphocyte depletion, it appears more likely to be a nonspecific effect of the steroid milieu of pregnancy.     

A new technique applicable to pediatric laparoscopic surgery: abdominal wall 'area lifting' with subcutaneous wiring

BACKGROUND: Recently, the authors developed a unique method of laparoscopic surgery without pneumoperitoneum: "area lifting of the abdominal wall with subcutaneous wiring." METHODS: In this gasless procedure, the anterior abdominal wall is pulled upward by a pair of wires placed subcutaneously and held by thick sutures for "hanger lifting." Simultaneous lifting of a pair of subcutaneous wires across the abdomen, produces a wide, roof-shaped intraabdominal space sufficient for laparoscopic surgical procedures. The practical aspects of this gasless technique, as well as the authors' limited experience with this method in 24 children, ranging from 8 days to 15 years of age is presented. These children have had various pathologies including splenomegaly, rectal prolapse, ovarian cyst, gall stone, adrenal neuroblastoma, and abdominal wall abscess. CONCLUSIONS: Gasless laparoscopic surgery with double subcutaneous wiring is safe for children including neonates and those with respiratory compromise because all operative procedures are performed under normal abdominal pressure. Because of the highly elastic abdominal wall musculature inherent in children, this selective area lifting of abdominal wall creates a relatively larger peritoneal volume than in adults.     

Adjustable temporal suture in trabeculectomy with scleral flap

BACKGROUND AND OBJECTIVE: The long-term success of trabeculectomy depends primarily on the degree of scarring that occurs to the artificial filtration route that is created by the procedure. The most serious postoperative complication of trabeculectomy is a persistent shallow anterior chamber or a flat chamber. The objective of this study was to evaluate the effect of a suturing technique on the long-term success of trabeculectomy. PATIENTS AND METHODS: In this study, the authors analyzed a trabeculectomy technique that is based on the application of a suture of variable tightness on the scleral flap. The technique was performed on 11 patients subjected to trabeculectomy. RESULTS: The postoperative complication of shallow anterior chamber was successfully treated with further tightening of the suture for one patient. For each patient, the authors loosened the suture on the fourth postoperative day and removed it completely on the seventh or eighth postoperative day. The patients were observed postoperatively for a minimum of 1 year. During this period the intraocular pressure for each patient was within the normal limits. CONCLUSION: The authors contend that this trabeculectomy technique, in which a suture on the scleral flap can be adjusted for tightness and is later removed, contributes significantly to the treatment of a postoperative shallow anterior chamber or a flat chamber and to the long-term function of an effective filtration fistula.