41/78. Prenatal sonographic diagnosis of Pena-Shokeir syndrome type I, or fetal akinesia deformation sequence. We report on a familial case of Pena-Shokeir syndrome type I (fetal akinesia deformation sequence) born to healthy parents. The antenatal ultrasound diagnosis was based on hydramnios, restricted limb movements, decreased fetal chest movements, small chest, arthrogryposis, clubfoot, fixed extension of knees, fixed flexion of elbows, camptodactyly, kyphosis of thoracic spine, cryptorchidism, and small muscle bulk. Thymic hyperplasia was noted at autopsy. ( info) |
| A 12-year-old boy with massive true thymic hyperplasia presented with respiratory distress and dysphagia. The thymus weighed 245 g and demonstrated normal cortical and medullary components histologically. The findings in this case were compared with the clinical and pathologic features of seven previously published cases of massive hyperplasia and with cases of mild or "borderline" hyperplasia. By electron microscopy and immunoperoxidase techniques, myoid cell differentiation was demonstrated, the first documented example of myoid cells in thymic hyperplasia. These findings support the hypothesis that myoid cells are a normal component of thymic parenchyma. ( info) |
| Massive thymic hyperplasia (weight, greater than 100 gm) is a rare lesion in adolescents, and most of the anterior mediastinal masses are true neoplasms. We present a case of massive thymic hyperplasia, in which a 680-gm thymus was resected from a 15-year-old boy. We also present the computed tomographic scan appearance of this lesion, which differed from that previously described, and correlate the histological and radiological findings. ( info) |
44/78. gallium 67 uptake in thymic rebound. We have reported a case of localized thymic enlargement and uptake of gallium 67 in a child who had received antineoplastic chemotherapy. The enlarged thymus showed normal histology, a picture consistent with thymic rebound after nonspecific stress. This case further demonstrates the need to consider thymic rebound as a cause of gallium 67 uptake in children with neoplastic diseases. ( info) |
45/78. Mediastinal mass following chemotherapeutic treatment of Hodgkin's disease: recurrent tumor or thymic hyperplasia? hyperplasia of the thymus is a normal physiologic response in infants and children during recovery from life-threatening illness. New, recurrent, or residual mediastinal masses in children treated for malignant disease present a diagnostic dilemma. Are these masses recurrent disease or simply normal reactive thymic hyperplasia? Our experience from 1979 to 1986 includes 14 children aged 1 to 17 years (mean 7.4 years) who were identified with new or recurrent mediastinal masses during or after chemotherapeutic treatment for malignant disease (lymphoma 9, wilms tumor 2, leukemia 1, osteosarcoma 1, malignant teratoma 1). The mediastinal masses were treated by a variety of methods depending on the attending physician's preference (close observation 2, oral steroids 5, steroids and subsequent biopsy 1, open biopsy 6). Chest roentgenograms of "observation only" patients have showed stable mediastinal changes without clinical evidence of recurrent disease. patients treated with steroids showed resolution of the mediastinal masses in 48 hours to seven days, without recurrence. patients undergoing open biopsy showed only thymic hyperplasia and/or lymph nodes. We suggest a stepwise approach to evaluation of these patients. Mediastinal masses occurring during, or shortly following, chemotherapeutic treatments of malignant disease should first be treated with oral prednisone (60 mg/m2/d x 7 to 10 d). If the patient shows a complete or partial resolution, then follow-up includes frequent chest roentgenograms and/or a second course of steroids. If the mass fails to respond to steroids, or enlarges, then open biopsy through a minithoractomy will clarify the diagnosis. Follow-up of our patients is from 3 months to 7 1/2 years (mean 5 years).(ABSTRACT TRUNCATED AT 250 WORDS) ( info) |
46/78. Tumor-like massive thymic hyperplasia in childhood: a possible defect of T-cell maturation, histological and cytoenzymatic studies of three cases. Contrary to the transitory, enlarged thymic shadow commonly observed in babies, tumor-like Massive Thymic hyperplasia (MTH) is seldom encountered in infancy and even more rarely in children over 4 years. We present three cases of MTH affecting 10, 5 and 11 years old girls in whom the tremendous enlargement of the thymus (3 to 4 times the normal) led to consideration of a diagnosis of a genuine tumoral process and to either biopsy or surgical removal of the thymic mass. Optical histological examination showed a perfectly normal thymic tissue and indicated that MTH was linked with a simple and homogeneous hyperplasia of the lymphoid cells. Using the dot-like acid alpha-naphtyl acetate esterase (ANAE) as a marker of mature T cells, quantitative and comparative cytoenzymatic studies revealed a definite reduction of ANAE , mature T cells in the cortical and medullary areas in MTH (p less than or equal to 0.001). These findings suggest that MTH represents an intrathymic accumulation of immature T cells, a condition which may express a failure of cell differentiation perhaps connected with some thymic hormonal insufficiency. ( info) |
47/78. Rebound thymic hyperplasia after treatment of Cushing's syndrome. Rebound thymic hyperplasia has been described in children and young adults after recovery from stress. Similar thymic enlargement has been observed in patients after remission of Cushing's syndrome. In one patient successfully treated for ectopic adrenocorticotropic hormone (ACTH) syndrome by resection of a bronchial carcinoid with a hilar metastasis, the postoperative enlarging mediastinal mass suggested recurrent tumor. In another patient treated for an undetected ectopic ACTH source by a cortisol antagonist, the enlarging thymus could be confused with a thymic carcinoid. The typical thymic appearance on CT and the chronologic relation to declining cortisol levels should prevent such diagnostic errors. ( info) |
48/78. Thymic hyperplasia masquerading as recurrent Hodgkin's disease: case report and review of the literature. While the appearance of a mediastinal mass in a patient in remission from Hodgkin's disease frequently indicates recurrence, a number of benign processes may present in a similar manner. Tissue confirmation of relapse should be obtained prior to initiating further chemotherapy to avoid the morbidity of unnecessary treatment. We present a case of thymic hyperplasia that developed in a patient previously treated for Hodgkin's disease. Thymic hyperplasia is a poorly understood, apparently benign process that may be confused with recurrent lymphoma. Total excision of such a mass is recommended to rule out coexistent malignancy. ( info) |
49/78. An approach to mediastinal masses associated with hyperthyroidism. Benign thymic hyperplasia (BTH) is a known feature of hyperthyroidism, but is infrequently appreciated by clinicians. In most cases thymic enlargement is minimal; however, it may occasionally present as an appreciable anterior mediastinal mass. While surgical resection is a common approach to such a mass, recognition of the benign nature of BTH and its regression following treatment of hyperthyroidism would prevent a major surgical procedure. We present three cases of BTH associated with hyperthyroidism and describe our approach to this syndrome. ( info) |
50/78. Diagnostic value of plain chest roentgenogram and CT scan findings in four cases of massive thymic hyperplasia. Massive thymic hyperplasia (MTH) is rare in the pediatric age group, especially in infants. However, because of a wide variation in size and weight of the thymus, an enlarged gland is often resected because of suspicion of a neoplasm or a cyst. Some cases of thymoma resembling pulmonary acute infection occur less frequently than MTH, but if respiratory problems are accompanied by a large thymus immediate diagnosis is often necessary to differentiate between these two conditions. Four infants (14 days to 4 months of age) with MTH were recently studied, all having an acute onset of a severe respiratory distress. The infants were referred to our center with a tentative diagnosis of thymic or other intrathoracic tumors. The following case reports illustrate our diagnostic approach to evaluate patients with symptoms suggesting MTH and the response to the "steroid test". ( info) |