Ectopic thymic hyperplasia in a patient treated for Burkitt lymphoma

Thymic hyperplasia results from thymic regrowth after atrophy during stressful conditions such as burns, surgery, infection, and chemotherapy. Although thymic lesions are relatively common causes of anterior mediastinal masses, they also can develop in other mediastinal compartments on rare occasions. It is well known that thymic tissue can develop in ectopic intrathoracic lesions. Few cases of ectopic thymus associated with disturbance during thymus embryogenesis have been reported as incidental findings. We report the case of a 4-year-old boy with true thymic hyperplasia from an ectopic thymus after successful treatment for Burkitt lymphoma. This is a rare finding in the differential diagnosis of a middle mediastinal mass in a child following chemotherapy for lymphoma. The diagnosis of thymic hyperplasia from an ectopic thymus can be confirmed only histologically.     

Differentiation between rebound thymic hyperplasia and thymic relapse after chemotherapy in pediatric Hodgkin lymphoma

Background

Rebound thymic hyperplasia (RTH) is a common phenomenon caused by stress factors such as chemotherapy (CTX) or radiotherapy, with an incidence between 44% and 67.7% in pediatric lymphoma. Misinterpretation of RTH and thymic lymphoma relapse (LR) may lead to unnecessary diagnostic procedures including invasive biopsies or treatment intensification. The aim of this study was to identify parameters that differentiate between RTH and thymic LR in the anterior mediastinum.

Methods

After completion of CTX, we analyzed computed tomographies (CTs) and magnetic resonance images (MRIs) of 291 patients with classical Hodgkin lymphoma (CHL) and adequate imaging available from the European Network for Pediatric Hodgkin lymphoma C1 trial. In all patients with biopsy-proven LR, an additional fluorodeoxyglucose (FDG)-positron emission tomography (PET)-CT was assessed. Structure and morphologic configuration in addition to calcifications and presence of multiple masses in the thymic region and signs of extrathymic LR were evaluated.

Results

After CTX, a significant volume increase of new or growing masses in the thymic space occurred in 133 of 291 patients. Without biopsy, only 98 patients could be identified as RTH or LR. No single finding related to thymic regrowth allowed differentiation between RTH and LR. However, the vast majority of cases with thymic LR presented with additional increasing tumor masses (33/34). All RTH patients (64/64) presented with isolated thymic growth.

Conclusion

Isolated thymic LR is very uncommon. CHL relapse should be suspected when increasing tumor masses are present in distant sites outside of the thymic area. Conversely, if regrowth of lymphoma in other sites can be excluded, isolated thymic mass after CTX likely represents RTH.     

Computerized tomography and ultrasonographic findings in massive thymic hyperplasia. Case discussion and review of current concepts

Massive thymic hyperplasia in the neonate and young infant can be difficult to diagnose. Differentiation from neoplastic lesions may require thoracotomy for a pathologic specimen. We review a case in a 15-month-old child referred to our institution and discuss the radiographic, ultrasound, and computerized tomographic features of hyperplastic thymic tissue. We review current concepts of the hyperplastic thymus as an anterior mediastinal mass in infancy.     

Thymic calcifications in histiocytosis X

We report a case of an infant with pulmonary histiocytosis X with punctate thymic calcifications on conventional CT without an anterior mediastinal mass.     

A case report of hyperthyroid-associated thymic hypertrophy in a child,presenting as an anterior mediastinal mass

We present the case of an 8-year-old boy with an anterior mediastinal mass and signs of hyperthyroidism. The anterior mediastinal mass had radiologic characteristics suggestive of thymic hypertrophy and regressed with antithyroid therapy. Though thymic hypertrophy is a known manifestation of hyperthyroidism, this is the youngest reported case. In selected cases, the diagnosis may be made based on the clinical picture, radiologic appearance, and response to antithyroid therapy without the need of a thymic biopsy or thymectomy.     

Thymic enlargement in association with hyperthyroidism

A female adolescent with hyperthyroidism was found to have an anterior mediastinal mass. Radiological investigation of this mass was consistent with thymic enlargement. Chest roentgenograms one year after treatment showed resolution of the mediastinal mass. A non-invasive investigational approach to such patients is suggested based on a review of the pathological literature.     

Thymic Hyperplasia Associated with Graves’ Disease in a 10-year-old Boy

Thymic hyperplasia associated with Graves’ disease is rarely reported in children, although it is not uncommon in adults. Occasionally, an enlarged thymus presents as an anterior mediastinal mass on a radiographic examination. Such patients often undergo invasive procedures such as a thymus biopsy or thymectomy because of suspected malignancy. However, an enlarged thymus with Graves’ disease is known to shrink after treatment with antithyroid drugs. Therefore, recognition of this benign course would avoid unnecessary surgical resection. This report presents the case of a 10-yr-old boy with Graves’ disease complicated with an anterior mediastinal mass. Computed tomography showed a homogenous mass with no invasion into the surrounding tissue. A gallium-67 scintigraphy showed no abnormal uptake. Shrinkage of the mass after treatment with an antithyroid drug (methyl-mercaptoimidazole) supported the diagnosis of thymic hyperplasia with Graves’ disease. This case report illustrates two important points. First, pediatricians should be aware that thymic hyperplasia can coexist with Graves’ disease, even in children. Second, close radiographic assessment would support a diagnosis of thymic hyperplasia and eliminate invasive diagnostic procedures.     

Rebound thymic hyperplasia five years after chemotherapy for Wilms' tumor

Rebound thymic hyperplasia following chemotherapy is well documented, usually occurring within the first year. A delayed presentation makes distinction from an anterior mediastinal mass problematic in view of the increased risk of a second primary malignancy in pediatric cancer survivors. An unusual case of rebound thymic hyperplasia is described, presenting five years after completion of chemotherapy for Wilms' tumors.     

Thymic uptake of gallium-67 citrate in a healthy 4 year old boy

Gallium uptake in a mediastinal mass has been most often seen with lymphoma. A case is reported of thymic uptake in an otherwise healthy 4 1/2 year old boy who had recently had pneumonia. Serial films always showed an unchanging prominent though normal thymus and follow up gallium scans showed disappearance of thymic uptake. This and other similar cases indicate the need to consider a non-neoplastic thymus when gallium accumulation is noted in the anterior mediastinum of a child.     

Thymic rebound following successful chemotherapy of B-lymphoma in an adolescent boy

Four months after termination of successful chemotherapy for epipharyngeal B-non-Hodgkin lymphoma, an enlarging anterior mediastinal mass was discovered in a 15-year-old boy. There was no other suspicion of tumour recurrence. A simple thymic rebound was likely and a conservative management was chosen. Follow up for more than 12 months was uneventful. The frequency of thymic hyperplasia after termination of chemotherapy is discussed. It is a benign immunological rebound phenomenon and does not require operative intervention.     

Split liver transplantation for retroperitoneal immature teratoma masquerading as hepatoblastoma

Extragonadal teratoma originating from the retroperitoneum represents less than 5% of all teratomas and accounts for less than 10% of all pediatric retroperitoneal neoplasms. To date, there has been no report of teratoma managed with LT. This study reports an infant aged 3 months with retroperitoneal immature teratoma involving the hepatic hilum, refractory to chemotherapy and treated with LT. The patient was referred to our hospital for management of a growing abdominal mass. Histopathology of a fine needle biopsy of the lesion suggested the possibility of a hepatoblastoma with teratoid features. Cisplatin‐based chemotherapy was initiated, but rapid growth of the tumor encasing the hepatic artery proper was detected, even after two cycles of chemotherapy. A split LT was carried out, and pathological examination of the explanted liver revealed the involvement of numerous neuroepithelial components, confirming the diagnosis of a Norris grade 3 immature teratoma. The patient recovered well and was discharged on day 19 post‐LT. As on date, on postoperative day 240, he has completed seven cycles of a 12‐cycle vinblastine and doxorubicin‐based adjuvant chemotherapy.     

Concurrent development of a thymic cyst and mediastinal Hodgkin's disease

A case is presented of a young adult female who presented with nodular sclerosing Hodgkin's disease and a mediastinal mass that proved to be a thymic cyst. Prior to this illness, a chest x-ray had been obtained that did not show a mediastinal mass. This case illustrates that thymic cysts may arise simultaneously with mediastinal Hodgkin's disease, rather than as a result of treatment or being present congenitally.     

The coexistence of thymic carcinoma and multiple granulomas in a Turkish child

Thymic carcinoma, which is a thymic epithelial neoplasm with obvious cytologic atypia, is a rare neoplasm. The authors report on a 10-year-old boy who presented with respiratory distress due to bulky anterior mediastinal mass. Histological and immunohistochemical studies confirmed a lymphoepithelioma-like pattern thymic carcinoma. In addition, evaluation of the specimen showed foci of caseation and multiple granulomas with extensive central necrosis within the thymic tissue. The child received chemotherapy, followed by surgery and radiotherapy. To rule out difficulties of tuberculosis he also received antituberculosis therapy. Two years after cessation of treatment, he is still in remission for thymic carcinoma.     

Barriers to ideal outcomes after pediatric liver transplantation

Long‐term survival for children who undergo LT is now the rule rather than the exception. However, a focus on the outcome of patient or graft survival rates alone provides an incomplete and limited view of life for patients who undergo LT as an infant, child, or teen. The paradigm has now appropriately shifted to opportunities focused on our overarching goals of “surviving and thriving” with long‐term allograft health, freedom of complications from long‐term immunosuppression, self‐reported well‐being, and global functional health. Experts within the liver transplant community highlight clinical gaps and potential barriers at each of the pretransplant, intra‐operative, early‐, medium‐, and long‐term post‐transplant stages toward these broader mandates. Strategies including clinical research, innovation, and quality improvement targeting both traditional as well as PRO are outlined and, if successfully leveraged and conducted, would improve outcomes for recipients of pediatric LT.     

Parental functioning improves the developmental quotient of pediatric liver transplant recipients

Psychomotor development in pediatric liver transplant (LT) recipients depends on several factors. Our aim was to evaluate the importance of parental involvement and family dynamics on psychomotor development by assessing (i) children and parents individually, (ii) the parent–child relationship, and (iii) the correlation between parental functioning and patient outcome, all before and after LT. Age‐appropriate scales were used before and after LT. Twenty‐one patients, 19 mothers, and 16 fathers were evaluated. Developmental quotient (DQ): No subjects scored in the “very good” range. The proportion of children with deficits increased from LT to two yr: 17.6% vs. 28.6%. Subjects 0–2 yr were more likely to have normal DQ at transplant (66.7% vs. 50% for older children). Abnormal DQ was more prevalent two yr post‐LT in children older at LT (p = 0.02). The mother–child relationship was normal in 59% of families pre‐LT and in 67% at two yr. The relationship was more favorable when the child received a transplant as an infant (p = 0.014 at 12 months post‐LT). Normal DQ was associated with higher maternal global functioning score pre‐LT (p = 0.03). Paternal performance scores were higher than maternal scores. Children transplanted after two yr of age suffer greater long‐term deficits than those transplanted as infants.     

THE COEXISTENCE OF THYMIC CARCINOMA AND MULTIPLE GRANULOMAS IN A TURKISH CHILD

Thymic carcinoma, which is a thymic epithelial neoplasm with obvious cytologic atypia, is a rare neoplasm. The authors report on a 10-year-old boy who presented with respiratory distress due to bulky anterior mediastinal mass. Histological and immunohistochemical studies confirmed a lymphoepithelioma-like pattern thymic carcinoma. In addition, evaluation of the specimen showed foci of caseation and multiple granulomas with extensive central necrosis within the thymic tissue. The child received chemotherapy, followed by surgery and radiotherapy. To rule out difficulties of tuberculosis he also received antituberculosis therapy. Two years after cessation of treatment, he is still in remission for thymic carcinoma.     

Two‐step transplantation for primary hyperoxaluria: A winning strategy to prevent progression of systemic oxalosis in early onset renal insufficiency cases

Several transplant strategies for PH1 have been proposed, and LT is performed to correct the metabolic defects. The patients with PH1 often suffer from ESRD and require simultaneous LKT, which leads to a long wait due to the shortage of suitable organ donors. Five patients with PH1 underwent LDLT at our institute. Three of the five patients were under dialysis before LDLT, while the other two patients were categorized as CKD stage 3. An isolated LDLT was successfully performed in all but our first case, who had complicated postoperative courses and consequently died due to sepsis after retransplantation. The renal function of the patients with CKD stage 3 was preserved after LDLT. On the other hand, our second case with ESRD underwent successful LDKT six months after LDLT, and our infant case is waiting for the subsequent KT without any post‐LDLT complications after the early establishment of PD. In conclusion, a two‐step transplant strategy may be needed as a life‐saving option for patients with PH1 and may be possible even in small infants with systemic oxalosis. While waiting for a subsequent KT, an early resumption of PD should be considered from the perspective of the long‐term requirement of RRT.     

High‐dose chemotherapy followed by autologous peripheral blood stem cell transplantation for recurrent primary mediastinal malignant germ cell tumor: A case report

A 15‐yr‐old boy presented with an anterior mediastinal mass, multiple lung metastases and obstruction of the left brachiocephalic vein, the superior vena cava and the subclavian vein. Tumor biopsy by CT guidance confirmed a diagnosis of GCT. Five courses of BEP therapy were performed, and CT of the chest revealed reduction in the anterior mediastinal mass and disappearance of the multiple lung metastases. We performed the anterior mediastinal mass extraction followed by adjuvant chemotherapy consisting of ICE and TIP. However, the AFP levels became elevated soon after. Abnormal accumulation was observed in the right upper lung by DW‐MRI. After the operation, two courses of TI chemotherapy and two courses of HDCT followed by auto‐PBSCT were performed. He was complicated with auditory disorder and renal dysfunction. Although HDCT followed by auto‐PBSCT was effective for the relapsed primary mediastinal GCT, a treatment strategy avoiding late complications is warranted.     

Thymic lymphoepitheliomalike carcinoma in children: clinicopathologic features and molecular analysis

Thymic lymphoepitheliomalike carcinoma (LELC) in children is extremely rare and we report 2 such cases with molecular analysis of Epstein-Barr virus (EBV) and its encoded latent membrane protein-1 as well as a literature review. Both of our patients were male, presented with a huge anterior mediastinal mass, expired within a year after diagnosis despite treatment. There were altogether 9 cases of thymic LELC in children. Their common clinical features include a male predominance, large tumor size, advanced clinical stage, and poor clinical outcome. All cases were associated with EBV and nearly half developed concurrent hypertrophic osteoarthropathy (HOA). Thymic LELC in children is an aggressive EBV-associated malignant tumor frequently accompanied by HOA. We proposed that EBV might play a role in the development of HOA through the interactions of latent membrane protein-1, vascular endothelial growth factor, and cyclooxygenases-2.