Outcome of residual mediastinal masses of thoracic lymphomas in children: impact on management and radiological follow-up strategy.

BACKGROUND: Following treatment with chemotherapy and radiotherapy, patients with thoracic lymphomas may demonstrate benign residual mediastinal masses, composed of inflammatory, fibrous or necrotic tissue. Because of the potential risk of viable tumour cells within the mass, histological verification of the nature of these masses may be requested. OBJECTIVE: To study the outcome of thoracic lymphomas in children in order to optimise the radiological follow-up strategy of residual mediastinal masses (RMM). MATERIALS AND METHODS: A retrospective study of 39 children [24 with Hodgkin's disease (HD), 10 with non-Hodgkin's lymphoma (NHL), and 5 with anaplastic lymphoma (AL)]. The results of chest X-rays (CXR) and thoracic CT performed at the time of re-assessment were compared with the histology of the residual masses (n = 11) or the clinical course (n = 28). RESULTS: At the time of re-evaluation, 16/39 patients had residual mediastinal enlargement (RME) on CXR, and 18/39 patients had RMM on CT. Good concordance was observed between the two imaging modalities (K = 0.69). Two children with a RMM died from extra-mediastinal progression. Two children with NHL had active residual mediastinal lesions but neither had RMM. Sixteen cases of RMM were observed in the remaining 35 children and 9 of these masses were histologically verified as benign. A favourable course was observed in these 35 cases. CONCLUSIONS: RMM are frequent and generally benign. They are well shown on CXR and have a non-specific appearance on CT. Except when required by a treatment protocol, they could be submitted to further radiological follow-up before contemplating surgical verification.

Congenital muscular dystrophy: use of brain MR imaging findings to predict merosin deficiency.

PURPOSE: To evaluate the brain magnetic resonance (MR) imaging findings in patients with the "classic" form of congenital muscular dystrophy (patients with normal intelligence) in relation to the absence of merosin, a recently identified molecular component in the basement membrane of muscle fiber. MATERIALS AND METHODS: Brain MR images in 15 patients (13 children, two adults) were reviewed and correlated with the patient's merosin status. Merosin was evaluated by means of immunocytochemical study of specimens from muscle biopsy. RESULTS: Nine patients had merosin deficiency. All patients had diffuse white matter alterations similar to those seen in cases of leukodystrophy. Periventricular and subcortical white matter were involved. The corpus callosum and internal capsule were spared. Follow-up MR images were available in two patients; changes were nonprogressive. White matter signal intensity was normal in the six patients with normal uniform labeling against merosin. Ventricular dilatation and cortical atrophy were observed in both groups. CONCLUSION: Diffuse white matter changes resembling those seen with leukodystrophy may be a valuable criterion for diagnosis of merosin deficiency in patients with classic congenital muscular dystrophy.