Pediatric Oncology [1]. We would like to share our experience with AT patients having HD.Between 1988 and 1998, we treated six children with AT and HD. Of these, five were females, the age at diagnosis of HD was 8 years in five patients and 6.5 in the other. The mean age in 210 Turkish children with HD treated in our center was 8 years, and 69% of the cases had mixed-cellularity [2]. The ages at diagnosis of HD in our AT patients are similar, and are in accordance with the two patients reported by Irsfeld et al. They noted that both their patients had mixed-cellularity HD [1], which also was found in 42% of the cases of AT reported by Mueller and Pizzo [3]. In contrast, the histologic subtypes in our six AT patients were as follows: four lymphocyte-depletion-type, one mixed-cellularity, and one unspecified.Respiratory infections are the principle cause for morbidity and mortality in AT patients. Ersoy et al. [4] reported that frequent sinopulmonary infections were the cause of death in two-thirds of patients who died in a series of 160 AT patients from our hospital. Another interesting finding in our patients was that plain chest X-ray films displayed evidence of mediastinal disease in five cases, three of them having accompanying cavitating pulmonary infiltrates. Thoracic computed tomography (CT) was available for these three patients in whom cavitations and pulmonary infiltrates were clearly demonstrated. Irsfeld et al. did not mention CT findings in their two patients with thoracic disease. In AT patients with HD, it might be difficult to interpret the basis for the pulmonary findings, especially when mediastinal involvement is apparent because primary pulmonary parencymal HD without lymph node involvement is exceedingly rare [5], and cavitation of the pulmonary lesions is even rarer [6]. Since data regarding the patterns of pulmonary involvement in patients with AT and HD are lacking, the development of cavitating pulmonary lesions in three of our six AT patients with HD raises the question of a possible common underlying pathophysiology in these patients.