gms | German Medical Science

Introduction: Tonsillar hypertrophy caused by the progressive accumulation of partially degraded glycosaminoglycans (GAGs) within the cells is a typical symptom in patients with mucopolisaccharidoses (MPS). Patients with MPS suffer from alterations of the skeleton, the heart and the lung. Typically ear, nose and throat are involved, too. Characteristical stigmata are facial dysmorphism, a widened nasal bridge, large nares and thickened lips. Later gingival hyperplasia, gapped teeth and a macroglossia are seen.

Tonsillar hypertrophy and alterations of the larynx and hypopharynx lead to a significant upper airway obstruction. For half of the patients adenoidectomy, for a third of them tonsillectomy is reported. We studied the tissue of adenoids and tonsils of patients suffering MPS with special regard to characteristic morphological features which could serve as a marker for the diagnosis.

Methods: We examined the adenoids of 87 patients and the tonsils of 4 patients with MPS and controls (2 patients with MPS I, 7 MPS II, 5 MPS IV und 10 MPS VI and 63 controls). These examinations were repeated in a blinded manner by two pathologists.

Results: The key feature observed was a subepithelial “clearing” on scanning magnification, induced by perivascular accumulation of foamy marcophages. Similar agglomerates could sometimes be found at the base of the lymphoid follicle.

In the blinded assessment a specificity of 92% (100% for adenoids) and a sensitivity of 100% were achieved. The inter-observer-variability was 92% (100% for adenoids).

Tonsillectomy specimens contain an innate pitfall, as marked subepithelilal fibrosis can lead to a false-negative evaluation.

Conclusions: For the most frequent forms of MPS enzyme replacement therapy is available. An early diagnosis is critical for the success of this therapy and can be realized by qualified histological examination.