Persistent Depression of the Lambda Site with Progressive Skull Deformity May Be a Sign of Suture Closure: Case Series and Pathologic Consideration.

ABSTRACT

BACKGROUND: Flat head syndrome (FHS) sometimes occurs when a baby maintains the same head position during the first several months of life, causing a skull deformity. FHS usually improves with time and natural growth, although some show aggravation against conservative treatment. We reviewed pathologically proved early closure of skull suture that may be seen secondary to FHS. METHODS: The clinical and radiologic findings of the patients who showed progressive skull deformity resembling FHS were retrospectively reviewed. All the patients underwent surgical treatment and pathologic specimens were obtained. RESULTS: The detected patients included two 5-month-old infants and one 1-year-old child. The former were conservatively treated without any obvious premature suture closure on computed tomography (CT), and later developed progressive tower-like skull deformities. The infants were diagnosed with possible premature fusion of lambda site and underwent removal around lambda depression (LD). The latter showed evident sagittal suture closure on CT with digital markings, and was diagnosed with increased intracranial pressure and underwent cranioplasty of posterior expansion. Histopathologic specimens obtained from the patients' resected sutures showed irregularly narrowed suture structure with ossification and fibrous tissue proliferation within them, supporting the diagnosis of premature closure of the sagittal sutures. Their postoperative courses were uneventful, and their skull deformities subsequently improved. CONCLUSIONS: Conservative therapy-resistant progressive occipital skull deformity with LD may be a sign of early suture closure, even if CT does not show obvious suture closure. The findings are helpful for early diagnosis and might lead to minimal invasive surgery if needed.