Delayed Subaponeurotic Fluid Collection in a Neonate: A Case Report

Abstract

Delayed subaponeurotic fluid collection (DSFC) is a rare cause of scalp swelling that typically presents in healthy-term babies during the second month of life. It is a benign, self-limited condition that requires only conservative management. We present a case of DSFC in a male infant who was brought to our emergency department by his parents at the age of 52 days because of concerns about a newly noticed fluctuating scalp mass. The baby was managed conservatively, and the DSFC completely resolved after three weeks. We describe and discuss the diagnostic workup conducted and the management plan implemented in line with the scientific literature and similar cases previously reported. Given its benign but rare nature, pediatricians and neurosurgeons should be more aware of DSFC as a potential entity in the differential diagnosis of fluctuant scalp swellings. Early recognition can prevent unnecessary investigations or interventions and provide reassurance to parents regarding the condition's benign course. To the best of our knowledge, this is the first reported case in Saudi Arabia, the second reported case from the Middle East, and the second from Asia.

Keywords: collection; delayed; fluid; neonate; subaponeurotic.

Figure 1. The right posterior parietal soft scalp swelling as presented in the emergency department at 52 days of age.

Figure 2. Cranial ultrasonography images

Cranial ultrasonography image in coronal orientation done on admission of the case. (1) Subaponeurotic fluid collection with cerebrospinal fluid (CSF)-like hypodensity. (2) Galea aponeorotica layer of the occipitofrontalis muscle appearing as a thin hyperdense scalp layer. (3) The isodense irregular fibrous sagittal suture line marking the midline of the skull between the two pariteal bones. (4) The right parietal bone as a hyperdense structure following the curvature of the skull clavaria.

Figure 3. CT brain images of coronal orientation done on admission of the case.

A (left image) soft tissue image showing a subaponeurotic scalp swelling crossing the sagittal suture line with no associated intracranial pathology underneath. B (right image) Bone window of the same image showing no detectable skull fractures related to the scalp swelling.