Purpose or Case Report: Fatty falciform ligament appendage torsion (FFLAT) is a rare phenomenon as there are only two reported pediatric cases of falciform ligament fatty appendage torsion in the literature. In this case, the diagnosis was established via ultrasound (US) and confirmed with computed tomography (CT). US showed an echogenic, ill-defined mass in the epigastric region that extending into the falciform ligament. CT showed the “hyperattenuating rim” sign. This report is the first reported female pediatric case of FFLAT that was diagnosed with US and CT, given a trial of analgesics, and definitively cured via minimally invasive surgical excision.

A 13-year-old female presented to the emergency department with episodic waxing and waning abdominal pain for three days. The pain had localized to the mid-epigastrium and worsened with deep inspiration. On examination, vital signs were within normal limits. Focal tenderness was elicited upon palpation of the epigastrium. Laboratory evaluation revealed a mild leukocytosis 14.2 x 109/L, normal range (3.9-10.6 x 109/L).

Methods & Materials:
Results: Ultrasound demonstrated an irregularly marginated hyperechoic mass in the epigastric region that extended into falciform ligament. Confirmatory CT scan of the abdomen/pelvis with IV and oral contrast revealed mass-like stranding of the intraperitoneal fat in the epigastric region with a classic ovoid hyperattenuating rim sign. The vessels extending into the falciform ligament did not demonstrate contrast enhancement further raising concern for torsion.

Surgical consultation was obtained. Conservative management was recommended via a trial of non-steroidal anti-inflammatory medication. Despite several weeks of treatment, the patient’s pain persisted without significant improvement. Transumbilical laparoscopic excisional findings strongly suggested an acute on chronic inflammatory process confined to the fatty appendage of the falciform ligament. The pathologist described the resected mass as fibrofatty rubbery tissue. The pre-operative diagnosis of FFLAT was confirmed. The patient was found to have complete resolution of pain at her two-week post-operative follow-up.
Conclusions: This case reiterates the clinical multidisciplinary team approach required to diagnose the rare case of FFLAT in a pediatric patient. It also demonstrates careful observation of conservative management, and optional minimally invasive surgical resection for patients with persistent symptoms.