“Hiding beaver tail liver”: a rare case report of a beaver tail liver lookalike variant located medially to the spleen, mimicking a perisplenic hematoma

Abstract

Background: Liver lobe anatomic variations are uncommon and may often cause clinical difficulties. We present a trauma patient with a previously unreported (to our knowledge) hepatic morphology, which was initially misdiagnosed as a possible perisplenic hematoma, leading to unnecessary further investigations. Case presentation: A 32-year-old male patient was brought to our hospital’s emergency department following a low-energy motor vehicle accident. The patient was ambulatory, had a GCS of 15/15, and appeared hemodynamically stable with normal hematocrit (Hct)/hemoglobin (Hb) blood counts. No clinical signs/symptoms of bleeding were noted, and no significant complaints were documented, besides minor left flank tenderness with overlying abrasions. The patient's past medical history was insignificant. FAST (Focused Assessment with Sonography for Trauma) scan performed gave the impression of a crescent-shaped hypoechoic lesion/collection medially to the spleen, raising suspicion of a perisplenic hematoma. Subsequent computed tomography (CT) scan displayed no trauma-related findings, while the suspected hematoma was seen to correspond to variant left hepatic lobe morphology. Conclusion: The “hiding beaver tail liver” (HBTL) is a hepatic morphology variant encountered when the lateral part of the left liver lobe (beaver’s tail) extends across the midline and lies medially to the visceral surface of the spleen, following an acute angulation (in hiding). As it can mimic true pathology, familiarity with this morphology is crucial to avoid false diagnosis and unnecessary investigations.