Abstract
BACKGROUND: Adrenal haemangiomas are exceptionally rare benign vascular tumours, usually discovered incidentally and measuring only a few centimetres. But in rare cases, lesions exceeding 20 kg are distinctly uncommon and pose major diagnostic and operative challenges. CASE PRESENTATION: A 67-year-old woman presented with six months of progressive abdominal distension, early satiety, and exertional dyspnea on a four years background of intermittent left loin pain. Her medical history includes HTN, T2DM, AF and heart failure. No surgical history was reported. Imaging revealed a giant left retroperitoneal mass displacing adjacent viscera. Hormonal evaluation showed hypothyroidism, consistent with a non-functional adrenal lesion. Tumour markers were negative. After multidisciplinary discussion, open trans-abdominal excision was performed. Operative time was 4 h 45 min with an estimated blood loss of 500 mL. Two units of packed red blood cells and two units of plasma were transfused pre-operatively and the same post-operatively. She underwent midline laparotomy. The tumour, densely adherent to aorta, inferior vena cava and ureter, was removed en‑bloc using meticulous dissection and a radiofrequency scissor. Concomitant umbilical hernia was repaired with a 30 × 30 cm pre‑peritoneal polypropylene underlay mesh (5 cm overlap). The excised specimen weighed 20.1 kg, verified intra-operatively. Histopathology confirmed a cavernous haemangioma without atypia or malignancy. Post-operative recovery was uneventful. Follow-up at two months with ultrasound showed no recurrence. CONCLUSIONS: Although giant adrenal cavernous haemangioma is benign, it can mimic other retroperitoneal tumours and demands meticulous pre-operative optimisation and multidisciplinary planning. Surgical excision remains the treatment of choice, and structured long-term surveillance is advised. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12893-026-03553-4.