Largest reported lipoma in the United States of America

A woman in her early 60s presented for evaluation of an asymptomatic left groin mass. CT imaging noted a large fatty tumour replacing the majority of the abdominal and pelvic cavities. The patient underwent uneventful resection of a 53×36×9 cm mass of the retroperitoneal (RP) space. The pathology report was compatible with a lipoma. This is the largest noted RP lipoma in the US literature. In this case report, we also offer a literature review of the diagnosis and management of fat-containing retroperitoneal masses.