Third lumbar transverse process syndrome with acute abdominal pain as the main clinical manifestation

Rationale: Third lumbar transverse process syndrome is an uncommon musculoskeletal cause of referred abdominal pain. Because acute abdominal pain is appropriately evaluated first for visceral, vascular, urinary, and surgical emergencies, a spinal or paraspinal pain generator may be overlooked. Patient concerns: A 66-year-old man presented with persistent left lower-quadrant abdominal pain radiating to the left lower back. Baseline pain intensity was 7/10 on a VAS, and the pain was aggravated by postural change, standing, and walking. Diagnoses: Serial laboratory tests, endoscopy, ultrasonography, CT/CTA, and specialist consultations did not identify a visceral, urinary, surgical, or hemodynamically significant vascular disorder sufficient to explain the pain. Targeted musculoskeletal examination showed focal tenderness and increased soft-tissue tension around the left L3 transverse process, movement-related pain, and a visually estimated compensatory apparent leg-length discrepancy. These findings supported a clinical diagnosis of third lumbar transverse process syndrome presenting as referred abdominal pain. Interventions: The patient received Tuina manual therapy, two acupotomy closed-release procedures at palpation-defined tender points in the left lumbar and gluteal regions, and adjunctive pharmacotherapy. Outcomes: At discharge on February 9, 2021, the abdomen was soft without tenderness or rebound tenderness. Abdominal pain had resolved completely at the 2-week follow-up. Routine annual telephone follow-up of former inpatients was then conducted once yearly for 3 years, with no recurrence reported. Lessons: After urgent abdominal and vascular disorders have been excluded, history taking and targeted examination of the lumbar transverse processes may identify a musculoskeletal source of otherwise unexplained abdominal pain.