Soft right chest wall swelling simulating lipoma following motor vehicle accident: transdiaphragmatic intercostal hernia. A case report and review of literature

Abstract

Introduction

Intercostal herniation of abdominal contents through a diaphragmatic defect is rare. We report a case of transdiaphragmatic intercostal hernia secondary to blunt trauma, initially misdiagnosed as lipoma, later confirmed by CT scan.

Methods

We present a case of a 77-year-old who was involved in a motor vehicle accident and sustained a hand fracture. Later that year his wife noticed an egg-shaped soft swelling on his right chest wall. He was seen in the minor operative clinic, and a lipoma excision was attempted when it was found to be an intercostal hernia. Colon was seen in the hernial pouch.

Results

Anatomically, the chest wall is weak from the costochondral junction to the sternum because of lack of external intercostal muscle support, and from the costal angle posteriorly to the vertebrae because of lack of internal intercostal musculature. The integrity of the thoracic cage is disrupted by tears of the intercostal musculature between fractured ribs. This defect leads to separation of the ribs and development of a potential weakened space for hernia. This chest wall muscular weakness can occur anywhere and can be more pronounced if it occurs at anatomically weakened areas. In the presence of associated diaphragmatic rupture, there is herniation of abdominal viscera. The treatment includes immediate surgical repair either by abdominal or thoracoabdominal approach.

Conclusions

A thorough physical examination may suggest the diagnosis, but confirmation by chest radiograph, CT scan, and sometimes by gastrointestinal contrast studies is often helpful for preoperative planning. A high index of suspicion for diaphragmatic injury or intercostal herniation during the initial evaluation, coupled with chest and abdominal diagnostic testing once the patient is stable, can avert undue delay in diagnosis and catastrophe from incarceration of a hernia.