Unusual complication following placement of an epidural catheter

We report an unusual complication following placement of a thoracic epidural catheter in a patient that had undergone surgery for pulmonary metastases of a malignant melanoma. The intra- and postoperative course was initially without complications. At 2 days, there was a small, conspicuous swelling above the site of epidural puncture, which was neither reddened nor painful. No neurological deficits were observed, and the patient explained that he had been aware of the swelling for more than 6 months; thus, the epidural catheter was not deemed to be responsible. After catheter removal on day 4, an apparently purulent fluid drained from the puncture site. Although the patient had not reported this in the initial medical examination, he now explained that this cutaneous process had been squeezed out by his wife several times before. We initially obtained an exudate by means of ultrasound-guided puncture, and two epidermal cysts were detected on subsequent magnetic resonance imaging (MRI). The epidural catheter had been placed through one of these epidermal cysts. After reassessing the medical files, we found the earlier reports of two positron emission tomographies in which two epidermoid cysts were described at the level of thoracic vertebra 5/6 and 6/7. Facklamia hominis was detected in the pure culture. To avoid bacterial infection, we treated the patient for 7 days with antibiotics. The clinical course was without further pathological findings.