Erythematous Abdominal Nodule

The Diagnosis: Foreign Body Reaction With Sinus Tract

A delayed foreign body reaction is a rare complication of retained temporary pacing wires following cardiovascular surgery. These epicardial pacing wires are important for the management of postoperative arrhythmia and normally are removed by external traction after normal rhythm has been re-established. However, it is not uncommon for these wires to be cut at the skin surface in the setting of difficult removal, as retained pacing wires generally are viewed as benign.¹ These reactions often take years after placement of the pacing wire to present themselves and most often resolve with either complete removal of the wire or resection of the distal end.²

Our patient was referred to dermatology and underwent a shave biopsy. Results were consistent with chronic inflammatory granulation tissue. Bacterial tissue culture grew Staphylococcus epidermidis. Cultures for acid-fast bacilli and fungi were negative. The patient was referred to cardiothoracic surgery. Computed tomography identified a retained temporary pacing wire extending to the base of the lesion. The lesion was excised and the distal aspect of the pacing wire was removed, which resulted in resolution of the nodule.

The differential diagnosis includes pyoderma gangrenosum, nodular basal cell carcinoma, Sister Mary Joseph nodule, and pyogenic granuloma. Pyoderma gangrenosum is a neutrophilic dermatosis that presents as a rapidly progressing, painful, necrotic ulcer. It is classically associated with inflammatory bowel disease and other systemic diseases but also can occur in isolation.³

Nodular basal cell carcinomas often develop in chronically sun-exposed areas of the body. Morphologically, they present as pink, pearl appearing papules with rolled borders and overlying arborizing telangiectasia. Nodular basal cell carcinomas may present with recurrent bleeding but typically do not have continuous drainage.⁴

Sister Mary Joseph nodule represents a periumbilical lymphatic metastasis from an underlying (usually intra-abdominal) malignancy. It typically presents as an umbilical or periumbilical nodule measuring 0.5 to 15 cm in diameter. The nodules often are painful and discharge a serous fluid. It is estimated that they are present in 1% to 3% of cases of abdominopelvic malignancy, but Sister Mary Joseph nodules also have been reported in several other types of solid organ tumors.⁵

Pyogenic granuloma is a benign vascular lesion that classically develops rapidly over the course of a few weeks. It often presents as a single red, moist, friable papule with a collarette of scale and frequently is associated with pain, bleeding, and ulceration. Keratinized skin or mucosa can be affected, and pyogenic granuloma is most common in children and young adults.⁶