Verrucous carcinoma on a chronic sacral pressure ulcer in a patient with meningomyelocele. Case report and review of the literature

1 Case report

Mr G. was born in 1977 with meningomyelocele, operated in 1978, and presented complete AIS A T12 paraplegia and hydrocephalus with moderate mental retardation. His surgical antecedents were: ventriculoperitoneal shunt, augmentation enterocystoplasty and anti-reflux surgery in 1990, Salter pelvic osteotomy + Sharrard psoas muscle transfer in 1994.

In 2004 we managed the patient for the first time, for a sacral pressure ulcer, in the form of a cryptic and keratotic lesion. It was already a recurrence. In 2005, purulent discharge makes us practice an MRI, showing subcutaneous infiltration involving the sacrum (sacral osteomyelitis is suspected) and a cryptic zone in contact with the rectal wall.

A first musculocutaneous flap permitted a first biopsy of the sacral lesion in June 2005. Histological examination revealed chronic ulceration compatible with a diagnosis of pressure ulcer. The initial postoperative course was favourable, but at the beginning of 2006, purulent discharge on sacrum recurred, explained at MRI by persistence of a blind perineal fistula along the levator ani muscles and another fistula extending towards the coccyx (no signs of intestinal fistula). After two flap revisions in 2006 and 2007 allowing evacuation of large infected haematoma, closure of fistulas and after adapted dual-agent antibiotic therapy (against always the same germ: Proteus mirabilis), the patient has healed and regained his autonomy. All histological examinations were compatible with a chronic wound with no sign of malignancy.

No complication was observed during a 3-year period of outpatient follow-up. An annual follow-up CT urography incidentally revealed a sacral mass ( Fig. 1 ). MRI confirmed the presence of an infiltration with a paraspinal collection extending from L3 to the sacrum associated with sacral bone destruction, suggesting an infectious process ( Fig. 2 ).

The patient was admitted to hospital for a infected stage 3 sacral pressure ulcer and new fistulas. He was malnourished, had chronic anemia and signs of sepsis. In a multidisciplinary consultation meeting (MCM), we decided to practice excision of the pressure ulcer and exploration of the fistulas (no intestinal fistula founded), one on the right hip. Histological examination revealed the presence of epidermal cysts with no histological signs of malignancy. Triple agent antibiotic therapy was initiated.

An MRI performed in February 2011 showed no improvement, so the patient was reoperated for an oncologic-like resection including: sacrum, right sacro-iliac joint and the right Sharrard psoas muscle transfer and resection of the head and neck of the right femur due to the suspected infectious process. The macroscopic appearance evoked secondarily infected epidermoid cyst. Histological examination showed a squamous cell proliferation with multiple large lobules and marked inflammatory infiltrate, sometimes presenting features of granulation with several sites of bone metaplasia. The diagnosis was impossible to confirm in view of the fragmented nature of the sample, it could have been a pseudocarcinomatous epidermal hyperplasia or a verrucous carcinoma.

The postoperative course was initially uneventful, but recurrence of the purulent discharge was observed in May 2011. Pelvic MRI ( Fig. 3 ) showed reactivation of the purulent collections and inflammatory signs, accompanied by blind fistulous tracks in the right buttock and left pararectal region.