1 Department of General, Visceral, Vascular and Thoracic Surgery 2 Department of Medicine, Section of Paediatric Nephrology, Medical Faculty Humboldt University, Charité, Campus Mitte Berlin, Germany
Sir,
A desmoid tumour was first described by MacFarlane in 1832 [1]. The aetiology of this tumour entity is not fully understood. Predisposing conditions of desmoid tumours include various factors such as surgical trauma, Gardner's syndrome, endocrine factors and familial occurrence of the tumour [2]. More than a hundred observations of this tumour have been described in the literature. Here we report a case of two metachronic desmoid tumours in the abdominal rectus muscle arising at the sites of insertion of silastic peritoneal Tenckhoff catheters, 5 and 8 years following removal of the catheters.
Case
In 1998, a 25-year-old white female complained of a painful swelling in her left abdominal wall, which she had had for 3 months. Due to glomerulonephritis, she had suffered from complete renal insufficiency since 1991. Before renal transplantation in 1997, she had received peritoneal dialysis for 2 years via a Tenckhoff peritoneal catheter through the right and left rectus muscle. Since 1997 she had been taking cyclosporin (Novartis, Bern, Switzerland), 200 mg/day. Clinical examination revealed a painful, palpable mass in the left upper rectus muscle directly under the former insertion site of her peritoneal dialysis catheter. A CT scan displayed a solid tumour in the rectus muscle, which could not be definitely distinguished from the lower rectus sheath (Figure 1). Following surgical excision of the tumour, histological evaluation showed it to be a desmoid tumour. The post-operative course of the patient was uneventful and no signs of tumour recurrence were found during a follow up of 2.5 years.
|
Comment
Desmoid tumours represent only 0.03% of all tumours of the abdominal wall [2]. Despite this localization they have also been described at different extra-abdominal sites such as the breast, head and neck, bladder and intra-abdominal locations. Patients with Gardner's syndrome are at a 1000-fold increased risk of developing a desmoid tumour compared with the general population. Two types of this tumour entity can be differentiated. One is the superficial, slow growing desmoid with low tendency to involve deep structures, and the other is a deeper desmoid tumour with highly aggressive local growth characteristics and a high risk of local recurrence. Histologically they belong to the family of fibromatose tumours and appear as interwoven bundles of monomorphic spindle cells with varying amounts of collagen. Differentiation between a low grade fibrosarcoma and a desmoid tumour is sometimes difficult but the latter displays normal mitosis, monomorphic cells and no metastasis. Due to the infiltrative growth characteristic of desmoid tumours they may be more extended than the clinically palpable tumour. Therefore wide excision margins are recommended upon operation, although experimental evidence for lower recurrence rates following wide resection margins is not yet apparent [3].
Although various medical procedures have been introduced for the treatment of the lesions such as anti-oestrogens, steroids, chemotherapeutic agents and radiation, surgery is the treatment of choice. In this patient, both desmoid tumours occurred at the insertion sites of the dialysis catheters. This may have been due to the surgical procedure for the placement of the peritoneal catheter and to the chronic fibrous reaction in the rectus muscle sheath caused by the silastic catheter, which is not an inert material. Gonzáles-Darder et al. [4] reported a patient with a DandyWalker malformation developing a desmoid tumour around the distal tubing of a cerebrospinal fluid shunt. Jewett and Mead [5] quoted a case of desmoid tumour arising in a silicone breast implant. In both reports the catheter or the implants, respectively, were still in place, with tumour formation around the foreign material. Considering these reports, we conclude that the diagnosis of a desmoid tumour should be taken into consideration when a mass is arising in an area where silicon material has been implanted or is still in place.
Notes
Email: julianmall{at}hotmail.com
References