Sentinel Lymph Node Biopsy in Recessive Dystrophic Epidermolysis Bullosa and Squamous Cell Carcinoma

Squamous cell carcinoma (SCC) is the most common cause of death in patients with recessive dystrophic epidermolysis bullosa (RDEB).¹ In the Hallopeau-Siemens type, the cumulative risk is 76.5% by age 60 years.² The sentinel lymph node (SLN) biopsy technique enables the early detection of micrometastasis not only in melanoma but also in other skin malignancies such as high-risk SCC or Merkel cell carcinoma.³

In April 2003, a 30-year-old man with Hallopeau-Siemens RDEB since birth complained of an excrescent, fleshy, and ulcerated mass on the right heel, which had been evolving for 13 months in the area of a nonhealing wound. The tumor measured 9 × 7 cm (Figure, A). Biopsy findings confirmed the diagnosis of a well-differentiated and infiltrated SCC. Magnetic resonance imaging demonstrated invasion of the calcaneus and of the Achilles tendon. Computed tomography findings of the thorax, abdomen and pelvis were normal; no locoregional adenopathies were detected.

The tumor was excised with a 2-cm safety margin. In addition, the posterior tuberosity of the calcaneus and the distal third of the Achilles tendon were also excised (Figure, B). We applied a topical treatment of hyaluronic acid gel for 40 days. By this time enough granulation tissue had grown, and abdominal skin was grafted onto the wound (Figure, C).

Owing to the aggressive potential of the tumor, the patient underwent preoperative lymphoscintigraphy with technetium Tc 99, and during the operation an SLN biopsy was performed. The analysis of specimens from 2 big SLNs showed unspecific inflammation. Twelve months after tumor excision, the patient remains free of illness.

An SCC is considered high risk when any of the following factors is present: size larger than 2 cm; depth of 4 mm; poor to moderate differentiation; anatomic location on the lip or ear; vascular, skeletal, muscular, or neural invasion; and/or local recurrence. Immunosupressed patients and those who have undergone transplantation or irradiation also constitute a risk group.⁴ Patients with DEB, especially RDEB, should be included in this group because often their tumors develop very aggressively, with local recurrences and early metastasis.¹

At present, there are very few series that verify the benefits of SLN biopsy in SCC of the skin, although the most recent studies demonstrate that this technique is useful in detecting subclinical metastasis in patients with high-risk cutaneous SCC and a clinical N0 status.³ There is only 1 reported case of SLN in a patient with SCC and RDEB, and, as in our case, lymph node micrometastasis was not detected.⁵

In light of the above, we would suggest that an SLN biopsy be performed on patients with SCC and RDEB, although more cases and studies are needed to confirm this. However, for these patients, this low-morbidity technique can be useful for staging and prognosis, and it allows for treatment with an earlier and less aggressive adjuvant therapy.

Correspondence: Dr Perez-Naranjo, C/Nervion, 26 Urb Las Pilas, 41907, Valencina de la Concepcion, Sevilla, España (laraperez@yahoo.com or lara@aedv.es).

Financial Disclosure: None.