Merkel Cell Carcinoma of the Eyelid With a Positive Sentinel Node

Merkel cell carcinoma (MCC) of the eyelid is a rare but aggressive malignancy that metastasizes early to regional lymph nodes.¹ Most clinical series suggest a rate of regional nodal involvement between 21% and 66%.^2-4 Early detection of occult regional nodal disease may allow for early institution of adjuvant therapy. We describe a patient with MCC of the eyelid with clinically uninvolved nodes who underwent sentinel lymph node (SLN) biopsy soon after the diagnosis of his primary tumor. An SLN was identified and showed histologic evidence of MCC. To our knowledge, this is the first reported case of a positive SLN secondary to MCC of the eyelid.

A 61-year-old man noted an erythematous lesion on his left upper eyelid in May 2001. He went to his local ophthalmologist, who excised the lesion but did not examine it histologically. In June 2001, the lesion recurred. The recurrent lesion measured approximately 12 mm in diameter. The patient sought an opinion from an oculoplastic surgeon, who performed a wide local excision of the lesion with frozen section control of the margins. The histologic findings were consistent with MCC of the eyelid (Figure 1 A and Figure 1 B). Sentinel lymph node biopsy was scheduled but had to be delayed because the patient developed acute appendicitis, necessitating an emergent appendectomy. In July 2001, the patient underwent SLN biopsy using a combination of isosulfan blue dye and Tc 99m–labeled sulfur colloid. The afferent lymphatics were identified before surgery using radionucleotide imaging. Intraoperatively, a combination of radiolabeled sulfur colloid and isosulfan blue dye was used to identify SLNs. An area of focal radioactive uptake was identified in the left preauricular (parotid) area using a handheld gamma probe and was marked on the skin. The corresponding SLN was removed and analyzed histologically using serial sectioning and immunohistochemical staining. The node was found to be positive for MCC (Figure 1 C and Figure 1 D). The patient subsequently underwent a total parotidectomy and completion neck dissection. The parotidectomy specimen included 1 additional lymph node that was positive for MCC. The node was located in the deep lobe of the left parotid gland and showed extracapsular extension.

In September 2001, the patient self-referred to the University of Texas M. D. Anderson Cancer Center (Houston) for further management of his tumor. At this time, he had a well-healed area of excision in his left upper eyelid, and the area of the neck dissection and parotidectomy had healed. Findings on the patient's ophthalmologic examination were essentially normal, with no clinical evidence of local or regional recurrence of cancer. His systemic workup, including computed tomography of the head and neck, abdomen, and pelvis, chest radiography, and magnetic resonance imaging of the brain, was negative for tumor. A multidisciplinary team, including an ophthalmic surgeon, a head and neck surgeon, a head and neck medical oncologist, and a head and neck radiation oncologist examined the patient and recommended that he receive adjuvant external beam radiation therapy to the eyelid, parotid nodes, and deeper cervical nodes. The team also recommended that the patient be given 4 courses of chemotherapy with etoposide and cisplatin after the completion of radiation therapy.

In patients with MCC, the regional lymph nodes are thought to be the most common and earliest site of metastasis; thus, adjuvant treatment of the regional lymph nodes has been advocated by many investigators.^3,5,6 Jean et al⁷ successfully identified 1 or more SLNs in 19 of 20 patients with stage I MCC who underwent SLN biopsy at the time of initial wide local excision. The authors found that 5 (26%) of the 19 patients in whom SLNs were successfully identified had at least 1 histologically positive SLN. Other isolated cases of SLN biopsy for MCC have also been reported.⁸

Merkel cell carcinoma of the eyelid is thought to account for 10% of all cases of MCC.² In a review of all previously reported cases of MCC of the eyelid, Kivela and Tarkkatnen² concluded that up to two thirds of patients eventually develop regional nodal involvement. This rate is higher than the rate reported in most single series of MCC of the eyelid. In the largest single series to date, Peters et al³ reported clinical regional nodal involvement in 3 (21%) of their 14 patients.

Sentinel lymph node biopsy allows for early detection of occult regional lymph node metastasis and thus, more accurate staging of MCC and the possible institution of early adjuvant therapy. Although SLN biopsy has recently become the standard of care for most solid tumors throughout the body, SLN biopsy in the periocular area remains investigational.⁹ To our knowledge, there have been only 2 previous reports of application of SLN biopsy techniques for conjunctival and periocular tumors.^10,11 We described successful identification of SLNs in a single patient with a conjunctival melanoma, using a combination of radiolabeled sulfur colloid and isosulfan blue dye.¹⁰ Wilson et al¹¹ attempted identification of SLNs in 5 patients with periocular tumors (2 melanomas, 2 meibomian gland carcinomas, and 1 case of mucoepidermoid carcinoma), using radiolabeled sulfur colloid alone. These authors reported successful identification of at least 1 SLN in 5 patients, although the technique used in the latter report is believed by some investigators not likely to lead to the correct identification of the sentinel nodes.¹² Neither of the 2 previous reports of SLN biopsy for conjunctival and periocular tumors found a positive SLN. To our knowledge, ours is the first reported case in which an SLN was successfully identified in a patient with an eyelid tumor and was also found to be histologically positive.

This case underscores the feasability and potential usefulness of SLN biopsy as a method for identifying occult metastatic disease from an MCC of the eyelid. Early detection of micrometastasis in the regional nodes allows for immediate institution of adjuvant therapy, which may include completion neck dissection, external beam radiation therapy, and adjuvant chemotherapy.

Corresponding author and reprints: Bita Esmaeli, MD, Ophthalmology Section, Department of Plastic Surgery, Box 443, M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030 (e-mail: besmaeli@mdanderson.org).