Merkel cell carcinoma (MCC) is a rare and potentially aggressive neuroendocrine tumour. The authors describe a unique presentation of a 4.5 cm wide MCC of the upper lid in a 73-year-old female. After total upper lid resection, immediate reconstruction was achieved by a full-thickness lower-lid transposition flap based on the lower lateral palpebral artery. At the 3 year follow-up the patient is free from disease and the reconstructive result is satisfactory both functionally and aesthetically.
Merkel cells were discovered by Friederich Merkel in 1875 and described as clear, round, large cells located in the basal layer of the epidermis. In 1975 Toker et al. first identified a rare aggressive neuroendocrine tumour derived from those cells, the Merkel cell carcinoma (MCC) which is considered a malignancy of the amine precursor uptake and decarboxylation (APUD) system. Merkel cells are found in the highest concentration in the acral skin, both glabrous and hairy, and in mucous membranes. Despite being functionally related to touch receptors for mechanical stimuli, their exact function and origin remain unclear.
Much like the origin of the Merkel cell itself, the aetiology of MCC is controversial. Although Merkel cells are found in the epidermis, MCC arises predominantly in the dermis and rapidly invades the subcutaneous tissue. Exposure to ultraviolet radiation is thought to play a role in the development of this type of tumour and, more recently, polyomavirus infection has been associated with the presentation of MCC. Elderly people or patients with compromised immune status, such as those affected by chronic lymphocytic leukaemia, more frequently develop MCC. Females are affected approximately twice as often as males.
The eyelid location accounts for 5–10% of all MCCs. In 20–60% of affected patients, preauricular and neck lymph nodes are positive at presentation and locoregional spread increases from 55% to 79% during the course of the disease. Distant metastases (skin, bone, brain, liver and lung) appear in 70% of cases, usually within 2 years and 5-year survival has been reported to be 30–64%.
The clinical management of MCC is often discussed but when restricting the data to eyelid MCCs, few cases have been described. Eyelid tumours may differ from those located elsewhere, for anatomical reasons and their management, and standard treatment regimens have not been defined.
In this paper, the authors present a new surgical approach for managing a 4.5 cm MCC of the upper eyelid in a 73-year-old woman.
The patient presented to the authors’ institution 2 months after presentation of a nodular lesion of the left upper eyelid ( Fig. 1 ). Her clinical history was negative with respect to previous malignancy, immunosuppression and cardiovascular disease. She had a left breast lumpectomy at the age of 42 years after being diagnosed with a fibroadenoma.
At the time of diagnosis the lesion had the appearance of a solid, exophytic mass, over 4.5 cm in diameter. At clinical examination the patient had no evidence of lymph node involvement. Preoperative examination, including orbit, neck, chest and total body computed tomography (CT) scan was negative.
Biopsy samples of the mucocutaneous margin and the deep layer were analysed. The diagnosis of a neuroendocrine small cell carcinoma compatible with MCC was suggested on the basis of cytological features identified in haematoxylin–eosin stained sections. Tumour cells with scanty cytoplasm, round and vesicular nuclei with granular chromatin and multiple nucleoli were present in all samples ( Fig. 2 ).
Further immunohistochemical investigations revealed positivity for MNF-116, cytokeratin 20 (distinct perinuclear dot like quality), chromogranin, neurofilament protein and synaptophysin ( Fig. 3 ). On those findings the diagnosis of MCC was confirmed. Reaction for cytokeratin 7 was negative. No lymph node involvement was observed.
Initially the patient underwent a total excision of the lesion and of the full upper eyelid according to radical oncological criteria; three intraoperative biopsy samples of the lateral, medial and superior margins were taken for frozen sections and interpreted as demonstrating no evidence of tumour. A full thickness lower eyelid pentagonal flap was raised following the preoperative planning and superiorly transposed to reconstruct the upper lid ( Fig. 4 ). This flap is to be considered a technical modification of the previously described ‘switch flap’. Briefly, after performing a full thickness pentagonal incision of the middle-lateral portion of the lower lid, the pedicle (inferior lateral palpebral artery connecting to the medial (Malar) branch of the transverse artery of the face and to the anterior branch of the superficial temporal artery) was identified about 1 cm from the lateral orbital rim just above the orbicularis oculi muscle. The pedicle was carefully isolated and was dissected laterally about 1.5–2 cm, in order to allow for a comfortable transposition to the upper lid defect. This lateral dissection was carried out carefully to preserve the anterior branch of the superficial temporal artery and the malar branch of the transverse artery of the face, providing vasculature to the inferior lateral palpebral artery. During the flap transposition to the upper eyelid defect, the lower palpebral rim containing lashes was resected, and the cruent margin sutured to the proximal upper lid stump. The flap was thus tailored and re-shaped conservatively to reproduce upper lid morphology.