Merkel cell carcinoma: An entity to know

A 84-year-old man consulted his family doctor for evaluation of a rapidly expanding nodule on his leg that had been growing over last 6 months. He reported no recent trauma to the area and had no systemic symptoms. He has a personal history of dyslipidemia, type 2 diabetes mellitus, hypertension, chronic kidney disease, gout and chronic obstructive pulmonary disease. Physical examination revealed a firm, painless, ulcerate, flesh-colored nodular lesion sized 4.5 cm, and some clustered nodules with a dome-shaped appearance and pink-red surface on the posterior face of the right leg (Fig. 1). No other lesions were identified and no lymphadenopathy was detected.

Figure 1.

Skin lesion on the posterior face of the right leg identified in first medical visit that triggered suspicion of skin tumor.

In this context, a biopsy was performed and a diagnosis of Merkel cell carcinoma was made. Immunohistochemical study showed was strong expression of Ber-Ep4 and absence of expression of S100 and SOX10. The patient was referred to the oncology department for staging and management. The patient had a metastatic disease. In follow-up visit, after one month, patient was waiting for palliative chemotherapy and physical examination revealed expanded nodular lesion, now with size of 7 cm.

Merkel cell carcinoma is a rare, aggressive, cutaneous neuroendocrine tumor that predominantly affects older adults with light skin types.¹ Clinically, it presents as a rapidly enlarging nodule, usually located on sun-exposed skin and may closely mimic benign lesions. Clinical warning signs summarized in the acronym AEIOU (asymptomatic lesion, expanding rapidly, immunosuppression, age older than 50 years, UV-exposed skin).²

We present this case to increase awareness of the health professionals on this kind of skin tumor and remind high risk population, avoiding delay in diagnosis and treatment.

Ethical considerations

Written informed consent was obtained from the patient as well as the subjects’ privacy has been respected. The protocols and procedures of the institutional center related with the patient's data publication have been followed.

Funding

No funding sources.

Conflict of interest

None.