[Merkel cell carcinoma. Retrospective analysis of 4 cases with special reference to diagnosis, therapy and long-term outcome].

BACKGROUND: Merkel cell carcinoma is an aggressive neuro-endocrine skin tumor with early regional lymph node involvement and early distant metastases. Diagnostic work-up may be difficult because of the low incidence of the tumor. Treatment concepts are individual and long-term-outcome are varying markedly. METHODS: Retrospective analyse of four cases with special regard to the diagnostic, therapeutic approach and the long-term follow-up. RESULTS: In every case diagnosis has only been made histologically. In the first patient, suffering from a tumor on the upper arm, after the tumor removal, local and axillary radiotherapy has been performed. In a second case with an extended tumor on the shank, a palliative tumor-debulking was followed by a chemo- and radiotherapy. The third Patient had a tumor in the gluteal region with involvement of the regional lymph nodes. He was treated by a complete surgical excision and lymphadenectomy followed by a local radiotherapy with subsequent chemotherapy. The fourth patient with tumor on the elbow, without lymph node involvement, refused surgical intervention, therefore she has been treated by radio- and chemotherapy. All patients are respectively 1.2 and 3 years are alive without evidence of recurrence. One patient died after 1.5 year because of tumor relapse. CONCLUSION: Diagnosis of Merkel cell carcinoma is difficult and is established only by in- or excision biopsy of the tumor. If ever possible surgical excision combined with regional lymphadenectomy should be performed. Adjuvant radiotherapy is established, whereas the value of chemotherapy has not yet be defined and might be beneficial only in cases of expansive or disseminated growth. In our series we did encounter the often described metastatic involvement of other organs just in one case.