BMC Cancer 2005, 5:106 http://www.biomedcentral.com/1471-2407/5/106 FCilginuicrael a1ppearance of second recurrence of Merkel tumor on lower lip Clinical appearance of second recurrence of Merkel tumor on lower lip. Past medical history revealed that 8 years earlier, the patient had been diagnosed as having chronic lym- phocytic leukemia (CLL), (nodular and intermediate type), but he didn't receive any treatment. CT scan of the head and neck area, showed a soft tissue lobular mass, 3 cm in diameter, on the lower lip, with a possible exten- sion to the mandible. The past medical history of CLL with the recent occurence of MCC posed a problem in the differential diagnosis of the patient's lymphadenopathy. A W-excision (4 × 3.5 × 1 cm) of the lip lesion was per- formed, with an open biopsy of one submandibular lymph node. Histopathology, confirmed recurrence of MCC. An undif- ferentiated small cell carcinoma with hyaluronated stroma was identified. The cells arranged in nodules or rosettes, had dense nuclear chromatin, with mitoses and nuclear debris which are regular features of MCC (Fig. 2, 3). Immunoistochemical procedures showed Neuron Spe- cific Enolase (NSE) positivity, while antibodies for Epithe- lial Membrane Antigen (EMA) and Chromogranin were negative. The excision was described as complete. The submandibular lymph node was positive for malignacy but was associated with the CLL (non Hodgkin's, B cell small lymhocytic lymphoma). There was no evidence of metastatic infiltration by MCC and this was confirmed immunoistochemically with the positive expression of CD5 and CD20 antibody and negative expression of CD10 antibody and NSE. Due to the age of the patient, chemotherapy was not considered. A month later, a new CT scan of the head and neck, depicted a soft tissue mass, consistent with recurrence of MCC, between the left angle of the mandible and the hyoid bone. Multiple enlarged superficial and deep cervi- cal lymph nodes were present. Fine needle aspiration (FNA) of the submandibular swelling was performed and Page 3 of 6 (page number not for citation purposes)