Pilomatricoma of the cheek: A benign tumor mimicking metastatic squamous cell carcinoma on FDG PET/CT

Background: Pilomatricomas are benign skin tumors originating from hair matrix cells in the dermal layer of the skin, especially in the head and neck region. They may mimick malignant lesions on fine-needle aspirate cytology. Methods: This is a case report of a pilomatricoma of the cheek which was initially diagnosed as squamous cell carcinoma on fine-needle aspirate cytology. As part of the staging workup, a PET/CT scan was performed, revealing a FDG-avid superficial cheek lesion and also an ipsilateral FDG-avid level II cervical lymph node, giving the impression of metastatic squamous cell carcinoma. Results: The cheek lesion, as well as the cervical lymph node was excised. The final histology showed benign pilomatricoma and reactive lymphadenopathy. Conclusion: Pilomatricoma should be considered as an uncommon differential diagnosis for an FDG-avid cutaneous lesion on PET/CT, even in the presence of ipsilateral FDG-avid cervical lymphadenopathy. (C) 2014 Elsevier Inc. All rights reserved.