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 work-up, 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.


CONCLUSIONS
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.
Department of Otolaryngology - Head and Neck Surgery, National University Health System, Singapore. Electronic address: joshua_tay@nuhs.edu.sg.
Joshua K
JK
Tay
Department of Pathology, National University Health System, Singapore.
Min En
ME
Nga
Department of Otolaryngology - Head and Neck Surgery, National University Health System, Singapore.
Kwok Seng
KS
Loh
D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D019298:Glucose-6-Phosphate / Q000031:analogs & derivatives; D006201:Hair Diseases / Q000175:diagnosis*; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008875:Middle Aged; D018296:Pilomatrixoma / Q000175:diagnosis*; D049268:Positron-Emission Tomography; D012878:Skin Neoplasms / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed
C047515:2-fluoro-2-deoxyglucose-6-phosphate; D019298:Glucose-6-Phosphate