Pilomatrixoma in an infant: diagnostic challenges of fine-needle aspiration.

Fine-needle aspiration biopsy (FNAB) is a well-recognized minimally invasive tool in the diagnosis of neoplasia of various organ systems. Several reports in the literature suggest that FNAB can be an accurate method for the preoperative diagnosis and treatment planning. We describe a case to caution the interpretation from a FNAB that contains suboptimal contents (basaloid cells only) and highlight a clinical-pathologic-based algorithm that can provide the appropriate management for the patient when the cytopathologic diagnosis does not fit the clinical impression.