Medium Power: DQ Stain
Ghost cells
High power: DQ Stain
Ghost cells
Medium power: Pap stain
Small fragments of basaloid cells associated with keratin debris and scattered ghost cells
High power: Pap stain
Basaloid cell component seen with relatively high nuclear to cytoplasmic ratios. The nuclei have smooth contours and evenly dispersed chromatin. Ghost cells can also be appreciated in this field of view.
High power: Pap stain
Giant cells are often present, a likely response to keratin material present within the lesion
Features
• Also known as calcifying epithelioma of Malherbe
• Most commonly found in head/neck and upper extremities
• Majority seen in children/teenagers
• Pitfall: Squamous cell carcinoma, make sure the clinical and radiographic information correlates
• Typically cellular
• Cohesive fragments of basaloid type cells and clumps of keratin
• Basaloid cells with relatively high nuclear to cytoplasmic ratios
• Keratin debris
• Ghost cells (eosinophilic cells devoid of nuclear staining)
• Multinucleated giant cells commonly seen
• Nucelar contours are typically smooth
• Chromatin is evenly dispersed
• Nucleoli visible to prominent
• Ghost cells: lack nuclear staining
• Clumps of keratin debris
• May have calcification and metaplastic bone
• Lemos MM et al: Fine-needle aspiration features of pilomatrixoma. Cancer. 93(4):252-6, 2001
• Ieni A et al: Limits of fine-needle aspiration cytology in diagnosing pilomatrixoma: a series of 25 cases with clinico-pathologic correlations. Indian J Dermatol. 57(2):152-5, 2012