Diagnosis: Pilomatricoma
Description: Bullous lesion with erythematous overlying skin.
Morphology: Unusual shapes
Site: Arm,upper
Sex: F
Age: 18
Type: Clinical
Submitted By: Nameer Al-Sudany
Differential DiagnosisHistory:
Pilomatricoma (Pilomatrixoma or Calcifying Epithelioma of Malherbe) is a benign tumour derived from the hair matrix cells. It usually presents as an asymptomatic, solitary, deep seated, firm subcutaneous nodule with normal or pinkish above skin. The overlying skin on stretching produces the “tent sign” with multiple facets and angles. Commonest sites are the face, neck or arms; however, the scalp, trunk and lower extremities may be involved. At times, pilomatricoma may have a bullous appearance as in the current case of a female presented with a large bullous lesion with positive transillumination on the upper arm of six months duration. The tumour has been excised totally and sent for HP which revealed an encapsulated mass composed of solid masses of basophilic cells and eosinophilic shadow cells.