BREAST CYTOPATHOLOGY

74 3. Benign and Borderline Tumors
• Ductal/nipple adenomas occur in the fifth to sixth decades
of life and most commonly involve small to mid-sized ducts
and less commonly arise in the subareolar region.
• Ductal/nipple adenomas are rarely seen in men.
Cytomorphologic Features
• Limited cytopathologic experience because of the uncommon
occurrence of this lesion
• Variable cellularity, more often low
• Cohesive ductal-type epithelial fragments, tubular or
fingerlike papillary morphology
• Presence of myoepithelial cells (only in association with
epithelial fragments and not in smear background)
Pitfalls and Differential Diagnosis
• Hypercellularity may lead to an overcall of atypical or,
rarely, malignant diagnosis. Presence of somewhat cohesive
fragments and well-identified myoepithelial cells is
helpful.
Granular Cell Tumor
Approximately 6%–8% of all granular cell tumors are
encountered in the breast. Clinically and radiologically, granular
cell tumor closely mimics primary breast carcinoma
(hard spiculated mass often fixed to the overlying skin).
Therefore, an accurate FNA diagnosis is extremely critical
for disease management.
Clinical Features
• Average age at presentation is 30 years.
• Most tumors measure less than 2 cm.
• Tumors behave in a benign fashion with local excision
curative in most cases.