BREAST CYTOPATHOLOGY

Hamartoma 83
Hamartoma
Hamartoma is a rare tumorlike growth of mature breast tissue
lacking structural organization, originally described by Pryn
in 1928. Breast hamartoma is considered a dysgenetic rather
than a neoplastic disorder. Association with other dysgenetic
disorders (such as Cowden syndrome) has been described.
Clinical Features
• Lesions are well-circumscribed, benign, and composed of
fat, glandular tissue, and fibrous connective tissue.
• The majority occur in women who are premenopausal.
• Two variants of hamartoma of the breast have been
described: (1) adenolipoma, which is composed of mature
adipose tissue with varying amounts of normal breast
tissue; and (2) chondrolipoma, which has mature adipose
tissue admixed with hyaline cartilage.
Cytomorphologic Characteristics
• Moderate cellularity
• Irregularly branching sheets of cohesive ductal epithelium
• Intact lobular units
• Lack of cytologic atypia and lack of cellular dispersal
• Abundant naked bipolar nuclei, few stromal fragments,
multinucleated histiocytes, rare apocrine cells
• Adipose tissue fragments
Pitfalls and Differential Diagnosis
• Normal breast tissue
• Fibroadenoma
• Fibrocystic changes
Selected Reading
Dawson AE, Mulford DK: Benign versus malignant papillary neoplasms
of the breast. diagnostic clues in fine needle aspiration
cytology. Acta Cytol 1994, 38:23–28.