P2.K213: A Rare Encounter: Intraductal Papilloma Presenting as a Breast Mass in an 8-Month-Old Male

Introduction: In pediatrics, intraductal papilloma is a rare disease with an exceptionally low incidence among males, particularly during infancy and early childhood. While commonly presenting as bloody nipple discharge, it may also manifest as a discrete breast mass. Historically perceived as a benign lesion, recent attention has been directed towards its potential for malignant transformation.

Case Description: 8-month-old male with a breast swelling noticed by his parents one day prior to a visit with their pediatrician. The swelling appeared well-circumscribed, mobile, rubbery, approximately 10x10 mm in diameter, and exhibited a greenish hue. Ultrasound revealed a retroareolar right breast multiseptated complex cyst-like structure with tubular anechoic formations within, measuring 21x20x6 mm. The findings were suggestive of duct ectasia, classified as Bi-Rads Category 3 with a benign probability. Surgical excision of the mass was underwent due to concerns of an increase in size. Grossly the resected mass measured 15x15x12 mm, revealing a cystic space filled with dark green thick mucus. Pathology revealed dilated cystic ducts and an intraductal papilloma with microcalcifications.

Discussion: Breast masses rarely occur in the pediatric population, particularly in males, and their occurrence can cause family distress. These masses affect approximately 3% of the pediatric population. Pediatric breast masses are usually benign, though there have been reported cases of malignancies. When assessing a palpable breast mass in males, potential diagnoses encompass breast buds, gynecomastia, lipomas, mammary duct ectasia, fibroadenomas, cystosarcoma phyllodes, and on rare occasions, breast cancer. Intraductal papillomas, represent a rare occurrence that have received limited study and lack established guidelines of practice. Intraductal papilloma, a benign lesion, may manifest at any age but is most prevalent among women aged between 35 and 55 years. These lesions are benign and arise from the proliferation of ductal cells. Typically, they present with nipple discharge, which can be sanguineous or serosanguineous. Ductogram is considered the gold standard for diagnosis but ultrasound is more practical in the pediatric population. Management typically involves local excision. Diagnosing breast masses pose a challenge whether to excise or observe based on ultrasound. Unlike adults where BIRAD scoring system is utilized to categorize the likelihood of malignancy, use is less common in pediatrics due to the rarity of malignancy. Although intraductal papilloma is typically regarded as a benign diagnosis, evidence suggests it may represent a premalignant condition. Genetic factors such as chromosome 16p13 and –q21 tumor suppressor gene mutations, as well as loss of heterozygosity and TP53 deletions at the 16q23 locus, may predispose affected individuals to increased risk of malignant transformation.

Conclusion: This case underscores the significance of considering ultrasound findings when evaluating unilateral breast swellings in infants, considering intraductal papilloma as a differential. Additionally, it emphasizes the importance of providing families with clear return precautions when observing breast swellings.