Tubular Adenoma of the Breast: A Clinicopathologic Study of a Series of 9 Cases

Abstract

Tubular adenoma of the breast is one of the most rare benign neoplasms, accounting for only 0.13% to 1.7% of all breast benign tumors. Little is known about this rare neoplasm as the current literature offers only some case reports or a few number of small series. The aim of our study is to provide some clinicopathologic features of the breast tubular adenoma. We retrospectively analyzed at our department of pathology all cases of breast tubular adenomas confirmed by immunohistochemistry over a period of 9 years (2009-2017). Nine cases of breast tubular adenoma have been recorded, with an average age of 31.44 years. Five tumors were located at the right side (55.55%), and most cases had suspicious aspects on imaging techniques (6 cases out of 9). The diagnosis has been made on 5 resected specimens (lumpectomy) and on 4 core needle biopsies. The tumor size ranged from 0.9 to 7 cm (mean size of 3.08 cm) and had well-circumscribed margins with elastic consistency. The histopathologic analysis showed a typical pattern of proliferating round and uniform tubules lined by regular epithelial cells surrounded by myoepithelial cells, packed in a small amount of stroma, highlighted by CD34 immunostaining. Tubular adenoma is a rare breast benign neoplasm of young premenopausal women. The radiologic aspects are often worrisome and only the histopathologic analysis can achieve the correct definitive diagnosis by excluding all potential differential diagnoses.

Breast tubular adenoma

“…2 Moreover, the CD34 immunohistochemical staining highlighted the inconspicuous small amount of the stromal component, characteristically found in tubular adenoma. 2…”

“…4 Tubular adenomas mimic fibroadenomas in their radiologic appearance as they both appear as noncalcified well circumscribed lesions on ultrasound. 2 Histologically, the tumor is characterized by the presence of proliferating round and uniform tubules lined by regular epithelial cells surrounded by myoepithelial cells, packed in a small amount of stroma, highlighted by CD34 immunostaining, and in certain areas of the tumor, the lumen of the tubules contain eosinophilic amorphous materials. 2 Moreover, the CD34 immunohistochemical staining highlighted the inconspicuous small amount of the stromal component, characteristically found in tubular adenoma.…”

“…Tubular adenoma is a benign neoplasm of epithelial origin arising from the breast accounting for 0.13%-1.7% of all benign breast neoplasms. 1,2 Tubular adenomas are commonly found in young women and rarely found before menarche or after menopause. 2,3 Tubular adenomas were first described histologically by Persaus et al in 1968.…”

“…1,2 Tubular adenomas are commonly found in young women and rarely found before menarche or after menopause. 2,3 Tubular adenomas were first described histologically by Persaus et al in 1968. However, in 1983, Morros et al studied tubular adenomas by cytology and light and electron microscopy, and only few cases were reported in the literature.…”

“…4 It is difficult to diagnose tubular adenoma pre-operatively depending on clinical and radiologic findings as the final diagnosis is only based on the histopathologic findings, which is a small amount of fibrous stroma containing proliferative tubular structures. 1,2…”