A rare case of fibroadenoma in a tubular adenoma of the breast.

We report herein a case of a 31 year old housewife who underwent an excisional biopsy for a well-circumscribed lump in her breast. The lump contained 2 histological patterns, namely, fibroadenoma and tubular adenoma. These patterns had no transitional zone, were distinct and changed abruptly. This case was histologically diagnosed as "a fibroadenoma in tubular adenoma of the breast, benign", with no other such case ever having been reported in Japan. The histological findings of this case, convinced us that tubular adenoma is closely related to fibroadenoma.