Intraductal papilloma is a benign tumor found within breast ducts. The abnormal proliferation of ductal epithelial cells causes the growth. A solitary intraductal papilloma is usually found centrally posterior to the nipple affecting the central duct. Multiple intraductal papillomas are located peripherally, found in any breast quadrant affecting the peripheral ducts. Women of all ages can develop intraductal papillomas. The exact cause of the condition is unknown, but predisposing risk factors include gender, contraceptive use, lifetime estrogen exposure, and the patient's reproductive history.
Patients with symptoms often present with spontaneous bloody or clear nipple discharge. An intraductal papilloma may be occasionally palpable. However, most patients with an intraductal papilloma are asymptomatic. Small intraductal papillomas often will show no signs or symptoms. Working up an intraductal papilloma is imperative. Although not a carcinoma, it is classified as a high-risk precursor lesion due to its association and potential progression to atypia, ductal carcinoma in situ (DCIS), and carcinoma. Surgical excision with complete tumor removal is the recommended treatment. Intraductal papilloma removal is curative with a recurrence rate of less than 10%.
Intraductal papilloma is classified as a high-risk precursor lesion. This classification is due to its association and potential progression to atypia, DCIS, and carcinoma. The exact cause of intraductal papilloma is not known. However, predisposing risk factors leading to the development of an intraductal papilloma include hormonal influence, fertility, and diet.
Intraductal papilloma can occur in women of all ages. There is a higher prevalence in young and middle-aged women. The age of presentation is mostly between 30 and 50 years without a specific bias for any racial or ethnic group. Intraductal papilloma represents approximately 10% of all benign breast tumors. Although its exact cause is unknown, there are associated predisposing risk factors. These risk factors include gender, with women having a higher risk than men, obesity, alcohol consumption, contraceptive use, lifetime estrogen exposure, physical inactivity, and the patient's reproductive history.
Intraductal papilloma is associated with atypical ductal hyperplasia, a papillary subtype of DCIS, and/or invasive carcinoma. Associated abnormalities were more frequent with peripheral type intraductal papilloma than central type intraductal papilloma. Intraductal papilloma often appears as a mural soft tissue cauliflower-like mass situated within a dilated duct. The duct may contain either clear or bloody fluid. On microscopy, there will be dilated ducts surrounding the tumor. The papilloma will contain epithelial fronds with a fibrovascular stroma. Cell types include cuboidal and columnar type epithelial cells with an intervening myoepithelial cell layer. Cellular atypia or hemorrhagic infarction seen within the mass may mimic carcinoma.
Typical presentation includes spontaneous bloody or clear nipple discharge. Occasionally, a painless lump may be clinically palpable. Changes to the skin include dimpling, irritation, redness, scaling, peeling, and/or puckering. Inversion of the nipple may occur. Intraductal papilloma of the breast can be solitary in one breast or multiple in one or both breasts.
Intraductal papilloma is often mammographically occult. However, if seen mammographically it commonly appears as a round or oval mass with either a well-circumscribed or indistinct margin. It may be associated with grouped amorphous, coarse heterogeneous, and/or punctate calcifications. Under ultrasound, the mass is commonly found near the nipple. The tumor will be in a dilated duct and will often show flow on color or power Doppler. If bleeding has occurred, an ultrasound can reveal associated echogenic fluid or fluid-debris level. On galactography, intraductal papilloma appears as an intraluminal filling defect with ductal dilation leading up to the mass with an abrupt ductal cutoff. MRI is not commonly employed for the diagnosis of intraductal papilloma as their findings are nonspecific. MRI findings include an enhancing round or ovoid intraductal mass with likely rapid wash-in and wash-out enhancement on kinetic evaluation.
A biopsy of the tumor is definitive in the diagnosis of intraductal papilloma. Examination of the biopsy by a pathologist under microscopy is the ideal standard. There are different types of biopsy methods. These include fine needle aspiration, core needle biopsy, and open tissue biopsy. Core needle biopsy is most commonly used. It uses a wide needle to obtain an adequate tissue sample for pathologic analysis. Fine needle aspiration is less preferred as it uses a thinner needle, creating the chance for insufficient sampling. Open tissue biopsy is not preferred as it is a surgical approach. It is more invasive and has a higher likelihood of creating a cosmetic breast deformity.
Treatment of intraductal papilloma involves surgical excision and complete removal of the tumor. The procedure consists of making a skin incision to insert a vacuum-connected probe. The mass will then be vacuumed out. This type of method is called a lumpectomy. This condition has an excellent prognosis if treated with lumpectomy, often with complete removal of the intraductal papilloma.
Differential diagnosis includes atypical papilloma, ductal ectasia with debris, nipple adenoma, fibroadenoma, intraductal epithelial proliferations, and encapsulated papillary carcinoma in situ. Atypical papilloma is typically larger than intraductal papilloma, with a subtle difference on histopathology. Ductal ectasia with debris will show no flow on Doppler assessment. Nipple adenoma is the benign proliferation of ductules in the nipple. Fibroadenoma arises from the terminal ductal lobular unit and is not intraductal in location. Intraductal epithelial proliferation is not a true papillary lesion as it has no fibrovascular core. Encapsulated papillary carcinoma in situ is more irregular in shape and lacks a myoepithelial layer.
Patients have a slightly increased risk of developing breast cancer and are twice as likely to develop it than the relative general population. Central papillomas produce a lower risk when compared to peripheral papillomas. Predisposing risk factors will contribute to intraductal papilloma development. Complete surgical excision is curative with less than a 10% recurrence rate. The prognosis is excellent when treated with surgical removal and complete excision of the tumor.
No significant complications are involved with intraductal papilloma. A few patients may experience emotional stress due to concern for malignancy. Skin changes associated with intraductal papilloma include nipple retraction and/or dimpling which may result in patient cosmetic concern. Fine needle aspiration and core needle biopsies often do not cause significant breast deformity.
There is no way to prevent intraductal papilloma. However, healthcare professionals should educate the patient about breast cancer and other breast lesions. The nurse is in a prime position to teach the patient about breast exams, which may help detect any breast abnormalities early. In addition, the nurse should encourage women to undergo screening mammograms after the age of 45. At the same time, the patient should be encouraged to discontinue smoking, maintain a healthy weight, eat a healthy diet and follow up with regular breast exams by the primary care provider.
For women who undergo excision of the intraductal papilloma, the outcomes are excellent. However, in the long run, these women do have a slightly increased risk of developing breast cancer compared to the general population. The risk is slightly higher when the papilloma is located in the periphery compared to the centrally located papillomas. Thus, all women should be encouraged to undergo screening mammograms.