Introduction Nipple adenomas are rare benign neoplasms that closely mimic malignant disease.  They arise from lactiferous ducts and milk sinuses. A retrospective review of nipple adenomas at our institution from 1992 to 2010 was performed with review of pathology, radiographic studies and clinical histories.
Methods and Results Twelve patients with a nipple adenoma were identified. Mean age at diagnosis was 58.5 years (range 43-76). Ten women (83%) were symptomatic. Symptoms included nipple discharge (58.3%), palpable lesions (50%), and ulcerative skin changes (25%). Workup included mammography (12), ultrasound (8) and magnetic resonance imaging (MRI) (1). The lesion size ranged from 0.4-1.5 cm (mean 0.7 cm). Four patients had complete nipple excision, six had partial nipple excision, one had removal via percutaneous biopsy, and one had a mastectomy for history of breast cancer. With 38.3 months follow-up, 3 women (25%) had a diagnosis of breast cancer prior to or after diagnosis of nipple adenoma, and there has been 1 recurrence of nipple adenoma.
Discussion Nipple adenoma is a rare condition with non-specific presentation. Diagnosis is usually made by complete surgical excision. It is important to differentiate these lesions from malignancy. Although no clear correlation has been shown between nipple adenoma and breast cancer, further investigation is warranted.

Nipple Adenoma

Benzon Dy, MD¹ ∙ Cindy Tortorelli, MD² ∙ Sejal Shah, MD³ ∙ Judy C. Boughey, MD¹

Contact: Judy C. Boughey, MD. E-mail This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Citation: Dy B, Tortorelli C, Shah S, Boughey JC. Nipple adenoma. J Surg Radiol. 2011 Jan 1;2(1). Download PDF J Surg Rad January 2011 A08.pdf 7264 Kb Received: September 5, 2010; Accepted: September 11, 2010; Published: September 12, 2010 Copyright: © 2010 Surgisphere Corporation. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Contents - Introduction - Materials and Methods - Results - Discussion - References

Introduction

Adenomas of the nipple (erosive adenomatosis, papillary adenoma, florid papillomatosis) are rare neoplasms that arise from the lactiferous ducts and milk sinuses. Clinically, they can present as ulcerations, erosions, nipple discharge, palpable masses, or as erythematous growths. Nipple adenomas are considered benign; however, they often prove to be a diagnostic dilemma because their clinical and radiologic appearances may mimic Paget’s disease, low grade well differentiated invasive ductal adenocarcinoma, or lymphoma of the breast.1 Mammography and ultrasound provide important information in the workup. The definitive diagnosis and treatment is complete surgical excision with histologic confirmation.2 We present the clinical presentation, radiographic findings, pathology, treatment, and outcomes of 12 patients with nipple adenoma.

Materials and Methods

Institutional Review Board approval was obtained for a retrospective review of the clinical database to identify all cases of nipple adenoma treated at our institution between 1992 and 2010. Histology slides were reviewed by a breast pathologist to confirm diagnosis of nipple adenoma. Radiological studies and clinical histories were also reviewed.

Results

We identified 12 patients with a confirmed histologic diagnosis of nipple adenoma. Mean age at diagnosis was 58.5 years (range 43-76). Ten women (83%) were symptomatic at the time of diagnosis. Seven patients (58.3%) presented with nipple discharge, 6 patients (50%) had palpable lesions, and 3 patients (25%) had ulcerative skin changes. Other findings included pain, discoloration, crusting, erythema and pruritus. The duration of symptoms ranged from 1 week to 24 months (mean 6.2 months). Preoperative differential diagnosis among breast surgeons and dermatologists included nipple adenoma, Paget’s disease, ductal carcinoma in situ (DCIS), and infiltrating ductal carcinoma.

Two patients were asymptomatic at the time of diagnosis. In one patient, the nipple adenoma was found on screening mammogram and was completely excised by percutaneous biopsy. The second asymptomatic patient had the nipple adenoma incidentally identified on pathologic review after a simple mastectomy. The patient had undergone breast conservation and radiation for an invasive ductal carcinoma two years previously with a poor cosmetic outcome and decided on mastectomy and reconstruction.

Radiologic Imaging

All 12 women had mammography, 8 women had an ultrasound performed in addition to mammography, and 1 had an MRI in addition to mammography and ultrasound. A distinct mass or suspicious calcifications in the nipple were preoperatively identified in 6 patients.

On mammography, the most common finding was calcifications in four patients in the subareolar breast tissue and within the nipple (Figures 1 and 2). Calcifications when they were present were most often pleomorphic (Figure 3). Adenomas can present as masses on mammogram and ultrasound. The nipple masses can have circumscribed, lobulated, or spiculated margins. Lesion size on imaging correlated well with size on histologic examination.

Figures 1 and 2. Magnification mammograms demonstrating pleomorphic calcifications within the left nipple.

Figure 3. Left breast ultrasound demonstrating hyperechoic mass with internal calcifications within the left nipple.

The one case which underwent MRI had both negative sonographic and mammographic studies. Her imaging was performed with contrast and showed focal, intense enhancement within the nipple on T1 weighted images (Figures 4 and 5).

Figures 4 and 5. Sagittal and axial breast MRI post contrast T1 weighted images demonstrating marked focal uptake within the right nipple.

Treatment

One patient had percutaneous biopsy for diagnostic purposes in which the adenoma was completely removed and did not undergo further intervention. Eleven patients underwent surgical excision for diagnosis as well as therapeutic management. Four patients had complete excision of their nipple, six had partial nipple excision with a focus of the involved duct, and one woman had mastectomy. On mastectomy, incidental finding of nipple adenoma in permanent sectioning of the nipple was found. One woman with partial nipple excision also underwent wide local excision of a separate biopsy site due to a synchronous DCIS lesion.

Pathology

Pathologic size of the nipple adenoma ranged from 0.4-1.5 cm (mean 0.7 cm). In general, these lesions are grossly firm and ill-defined nodules and are characterized by proliferating ductal structures lined by columnar epithelium. Apical intraluminal projections are commonly found.

In our series, microscopic examination revealed relatively well-demarcated proliferation of benign glands and ducts with an intact myoepithelial cell layer within a fibrotic stroma (Figure 6). Most cases showed expansion of glands by ductal hyperplasia of usual type. One case showed nipple adenoma with focal atypical ductal hyperplasia. None of the cases showed in situ or invasive malignancy arising within a nipple adenoma. In one of the cases, however, a concurrent DCIS was identified in the breast parenchyma adjacent to the nipple adenoma. Because there are a myriad of clinical presentations for nipple adenoma, these key histologic features are essential to diagnosis.

Figures 6 and 7. Nipple adenoma with proliferation of benign ducts and glands within a fibrotic stroma (Figure 6 - H&E x40) with intact myoepithelial cells (Figure 7, facing page, H&E x100).

Outcome

Three women (25%) have had a diagnosis of DCIS or invasive ductal carcinoma either before or after discovery of their nipple adenoma. One woman had a wide local excision of invasive ductal carcinoma and two years later had incidental discovery of her nipple adenoma during mastectomy with breast reconstructive surgery. Another woman subsequently developed ipsilateral DCIS and contralateral invasive ductal carcinoma eight years after excision of the nipple adenoma. The third woman had concurrent contralateral DCIS biopsied one month after removal of her nipple adenoma.

With a mean follow up of 38.3 months (range = 1-155 months, median 29.0 months), there has been 1 recurrence of nipple adenoma. This recurrence occurred in a patient who had a partial excision of the nipple for resection of a 0.6 cm adenoma and 42 months later presented with bloody nipple discharge. This was treated with a re-excision of part of the nipple that revealed a 0.4 cm nipple adenoma. With 18 months follow up after re-excision, there has been no sign of additional disease.

Discussion

Nipple adenoma is a rare condition most commonly found in women with peak rates in the 5th decade.3 They have also been reported in men as well as in children as young as 5 months old.4-6

In addition to its rarity, these neoplasms are difficult to diagnose because of their non-specific presentation. Duration of symptoms prior to a clinical diagnosis ranges from 1 month to 14 years.7 In our series, all cases were diagnosed within two years of symptomatology. The most common presentation of these lesions in our series is nipple discharge. Other frequent symptoms include palpable mass, crusting, ulceration, and erythema of the nipple. Preoperative biopsy is challenging due to the lesions location within the nipple, therefore, surgical excision is both diagnostic and therapeutic.

It is important to differentiate these lesions from malignant lesions, such as Paget’s disease and invasive adenocarcinoma, since the treatments are quite different. Imaging can assist in differentiating between benign and malignant disease processes, but there are few, if any, pathognomonic radiologic findings for nipple adenoma. MRI findings have been shown to correlate with certain histologic features but do not provide diagnostic certainty in the absence of a tissue sample.8 Definitive treatment of nipple adenoma has traditionally involved complete excision of the nipple areolar complex.9 However, recent reports, including our own, have shown acceptable cure rates with partial nipple resection when the adenoma is excised with negative margins.2 Novel treatments such as cryosurgery and Mohs surgery have been reported with good outcomes as well when negative margins are achieved.10

Nipple adenomas are regarded as benign lesions. However, there have been isolated reports of malignant synchronous foci in these lesions.11 Some have questioned as to whether these adenomas serve as a precursor for malignant lesions or increase risk for future carcinoma. Epithelial hyperplasia has been suggested as a mechanism for increased risk of carcinoma development. In this series, three patients developed ductal carcinoma in situ or invasive ductal carcinoma either before or after their diagnosis of nipple adenoma. No clear correlation has ever been shown with nipple adenoma and development of breast cancer. Further investigation may be warranted to delineate a relationship between diagnoses.

Disclosures

The authors have no disclosures or conflicts of interest related to this manuscript.

References

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