Breast solitary intraductal papilloma

Clinical History

Forty-four years old female with unilateral bloody nipple discharge (left breast). Patient also referred a palpable sub areolar nodule. On physical exam, the left nipple showed significant inflammatory signs and bloody discharge was confirmed. Left nipple was very painful. No changes were found in the right breast.

Imaging Findings

Breast ultrasound showed a hypoechogenic ill-defined nodule with 10 mm in subareolar region (Fig. 1). Breast MR was performed. Bilateral thin-walled cysts were found; most of them with a high SI on T2-wi and low SI in T1-wi (Fig. 2). No enhancement was noted (Fig. 3). These features were consistent with fibrocystic breast changes.
The left nipple was more prominent than the contra-lateral nipple and a nodule with 16 mm, isointense in both T1 and T2-wi, was found in this location (Fig. 2). An early and intense uptake with later wash-out effect was noted (Fig. 2). Left subareolar dilated ducts were also noted (Fig. 2 and 3). No other nodular breast images or axillary lymphadenopathies were found.
Few days later, exteriorization of the nodular mass in the nipple was noted by the patient and sent to pathological analysis (Fig. 4), which revealed an intraductal papilloma. In the posterior surgical procedure total lesion excision was achieved.

Discussion

Intraductal papilloma is defined as a benign proliferation of epithelial and myoepithelial cells, overlying fibrovascular stalks, creating an arborescent structure within the lumen of a duct [1]. They can arise from large central ducts, usually located in the subareolar region or in the peripheral terminal ductal lobular unit [1, 2].
Central papillomas are often solitary and associated with bloody nipple discharge, whereas the peripheral papillomas are usually multiple and clinically occult.

Solitary papillomas may appear in the mammography study as round or irregular masses in the subareolar region associated with dilated ducts; rarely, microcalcifications can be seen [1, 2]. Duct dilatation with an intraluminal well-defined hypoechoic solid mass is a typical sonographic characteristic of intraductal papilloma. However, if there is no significant duct dilatation, this imaging feature may be more difficult to identify. Typically, ducts are dilated between the tumour and the nipple. Ductography is a useful modality in patients with nipple discharge; a repletion defect is the characteristic finding. MRI role for evaluation of intraductal papillomas is unclear; it can be useful to evaluate the extension of the disease in multiple papillomas or to evaluate extension of DCIS in atypical papillomas with DCIS [2]. Most appear as round, ovoid or lobulated masses isointense in T1 and T2-wi sequences with or without duct dilatation [3]. Variable enhancement patterns have been described, but a homogenous pattern was the most specific characteristic [3].
MR ductography using a microscopic coil has been described as a better technique than conventional MR for detection of small papillomas [4].
Nevertheless, isolated imaging findings often cannot differentiate papillomas from invasive carcinoma [1-4] and pathological confirmation is necessary.
Apart from that, some theories support that peripheral papillomas have an increased risk of carcinoma, whereas solitary central papillomas do not.
Surgical excision is unanimously recommended for papillomas with atypia or malignancy diagnosed by core biopsy. As for other cases of papilloma, follow-up is still controversial, and some authors also recommend excision.

Differential Diagnosis List

Final Diagnosis

Solitary intraductal papilloma

URL:	https://www.eurorad.org/case/12427
DOI:	10.1594/EURORAD/CASE.12427
ISSN:	1563-4086