Large breast lump with bloody nipple discharge: benign intraductal papilloma

Abstract

A 32-year-old woman presented with a 3 cm×3 cm left breast lump associated with bloody nipple discharge during her early pregnancy. Examination and ultrasonography showed benign features, whereas core needle biopsies revealed a benign papilloma. Six months after her delivery, a 6 cm×6 cm benign papilloma was completely excised via circumareolar incision. The majority of intraductal papillomas are small; however, they can also present as a large mass rarely. We should be wary of a malignant papillary lesion when there is the presence of atypia on core needle biopsy or imaging-histology discordance. A concordant benign papilloma with benign imaging findings is otherwise reassuring. Clinicians need to be aware of this uncommon presentation of large intraductal papilloma as a complete curative excision can be achieved through a cosmetically placed incision.

Background

Breast lumps and nipple discharge are common presenting complaints among women of childbearing age. The majority of these lesions are benign, although a small proportion can harbour malignant cells. We need to be aware of intraductal papilloma as an uncommon differential diagnosis of a breast lump.

As part of triple assessment, sometimes the histology is reported as a papillary lesion. Multiple different names are given to these papillary lesions, which can be confusing to the clinicians. We need to understand and adopt a safe and successful management approach when faced with these papillary lesions.

Case presentation

A 32-year-old housewife who was in her second pregnancy at 20 weeks’ gestation had a left breast lump. The lump has been present since 6 years ago; however, it has been increasing in size along with bloody nipple discharge for the past 5 months. The intermittent bloody nipple discharge was from a single duct and occurred spontaneously. She had no other illnesses or any family history of malignancies.

On examination, there was a 3 cm×3 cm firm, mobile lump at the lower inner quadrant of her left breast. Dark red bloody discharge from a single duct was demonstrated on nipple expression. No axillary lymph nodes were palpable.

Investigations

Breast ultrasound showed a solid well-defined lesion with dilated duct, reported as Breast Imaging Report and Data System category 3 by the radiologist.

Subsequently, core needle biopsies were taken, with a total of five cores. The tissues show complex arborising pattern with fibrovascular cores covered by a layer of myoepithelial cells and overlying epithelial cells. The epithelial cells show bland nuclear features and rare mitotic figures. No nuclear atypia or malignancy was seen. It was interpreted by the pathologist as papillary neoplasm in favour of breast papilloma.

Differential diagnosis

When she presented with unilateral single-duct bloody nipple discharge, it was considered pathological nipple discharge. Thus, the differential diagnoses include malignant lesions (invasive ductal carcinoma or ductal carcinoma in situ) or benign lesions (papilloma, ductal ectasia or benign fibrocystic changes).

As the pathological nipple discharge has a clinically palpable lump, the lesion could be a more common benign papilloma or a malignant lesion. However, we have never encountered a large palpable papilloma in our clinical practice. Therefore, working diagnoses include a rare large benign papilloma, benign fibrocystic lesions with surrounding inflammation causing the pathological nipple discharge or a malignant breast in situ or invasive lesion.

To establish a definitive diagnosis, we completed the breast triple assessment. Ultrasonography showed a benign lesion, whereas core needle biopsies confirmed a benign papilloma.

Treatment

She was seen back at the surgical clinic 6 months after delivery of her second child. The spontaneous bloody nipple discharge that occurred previously had already stopped and she only experienced serous discharge on nipple expression. However, the lump had increased in size to 6 cm×6 cm, being well defined, firm and mobile (figure 1).

Figure 1.

Lobulated mass at the lower inner quadrant of the left breast.

Following her second visit to our surgical clinic, she agreed for surgical therapy to remove the lump. A wide local excision was performed under general anaesthesia. A well-defined lobulated mass measuring 6 cm×6 cm was excised through a circumareolar incision (figures 2 and 3). Breast cavity was approximated using the breast tissue mobilisation technique. Postoperative recovery was uneventful.

Figure 2.

Papilloma excision through circumareolar incision.

Figure 3.

Excised papilloma measuring 6 cm×6 cm.

Outcome and follow-up

The excised specimen histology showed a partly circumscribed lesion displaying a cohesive and arborising structure composed of fibrovascular cores lined by a layer of myoepithelial cells with overlying luminal epithelial cells. Epithelial cells have mildly pleomorphic vesicular nuclei with conspicuous nucleoli. Mitosis was rarely encountered (one per high-power field). Apocrine metaplasia occasionally observed. Excision margin was complete and there was no evidence of malignancy.

She was last seen at the surgical clinic 4 months postoperatively. Her circumareolar scar had healed well, her nipple discharge had disappeared and there was no loss of nipple sensation. She was satisfied with the cosmetic surgical outcome.

Discussion

In patients presenting with pathological nipple discharge, solitary ductal papilloma is the cause 40% of the time, whereas malignant lesions constitute only 13.4%.¹ Usually intraductal papillomas are small and detected via imaging done during investigation for a pathological nipple discharge.

However, large intraductal papillomas have been reported in the literature (table 1). Their ages ranged from very young, 11 years old,² to very old, 80 years old.³ Three of the reported cases had bloody nipple discharge,^3–5 one had serosanguinous discharge⁶ and the other four did not experience nipple discharge. Their sizes ranged from 4 cm² to 20 cm×15 cm.³ Our patient had a bloody nipple discharge, and the size was 6 cm×6 cm.

Table 1.

Summary of key findings of reported cases of large intraductal papilloma and comparison with our case

First author	Year	Age (years)	Nipple discharge	Size (cm)	Duration of disease	Imaging modality	Treatment
Bloem and Misere2	1971	11	None	4	5 weeks	N.A.	Excision biopsy
Kihara12	2010	46	None	15×4x13.3	1 year	Mammography Ultrasound MRI	Repeated aspiration +resection
Roy et al10	1985	59	None	15×13x11	2 years	N.A.	Simple mastectomy
Singh et al6	2010	45	Serosanguinous	10×8x4	6 months	N.A	Simple mastectomy
Kavolius et al5	2001	39	Bloody	11	2 years	Mammography Ultrasound MRI	Excision
Wang and Lou4	2018	19	Bloody	12×8	8 years	MRI	Lumpectomy
Fatemi et al3	2015	80	Bloody	20×15	2 years	Mammography Ultrasound MRI	Total mastectomy
Altunkeser13	2017	45	None	6.5×6	N.A.	Mammography Ultrasound	Excision biopsy
Cheah	2020	32	Bloody	6×6	6 years	Ultrasound	Excision

N.A., not available.

When a biopsy for a breast lump was reported as a papillary lesion by the pathologist, clinicians need to differentiate between a benign, suspicious or malignant lesion. Lesions labelled as papilloma, papillary hyperplasia without atypia or papillomatosis are benign.⁷ In asymptomatic small lesions, those with benign biopsies can be followed up with serial imaging.⁸

To avoid missing a malignant lesion, we should be satisfied that adequate and targeted biopsy sample sites were obtained, preferably image-guided. A minimum of three cores are required to achieve a good accuracy of 98.8%.⁹ We should also ensure there is concordant benign imaging and histological findings. In our patient who presented in her early pregnancy, excision was performed 6 months after delivery of her second child. A delayed surgery was acceptable as the core needle biopsy showed benign papilloma. The risk of missing a malignant foci in her was 7%⁸; however, we sent five cores of needle biopsies from different sites which were very accurate, approaching almost 100%.⁹

A typical papilloma has a solid mass showing papillary branching pattern of fibrovascular cores in a cystic cavity. The fibrovascular core consists of central vessel, myoepithelial cells at the base and epithelial cells facing cystic cavity.⁷ The patient’s histology showed these typical fibrovascular cores.

In the 1-year waiting period, her lump had doubled in size. This might pose a problem in future if delayed further, regarding surgical options, where some of the reported patients with giant intraductal papilloma needed mastectomy due to large lesion size.^{3 6 10} However, among all the reported cases of large intraductal papilloma, none had recurred irrespective of either simple excision or mastectomy, as long as the lesion was completely excised. We achieved this surgical aim of complete excision through a circumareloar incision that healed with good cosmesis.

In other situations where there are discordant imaging and histology or the presence of atypia in the biopsy specimen, researches have found a higher risk of underestimating a malignant papillary lesion.⁸ These atypical lesions need to be excised and cannot be managed with imaging follow-up as they could be malignant. Important histology findings pointing towards a malignant lesion are the absence of myoepithelial cells, the absence of apocrine metaplasia, absent or scanty connective tissue stroma, hyperchromatic nuclei and cribriform glandular pattern.¹¹ These malignant papillary lesions can then turn to be micropapillary ductal carcinoma in situ, encysted papillary carcinoma or invasive micropapillary ductal carcinoma.⁷

Among the reported cases of large intraductal papilloma, the big size did not influence their final histology outcome of a benign papilloma. Therefore, a complete surgical excision is sufficient with aims for both curative and cosmetic outcomes.

Learning points.

• Bloody nipple discharge always requires investigation.

• Intraductal papilloma can occasionally present as a large breast lump.

• Triple assessment is essential.

• Discordant imaging-histology or the presence of atypia is an indication for excision in addition to the presence of symptomatic lesions.

• Complete excision of the large papilloma is curative.