Can radiology differentiate between benign and malignant papillary lesions?

Author / Copyright: Dr. Dina Elmetwally (Mansoura University)

Clinical History

27 years old female patient presented by left breast enlargement, pain & nipple discharge

Case Imaging Scenario

• This female patient was referred for breast ultrasound to detect any underlying breast abnormality.
• Breast US showed multiple dilated ducts with intraductal masses. On basis of ultrasound findings, the patient was categorized as BI-RADS 4. Biopsy was asked and further evaluation by MRI was recommended.
• When MRI was performed it showed multiple dilated ducts with multiple intraductal masses, the intraductal masses were rounded in shape with regular smooth borders, they appeared of intermediate signal intensity on STIR images and showed homogenous enhancement on early subtraction MR images. When performing time signal intensity curve, the lesions showed wash out curve. On DWI, the lesions appeared of restricted diffusion with mean ADC value of 1 x 10-3 mm2/sec.
• The washout time signal intensity curve and the restricted diffusion pattern of the intraductal masses made us could not exclude underlying DCIS and the lesions were categorized as BI-RADS 4 on basis of MRI findings and biopsy was still recommended.

Case Description /Discussion

• Multiple intraductal papillomas are less common than solitary intraductal papillomas (1). Unlike solitary papillomas, multiple intraductal papillomas are usually associated with atypia, DCIS, or malignancy (2).On mammography; small papillomas can be occult. Larger lesions may appear as a round- or oval-shaped mass with well-circumscribed margins. Up to 25% of papillomas are associated with benign-appearing mammographic calcifications (3). On ultrasound; intraductal papilloma appears as well-defined solid nodules or mural-based nodules within a dilated duct. On color Doppler, flow may be detected arising from a vascular feeding pedicle (1).On MRI: The tumor size ranged from 0.3 to 2.0 cm. The shape is usually rounded or oval, however irregular shape have been reported in many cases. Tumor margin may be smooth, irregular or microlobulated. Enhancement may be homogenous or heterogeneous. They usually show type 2 TIC (plateau curve), however type 3 TIC (washout curve) have been reported in many cases. On DWI, it appear restricted with mean ADC value=1.17 ± 0.24 × 10–3 mm2/s (4).

In our case, the washout time signal intensity curve and the restricted diffusion pattern made us could not differentiate between benign papillomas and those with ADH or DCIS. It was reported that  differentiating benign papillomas from those associated with ADH or DCIS is difficult on basis of imaging findings (1), However some MRI features like a mass size more than 10 mm, mixed mass and non-mass enhancement (NME), and NMEs with segmental or regional distribution indicate a papilloma with high-risk or malignant lesions (5).

Teaching Points;

It is difficult to differentiate benign intraductal papilloma from those associated with ADH and DCIS on basis of imaging and biopsy is mandatory for diagnosis.

Final Diagnosis;

Multiple intraductal papillomatosis with no atypia or malignancy.

Keywords;

Solitary intraductal papilloma, intraductal papillomatosis, mammography, breast ultrasound, MRI, ADH, DCIS.

References;

• Eiada R, Chong J, Kulkarni S,  Goldberg F,  Muradali D. Papillary Lesions of the Breast: MRI, Ultrasound, and Mammographic Appearances. AJR. 2012; 198:264–271.
• Mulligan AM, O’Malley FP. Papillary lesions of the breast: a review. Adv Anat Pathol 2007; 14:108–119.
• Brookes MJ, Bourke AG. Radiological appearances of papillary breast lesions. Clin Radiol. 2008; 63:1265–1273.
• Zhu Y, Zhang S, Liu P, Lu H, Xu Y, Yang WT. Solitary intraductal papillomas of the breast: MRI features and differentiation from small invasive ductal carcinomas. AJR Am J Roentgenol. 2012;199:936–42.
• Wang L J, Wu P,  Li X X,  Luo R,  Wang D B,  Guan W B. Magnetic resonance imaging features for differentiating breast papilloma with high-risk or malignant lesions from benign papilloma: a retrospective study on 158 patients. World J Surg Onc. 2018; 16 (234).

Origin of Figures;

The imaging investigations were performed at Mansoura university hospitals using the following methods.

Ultrasound machine: Toshiba Aplio 500.

MRI equipment: 1.5 T superconductive magnet device (Philips Ingenia).