Type:
Educational Exhibit
Authors:
P. L. Moyle, S. Hunter, S. O'Keeffe, R. Gaskarth; Cambridge/UK
DOI:
10.1594/ecr2010/C-0362
Imaging findings OR Procedure details
Case 1.
Background
- A 72 year old woman with previous invasive ductal carcinoma of the right breast 20 years ago, was treated by wide local excision and radiotherapy.
- She presented with a new lump in the lower inner aspect of the right breast adjacent to the previous malignancy.
- An ultrasound guided biopsy of the area failed to identify malignant cells and therefore an MRI was arranged.
Imaging
- T1-W images demonstrate an irregular low signal intensity (SI) mass (figure 1) which displayed increased SI on T2-W imaging (figure 2).
- Post intravenous gadolinium* contrast medium there was predominantly peripheral enhancement (figure 3) with a type 1 or slow rising enhancement curve ( figure 4).
- DWI ( b-value 700, 4 Nex) demonstrated restricted diffusion ( figure 5).
- ADC values were very high 1.93 x 10-3 mm2s-1 ( deviation 0.3 x 10-3) a therefore mucinous tumour was considered ( figure 6).
- A repeat biopsy of the lesion confirmed a grade 2 mucinous tumour.
Learning points
- The postulated diagnosis included post radiotherapy fat necrosis or low grade malignancy due to the irregular morphology and slow rising enhancement curve suggestive of benign pathology.
- The high ADC value was higher than expected for a benign lesion and therefore was suggestive of a mucinous tumour.
- At our institution, an ADC value greater or equal to 1.41 x 10-3 mm2s-1 ( p < 0.0001) is considered benign , which allows a high sensitivity (82 %) and specificity (72 %) to discriminate between benign and malignant lesions.
Case 2.
Background
- A 66 year old woman had a screening mammogram and a 2cm spiculate mass was identified in centrally in her right breast.
- Ultrasound guided biopsy suggested a mucinous tumour but was inconclusive.
Imaging
- The spiculate mass demonstrated low SI on T1-W imaging and increased SI on T2-W imaging.
- Post intravenous gadolinium* contrast medium, there was contrast enhancement (figure 7) with a type 1 or slow rising enhancement curve ( figure 8) suggestive benign pathology.
- DWI (b-value 700, 4 NEX) demonstrated restricted diffusion ( figure 9).
- ADC values were very high 2.08 x 10-3 mm2s-1, (0.137 x 10-3 deviation) helping to confirm the initial pathology of a mucinous tumour( figure 10).
Teaching points
- The high ADC value of the mass suggesting a mucinous tumour was concordent with the inital provisional pathology, therefore a further repeat biopsy pre surgery was not necessary.
- Histology post wide local excision confirmed the grade 3 pure mucinous tumour.
Case 3.
Background
- A 69 year had a biopsy proven mucinous tumour of the right breast.
- As part of her tumour assessment prior to chemotherapy a pre chemotherapy MRI was performed.
- An MRI compatible tumour maker coil had been inserted under ultrasound guidance into the tumour to mark its site.
Imaging
- A round 2.5cm mass in the upper outer quadrant of the left breast demonstrated low SI on T1-W imaging and increased SI on T2-W imaging.
- There is signal loss centrally at the site of the tumour marker clip, but there is no significant susceptibility artefact associated with the clip on this occasion.
- Post intravenous gadolinium contrast * there was indeterminate contrast enhancement ( figure 11) with type II or plateau enhancement ( figure 12).
- DWI (b-value 700, 4 NEX) demonstrated restricted diffusion (figure 13).
- ADC values were high 1.83 x 10-3 mm2s-1, (0.285 x 10-3 deviation) confirm the initial pathology of a pure grade 3 mucinous tumour ( figure 14).
Teaching points
- The limitations of the DWI are underestimation of ADC due to susceptibility artefact; from metal tumour marker coils, blood products (for example post biopsy), and limited spatial resolution [8].
*0.15 mmol/kg dimeglumine gadopentetate solution, 3mls/second (Magnevist; Schering Health Care Ltd, Burgess Hill, U.K).