Reiko Woodhams MD, Presenter: Nothing to Disclose

Satoko Kakita MD, Abstract Co-Author: Nothing to Disclose

Hirofumi Hata, Abstract Co-Author: Nothing to Disclose

Keiichi Iwabuchi, Abstract Co-Author: Nothing to Disclose

Masaru Kuranami, Abstract Co-Author: Nothing to Disclose

Shinichi Kan MD, Abstract Co-Author: Nothing to Disclose

Hiroshi Nishimaki MD, Abstract Co-Author: Nothing to Disclose

Robyn Leah Birdwell MD, Abstract Co-Author: Nothing to Disclose

Hiroto Hatabu MD, PhD, Abstract Co-Author: Grant, Toshiba Corporation

Carolyn Mountford DPhil, Abstract Co-Author: Nothing to Disclose

Kazushige Hayakawa MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

The goal is to determine if diffusion weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps of mucinous carcinoma (MC) of the breast exhibit unique appearance allowing them to be distinguished from other breast malignancies.

Two hundred and seventy seven patients with breast tumors were examined by DWI and apparent ADC maps, DWI was performed at 1.5T (b-value of 0 and 1500s/mm2). ADC maps were rendered from DWI on a workstation and the ADC values were measured by using a ROI over the whole tumor. By correlative histopathology, fourteen of the 277 were found to have MC of which 11 were pure type and 3 mixed type. The remaining cases were; benign 60; carcinoma (Ca) (including DCIS) 202. The p value was significant at < 0.05 (Mann-Whitney U test).

The recorded ADC values were as follows: benign 1.35± 0.31×10-3mm2/s; Ca/DCIS 0.93±0.20 ×10-3mm2/s; and MC (1.93±0.40×10-3mm2/s) which was statistically higher than that of other malignancies(P<0.001) by a factor of 2. The 3 mixed mucinous cases had an ADC of 1.43±0.30 ×10-3mm2/s whereas the 11 pure mucinous cases had an ADC 2.02±0.38 ×10-3mm2/s. Three cases of the 14 MC showed homogeneously high ADC values and all were pure category, which showed rich with mucin- floating small cancer foci on the pathologic specimens. Eleven cases out of 14 MC, which showed inhomogeneous ADC values, had single or multiple compartments separated with band-like or nodular structures were of low ADC value, included 8 pure types MC and 3 mixed types MC. In these cases, the low ADC value band-like or nodular structures corresponded to either the fibrovascular bundle or increased cell density areas including invasive ductal component when present.  

ADC values of MC were 2 fold higher than other categories of breast cancer. The method clearly distinguished Ca/DCIs from both mixed type and pure type MC. However the ADC value for mixed type MC was not statistically different from the benign category. The high ADC values of MC appear to reflect the internal histological structure i.e. mucin with low cellurality. The low ADC values may reflect fibrovascular bundles, increased cell density, and/or invasive ductal component.

When a breast tumor includes an area with high ADC value, this suggests the possibility of a pure mucinous carcinoma.

Woodhams, R, Kakita, S, Hata, H, Iwabuchi, K, Kuranami, M, Kan, S, Nishimaki, H, Birdwell, R, Hatabu, H, Mountford, C, Hayakawa, K, et al, , Mucinous Carcinoma of the Breast: Diffusion-weighted Imaging with Apparent Diffusion Coefficient Maps and Histologic Correlation.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6006914.html