PMC6280009_01
PET-CT scan of chest, abdomen, and pelvis. Coronal reformatted image obtained 90 min after IV administration of 14.0 mCi of F18-FDG demonstrating a solitary focus of intense activity noted within the cecum with a maximum standardized uptake value of 9.6 (denoted by the blue arrow). At the time, this was suspicious for a colonic primary tumor.
gr1.jpg
PMC6280009_01_gr1.jpg
fig0005
It also showed an abnormal hypermetabolic focus in the cecum suspicious for a colon primary (Fig. 1, Fig. 2).
Abdominal CT image at admission with IV and oral contrast. Multiple contiguous axial images of the abdomen and pelvis were obtained following the administration of intravenous and oral contrast. The appendix is dilated to 1.8 cm with significant periappendiceal stranding and appendiceal wall thickening (blue arrow). Also in the right lower quadrant, either adjacent to or within the wall of the cecum, is a bowel mass measuring 2.3 x 1.9 x 2.3 cm, concerning for a malignancy (demonstrated by the red arrow).
gr3.jpg
PMC6280009_01_gr3.jpg
fig0015
IV and oral contrast, the appendix was dilated to 1.8 cm with appendiceal wall thickening and periappendiceal stranding. In addition, a 2.3 x 1.9 x 2.3 cm bowel mass was identified in the right lower quadrant either adjacent to or within the wall of the cecum that correlated with the previous PET-CT scan performed in May 2017 (Fig. 3).
Hematoxylin and eosin (H&E) stain at 40x magnification demonstrating the tumor from the colectomy specimen (green arrow) within the submucosa with an overlying, benign colonic mucosa (red arrow).
gr4.jpg
PMC6280009_01_gr4.jpg
fig0020
The right colon specimen returned as metastatic breast carcinoma involving cecal submucosa clear of margins with overlying benign colonic mucosa (Fig. 4).
Histological examination. The following findings demonstrate invasive ductal breast carcinoma. A. Nests of tumor cells with basophilic mucin production (H&E of colon tumor, 100x magnification). B. Tumor composed of cords and nests of epithelial cells with eosinophilic cytoplasm and prominent nucleoli (H&E stain of colon tumor, 400x magnification). C. Positive nuclear staining for Gata3 (Gata3 immunohistochemical stain, 200x magnification). D. Negative for CDX2 (CDX2 immunohistochemical stain, 200x magnification).
gr5.jpg
PMC6280009_01_gr5.jpg
fig0025
The specimen stained strongly and diffusely for GATA3 which was consistent with metastatic breast carcinoma and negative for CDX2 (Fig. 5A-D).