A 53-year-old woman presented with a history of abdominal pain, nausea, vomiting,
and a 40-kg weight loss, without change in bowel pattern. Physical examination revealed
epigastric tenderness, good bowel sounds, and an abdominal fluid wave. Rectal examination
was normal without occult blood. Abdominal computed tomography (CT) scan revealed
a hypodense area of enlargement in the head of the pancreas, ascites, and multiple
metastatic lesions in the liver, and normal bowels.
Endoscopic ultrasound (EUS) was performed to evaluate the pancreas. In the head of
the gland there was a lobular and irregular hypoechogenic structure measuring 25 ×
28 mm (Figure [1]). The lesion also had what appeared to be pseudopods extending into the pancreatic
head. EUS-guided fine-needle aspiration was performed. Cytologic evaluation demonstrated
adenocarcinoma. The tissue stained positive for CK20 and negative for CK7 and showed
uniform immunoreactivity with CDX2. These results strongly suggested a primary colorectal
cancer and not a primary pancreatic adenocarcinoma.
Figure 1 Mass in the head of the pancreas, seen at endoscopic ultrasound (7.5-MHz curvilinear).
The lesion is hypodense and of mixed echotexture, and appears to have pseudopods extending
into the pancreatic head.
Colonoscopy revealed a large, partially obstructing mass in the ascending colon, just
above the ileocecal fold (Figure [2]). The patient was offered a palliative partial colectomy or placement of a colonic
stent. The patient did not wish to pursue surgery, and a 22 × 90-mm colonic self-expanding
metal stent (Boston Scientific, Natick, Massachusetts, USA) was placed across the
stricture, with the proximal end of the stent in the cecum. Her bowel remained patent
until her death 2 months later.
Figure 2 Endoscopic appearance of colonic malignancy seen in the right colon, immediately distal
to the ileocecal fold.
Reports of colon cancer metastasizing to the pancreas are very uncommon [1]. Immunohistochemically, the CK7-/CK20+ phenotype seen here predicts colorectal origin
with considerable accuracy and independently of other clinical information [2]. CDX2 stains homogeneously in tissue arising from the colon (as was seen here) or
duodenum and heterogeneously in pancreatic adenocarcinoma [3]. This is only the third report of EUS detection of colorectal cancer metastasis
to the pancreas [4.5].
Endoscopy_UCTN_Code_CCL_1AF_2AZ_3AB
