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Page 2 of 5 Goh et al. Mini-invasive Surg 2019;3:17 I http://dx.doi.org/10.20517/2574-1225.2019.06

computed tomography (CT) scan of the chest, abdomen and pelvis showed a heterogeneously enhancing
mural thickening of the lower esophagus, with no enlarged regional lymph nodes and a fluorodeoxyglucose
positron emission tomography (FDG PET) scan did not show any nodal or distant metastasis. He underwent
neoadjuvant chemotherapy and radiotherapy, followed by Ivor Lewis esophagectomy, total gastrectomy
and colonic interposition. Final histology showed invasive poorly differentiated adenocarcinoma at the
gastro-esophageal junction, arising in the background of Barrett’s esophagus. The tumor invaded the peri-
esophageal adventitia and involved the serosa of stomach with extensive peri-neural invasion seen. All
45 lymph nodes were negative for malignancy and the final staging was pT4aN0M0 with clear resection
margins. His case was discussed at the gastrointestinal tumor board and decision was for surveillance alone,
without a need for adjuvant chemotherapy or radiotherapy. He was followed up with surveillance CT scan of
the abdomen and pelvis and was noted to have new onset moderate left hydronephrosis 9 months after the
operation. The left hydronephrosis extended all the way down to the urinary bladder with no obvious cause
of obstruction or lesions noted. He underwent a ureteroscopy and was noted to have a 4-cm tight distal
ureteric stricture with unhealthy looking ureteric mucosa, but no obvious bladder or ureteric lesion [Figure 1A].
Balloon dilatation of the ureteric stricture was performed and a double-J stent was inserted, which was
removed 2 weeks later. He was planned for follow up CT intravenous pyelogram to evaluate the ureteric
stricture but was subsequently noted to develop acute kidney injury with a rise in serum creatinine. A non-
contrast CT scan of the abdomen and pelvis now showed an area of bladder wall thickening in the region
of the left ureteric orifice with worsening hydronephrosis [Figure 1B]. He underwent a rigid cystoscopy
and was noted to have edematous bladder wall mucosa with solid looking areas and had a transurethral
resection of bladder tumor performed; histology showed normal urothelium with submucosal infiltration by
metastatic adenocarcinoma with signet cell morphology. Immunostains show the carcinoma cells staining
positively with CK7 and CK20, and negatively with CDX2, TTF1, Napsin A, S100, GATA3, PSA and PSAP.
These findings were in keeping with metastatic poorly differentiated adenocarcinoma of esophagus/gastric
origin. A re-staging FDG PET CT scan was performed and did not show any obvious nodal or distant
metastasis. He was referred to the medical oncologist for palliative treatment of the metastatic esophageal
cancer.

DISCUSSION
Esophageal cancer is the eighth most common cancer worldwide and esophageal cancer most commonly
metastasize to the liver and peritoneum, regional lymph nodes, lung, stomach, kidney, adrenals and
[1]
bone . Esophageal cancer can metastasize via several different routes; with direct invasion, lymphatic and
hematogenous spread being the more common routes of spread. Other mechanisms of metastasis include
trans-peritoneal and intra-luminal implantation. The most common sites of esophageal metastases include
liver, regional lymph nodes and lung, but unexpected sites of metastasis have increasingly been reported.
It is unclear how esophageal cancer can spread to the urinary bladder, but one possibility may be via the
hematogenous route.

[2]
Shaheen et al. performed a systematic review on esophageal cancer metastases to unexpected sites and
found 164 cases reported, of which there were 14 cases of metastatic spread to the urinary tract (10 to kidney,
2 to penis and 2 to testis/spermatic cord), but none was found to have spread to the urinary bladder.

Metastatic spread to the bladder constitutes 2% of all bladder neoplasms, and most commonly they occur by
[3]
[4]
direct invasion rather than from distant spread . Velcheti and Govindan reviewed 264 cases of metastatic
disease to the bladder and found the most common primary site to be genitourinary and colorectal; and
melanoma, breast and stomach are the commonest primary foci for distant spread.

The urinary bladder is an extremely rare site of metastasis from the esophagus with less than 5 cases
reported worldwide. An extensive literature search found only four reported cases of metastatic disease to