To the Editor:
A 44-year-old healthy, active man presented to an
outside hospital complaining of a 1-day history of fever up
to 39�C, muscle aches, sinus pressure, nausea, vomiting,
and diarrhea in April 2015. Review of systems was negative
for abdominal pain, hematochezia, or melena. A chest
radiograph was negative for infiltration, consolidation,
edema, or other pathology. Lipase level was 37 U/L (within
normal limits). A nasopharyngeal swab antigen test was
positive for influenza B, and the patient was discharged on
oseltamivir. Three days later, intermittent fevers persisted
with chills, nausea, vomiting, and severe abdominal pain.
Anorexia developed, and the patient described “something
twisting and pulling at [his] insides.” An abdominal
computed tomography scan showed extensive superior
mesenteric vein thrombosis, which extended into the main
portal vein and proximal splenic vein. He was transferred to
our facility for transhepatic thrombolysis, which was complicated
by intrahepatic hematoma requiring subselective
hepatic artery embolization. He recovered completely and
was discharged with rivaroxaban. Hematology evaluation
was negative for predisposing hypercoagulable conditions
including factor II mutation, factor V Leiden, and lupus
anticoagulant. Of note, his past medical, surgical, and family
history were unrevealing for malignancy, coagulopathy,
cirrhosis, pancreatitis, or other prothrombotic states
