Case Study: Fever and low platelets
A 66-year-old woman with a history of sarcoidosis and hypertension presents to the emergency department for 4 days with right-sided abdominal pain, vomiting, fever, and mild diarrhea without blood. She denies having any blood in her emesis or any other complaints. When asked about prior abdominal surgery, she confirms that she still has her gallbladder and appendix. When asked about foreign travel or recent antibiotic use, she denies both but mentions that she was recently hiking in the Sierra Mountains in California.
On physical examination, her vital signs are all normal except for a temperature of 102.1° F and a pulse of 106 bpm. Her exam is otherwise normal except for generalized abdominal tenderness with guarding isolated to the right upper quadrant only and a few petechiae on both shins.
The patient's blood work is notable for a sodium level of 127 mEq/L, an aspartate transaminase (AST) of 441 U/L, an alanine transaminase (ALT) of 288 U/L, and a platelet count of 14,000. An abdominal ultrasound is ordered and shows an enlarged liver with a dilated gallbladder but no stones, wall thickening, or pericholecystic fluid. The spleen is also noted to be enlarged. A blood smear is done due to the low platelets and is shown below.
What diagnostic findings are shown in the smear below? What is the most likely diagnosis?
HINT: The patient's recent hiking in the Sierra Mountains is relevant
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