A 49-year-old man of Japanese and British ancestry was referred to a metabolic diseases clinic for evaluation 5 months after nontraumatic spleen rupture requiring splenectomy. Prior history included hypertension and mild frontal headaches, but no other neurological or cardiovascular symptoms. The patient did not smoke and used alcohol infrequently. His mother had coronary artery disease, and his father had mild hypertension. There was no family history of consanguinity, splenomegaly, diabetes, or developmental delay.
Student Discussion Document (pdf)
Amit R. Rahalkar,1 Jian Wang,1 Sandra Sirrs,2 James Dimmick,3 Daniel Holmes,4 Nadine
Urquhart,4 Robert A. Hegele,1* and Andre Mattman2
1Robarts Research Institute and Schulich School of Medicine and Dentistry, University of Western
Ontario, London, Ontario, Canada; 2Adult Metabolic Disease Clinic, Department of Medicine,
Vancouver General Hospital, UBC, Vancouver, British Columbia, Canada; 3Department of Pathology
and Laboratory Medicine, Children’s and Women’s Health Centre of British Columbia, UBC,
Vancouver, British Columbia, Canada; 4Department of Pathology and Laboratory Medicine, St.
Paul’s Hospital, UBC, Vancouver, British Columbia, Canada.
*Address correspondence to this author at: Robarts Research Institute, 406-100 Perth
Drive, London, Ontario, 519 663 3037; e-mail firstname.lastname@example.org.
A 49-year-old man of Japanese and British ancestry was referred to a metabolic diseases
clinic for evaluation 5 months after nontraumatic spleen rupture requiring splenectomy.
Prior history included hypertension and mild frontal headaches, but no other
neurological or cardiovascular symptoms. The patient did not smoke and used alcohol
infrequently. His mother had coronary artery disease, and his father had mild
hypertension. There was no family history of consanguinity, splenomegaly, diabetes, or
The ruptured spleen weighed 727 g, and splenomegaly was associated with marked
sinus histiocytosis spreading apart the lymphoid component. The overwhelming majority
of histiocytes were foamy, and only a few had sea-blue appearance and reacted positively
with periodic acid-Schiff (PAS), PAS and diastase, and May-Giemsa stains. A lipid
storage disorder was suspected, but the histiocytes did not have the cytoplasmic linearity
appearance of Gaucher cells and were otherwise nonspecific. Before splenic rupture, the
patient’s lipoprotein profile was reported as being normal, with no past recorded
triglyceride measurement exceeding 2 mmol/L.
Two-month postsplenectomy laboratory investigations revealed combined
hyperlipidemia with plasma total cholesterol, HDL-cholesterol, and triglycerides of 7.9
(normal <5.2), 1.4 (normal >1.0), and 4.3 (normal <1.7) mmol/L, respectively. Liver
function tests were normal aside from increased γ glutamyltransferase (88 μg/L; normal
<49 μg/L). Hemoglobin and leukocyte counts were normal with mild thrombocytosis.
Physical examination at 5 months revealed obesity (body mass index 28.9 kg/m2) and
hypertension (resting blood pressure 140/100 mm Hg). Cardiovascular examination was
normal. There were no xanthomata or xanthelasmata and no hepatomegaly. Left
ventricular ejection fraction by echocardiogram was normal at 50%. Coronary artery
computed tomographic scan revealed no obvious arterial occlusion, and brain MRI
revealed nonspecific white matter changes consistent with ischemia. Carotid artery
ultrasound showed no significant obstruction.
Six months postsplenectomy, the patient’s plasma triglycerides were 17.2 mmol/L. He
was placed on a seafood-rich, low-fat, low-sugar diet. At 8 months his plasma
triglycerides had fallen to 1.5 mmol/L, while total cholesterol and HDL-cholesterol were
8.2 and 1.2 mmol/L, respectively, and apolipoprotein (apo)B and apoA-I concentrations
were 1.19 and 1.35 g/L, respectively. The patient’s dietary regimen was relaxed, and at 12
months triglycerides had again increased to 21.1 mmol/L. In view of findings suggesting
cardiovascular disease and recurrent severe hypertriglyceridemia, aspirin and
antihypertensive, and lipid-lowering therapies (atorvastatin 10 mg/day and salmon oil 3
g/day) were initiated. Genomic investigation was requested.
Questions to Consider
- What is the etiology of non-traumatic splenomegaly?
- What is the etiology of primary hypertriglyceridemia?
- How are common apo E isoforms related to an individual’s lipid profile?
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