Case Quiz (October 2016)

A 11-year-old boy was diagnosed with familial Mediterrenean fever (FMF) with homozygous for M694V mutation of the MEFV gene and was started on colchicine therapy 4 years before admission. He was uncompliant to therapy and was admitted to a local hospital with complaining of fever, malaise, abdominal pain and arthralgia lasting for 2 months. Multiple hypoechogenic mass lesions were detected on liver and kidneys with ultrasonography (US) and diagnosed to be hematomas by laparoscopic examination. He was referred to a tertiary hospital because of development of convulsions. On physical examination his blood pressure was 140/90 mmHg and body temperature was 39 °C. He was pale and extremely cachectic, with atrophic muscles of the extremities. He had diffuse abdominal tenderness and hepatosplenomegaly. Laboratory investigations revealed a hemoglobin of 9.8 g/dl, white blood cell count 9,900/mm 3 , platelets 213,000/mm 3 , ESR 112 mm/h, CRP 78 mg/L and fibrinogen 500 mg/dl. Electrolytes, renal and hepatic functions and urinalysis were normal. Examinations of peripheric blood smear and bone marrow aspiration were normal. Bleeding profile was normal. Bacterial cultures of blood, urine and stool grew no organisms. Serological tests for hepatitis B and C, cytomegalovirus, salmonella and brucella were negative. During the follow-up period, he had an attack of macroscopic hematuria with loin pain lasting for 2 days. Multiple hematomas were demonstrated on the liver and bilateral kidneys with abdominal US and computed tomography (CT). Cranial magnetic resonance imaging (MRI) showed changes of intensity at the cortical and subcortical levels of bilateral parietal, occipital and left frontal regions, suggesting hypertensive posterior leukoencephalopathy.

Case Answer (October 2016)

Polyarteritis nodosa is a systemic necrotizing vasculitis of unknown origin, with manifestations in various organ systems. Renal and gastrointestinal involvement due to multiple infarctions and aneurysms are characteristic of PAN. This patient with high-grade fever and multiple hematomas was initially suggested to have a bleeding disorder or an infectious disease. Normal bleeding test results, negative culture findings and serological tests for various bacterial or viral infectious agents excluded these possibilities. Concurrent occurrence of multiple hematomas in both kidneys and liver was hardly suggestive of malignancy. The other possibilities are vascular diseases including arteriovenous malformation, aneurysm, infarction and vas- culitis, such as polyarteritis nodosa (PAN) and granulomatosis polyangiitis (Wegener’s granulomatosis). The association of familial Mediterranean fever (FMF) and vasculitis is well known, and PAN occurs in approximately 1% of FMF patients. Visceral hematomas are known but rare complications in FMF and PAN, and peri-renal hematoma may be an initial manifestation of the disorder. Spontaneous subcapsular and peri-renal bleeding is caused by rupture of micro- aneurysms at the arcuate and intralobular arteries.

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