A case of all-trans retinoic acid-induced myositis = A case of all-trans retinoic acid-induced myositis

다국어 초록 (Multilingual Abstract)

ATRA (all-trans retinoic acid) has became the standard induction therapy for acute promylelocytic leukemia (APL). With the use of ATRA for acute promylelocytic leukemia (APL), the number of reported adverse reactions is increasing, including the most frequent and fatal being the retinoic acid syndrome (RAS). ATRA-induced myositis is rarely described in patients with APL and in response to the steroids is known to be good. We report a case of a middle age man with APL (microgranular variant type) who developed ATRA-induced myositis with hemorrahagic abscess characterized by unexplained fevers, leg swelling of bilateral calf areas, and a painful purpuric petechial rash during induction treatment. Magnetic resonance (MR) imaging showed low signal intensity suggesting the diagnosis of multifocal inflammatory or hemorrhagic nodular lesion in the right soleus, left gastrocnemius, and both tibial anterior muscles, multiple areas of increased signal intensity in the anterior musculature on both leg due to myositis. And the muscle biopsy revealed acute and chronic myositis. ATRA was discontinued on day 18 and prednisone 75 mg daily was commenced. In the successive days, swelling, heating sense and painful muscle involvement disappeared. But a repeat bone marrow biopsy on day 25 showed persistence of APL with PML-RARA rearrangement. The patient of refractory state died by aggravation of pneumonia. As far as we know, this is the first case of ATRA-induced myositis in a middle age man with acute promylelocytic leukemia (APL) of microgranular variant type in korea.