AB1132 Manifestation of juvenile arthritis as a mask of acute lymphoblastic leukemia: The role of MRI in the diagnosis
Authors: D. Alekseev, I. Nikishina, A. Smirnov
Journal: Annals of the Rheumatic Diseases (2013)

<h3>Objectives</h3> To present the importance of the need to remember the differential diagnosis of tumors in patients with juvenile arthritis, even in the case of a typical clinical picture of disease. <h3>Methods</h3> Presentation of clinical picture of patient who had clinically almost typically manifestations of JA, with final diagnosis – acute lymphoblastic leukemia (ALL). <h3>Results</h3> The patient, male, became ill at the age of 16.5 years. Before admission to our Institutehe was observed in a small rheumatology department at the place of residence. During this time, the clinical picture was presented subfebrile fever, complainingof pain in temporomandibulars, elbows, knees and small joints of hands and feet; skinpapular rash, considered as a manifestation of streptococcal infection. Laboratory examinations: leukopenia (3.5-2.0Í10<sup>9</sup>), ESR and CRP normal; blood culture "negative". The absence of visceral lesions. MRI of wrists: marked enhancement MR signal (T2WI) from the zone of the epiphyses and metadiaphysis of all bones. The foregoing was the basis for a diagnosis: streptococcal arthritis. He received treatment with high doses of glucocorticoids (GC) (prednisone p/e 60 mg a 2; methylprednisolone pulse therapy a 3, 1 g). The patientwas hospitalized in our clinicwithillness duration of 6 months.First examinationrevealed a symmetrical polyarthritis (elbows, wrists, MCP and PIP joints of the hands, knees, ankles, MTP and IP joints ofthe feet) with the presence of contractions of elbow joints, dactylitis 2 and 3 toes, severepain on palpation of the epiphysis and diaphysis of proximal phalanges of hands, the patella, the lateral surface of the right calcaneus.There were a lot of papular rash on the face and body.Laboratory examination: Hb 139, WBC 5.9, PLT 425, ESR 4 mm/h, CRP "normal", normalbiochemical indices,lack ofimmunological disorders (ANA, RF, ACCP, RNP). HLA B27 negative. The absence ofvisceral lesions according to the comprehensive examination, except for a small increase in the spleen up to 130×64 mm.Important in the diagnosis was to evaluate the results of MRI of hands, made earlier. Based onthese data, we suspected non-rheumatological disease, accompanied bychanges in bone marrow. In this regard, we performedMRI of knee and ankle joints, which showed the presence of foci, with increased MR signal on T2WIand decreased on T1WI. Patient were examined in a specializedoncology department; bone marrow examinationrevealed the presence of35.4% blast cells,morphologicallylymphoblasts. Set ofdata allowedto diagnose - ALL.He was directed for treatment in a specialized oncology department. Thus, a careful examination ofa number ofstudies, mostimportant of whichwas theMRI, allowed usto assumethat the changes of musculoskeletal system —manifestationof non-rheumatologicaldisease. The mostlikely explanation for thepeculiarities ofthe manifestationsof ALL, namely the absence ofchanges in the peripheralblood, is amodificationof the disease by highGCtherapy. <h3>Conclusions</h3> The presenteddata confirm the difficulty of diagnosis of JA.Rcareful study ofdata from medical history, clinical and paraclinical investigations helps to recognize the diagnosis. Used therapy can alter the manifestations of the disease. <h3>Disclosure of Interest</h3> None Declared