Objectives The earliest manifestations of malignant diseases such as leukemia and lymphoma are diverse. The aim of this study is to determine the characteristics and frequency of rheumatic features as initial symptoms among children diagnosed as acute leukemia and lymphoma.

Methods The study is a prospective analysis of 93 children diagnosed as leukemia and lymphoma between 2013-2015. They were diagnosed and treated at pediatric hematology and oncology clinic of Kanuni Sultan Suleyman Research and Training Hospital. Each patient was reviewed for rheumatological symptoms and signs. The evaluation sheet consisted of twelve clinical features and eight signs.

Results There were 58 males (62,3%) and 35 females (37,7%) with a total of 93 patients. Acute lymphocytic leukemi (ALL) was diagnosed in 76 (81,8%) patients, acute myeloid leukemia (AML) in 13 (13,9%) patients, and lymphoma (hodgkin and nonhodgkin lymphoma) in 4 (4,3%) patients. Mean age was 78 months (range: 10-204 months). The most common symptoms were fatigue and pallor (51%), fever (25%), bone and leg tenderness (17%). Other symptoms were abdominal pain (9,6%), back pain (7,5%), weight loss (6,4%), arthritis (5,3%), arthralgia without arthritis (5,3%), and chest pain (4,3%). Five patients presenting only with arthritis had the diagnosis of acute lymphocytic leukemia. Four of them were monoarticular and one of them was oligoarticular arthritis. The large joints chiefly knees (2 patients), ankles (2 patients) and elbow (1 patient) were affected. Two patients had been diagnosed as familial mediterranean fever and were under colchicine treatment while they were diagnosed as malignancy. The physical findings included hepatosplenomegaly (36,5%), lymphadenopathy (20%), and petechia, ecchymoses or spontaneous bruising (13,9%). Abnormal laboratory findings in the leukemia group included anemia (65%), thrombocytopenia (76%), leukopenia (25%), leukocytosis (26%), and elevated LDH and ESR levels. The laboratory findings were normal with the exception of one patient in the lymphoma group who only had leukopenia.

Conclusions Rheumatological signs and symptoms are not uncommon findings that were faced at hematology-oncology outpatient clinics. Children diagnosed with malignant diseases may present with rheumatological symptoms as initial manifestations. In the differential diagnosis of juvenile rheumatological diseases, malignancies should be kept in mind. Pediatricians facing with atypical symptoms should be aware of these features in malignant diseases.

Disclosure of Interest None declared