CASE REPORT Mehmet Soy Æ Melek Ergin Æ Semra Paydas Lymphadenopathy in adult-onset Still’s disease mimicking peripheral T-cell lymphoma Received: 19 June 2003 / Accepted: 23 September 2003 / Published online: 20 December 2003 Ó Clinical Rheumatology 2003 Abstract Lymphadenopathy (LAP) that is seen in adult onset StillÕs disease (AOSD) may be confused with lymphoma. Here we present a patient with AOSD and with LAP that histopathologically mimicked T-cell lymphoma. Keywords Adult-onset StillÕs disease Æ Lymphadenopathy Abbreviations AOSD Adult-onset StillÕs disease Æ CRP C-reactive protein Æ ESR Erythrocyte sedimentation rate Æ LAP Lymphadenopathy Æ TGGE Temperature gradient gel electrophoresis Introduction Adult onset StillÕs disease (AOSD) is adult form of StillÕs disease seen in children and was been first described by Bywaters [1]. In addition to the classic findings, LAP and splenomegaly may occur [2]. LAP, both clinically and even sometimes histologically, may be confused with malignant lymphoma [3, 4, 5]. Here we present a patient with both AOSD and LAP histopathologically mimicking T-cell lymphoma. Case report A 20-year-old-man was admitted to our hospital because of the recent onset of fever of 39°C, and polyarticular arthritis. Physical examination showed a red-pink maculopapular rash on the trunk and upper extremities, arthritis of the knees, elbows, wrists and hands, multiple left cervical and axillary LAP that reached 2·2cm diameter in size, and splenomegaly. Erythrocyte sedimentation rate (ESR), CRP, hematocrit, MCV, leukocyte count and platelet count were 128 mm/h, 148 mg/dl [normal: 0–6], 26%, 80 fl, 15·109/l and 235·199/l, respectively. Peripheral blood smear revealed neutro- philia. The blood chemistry was normal except for a mild elevation in liver transaminases. ECG and chest X-ray were found to be normal. Ferritin level was extremely high, i.e. 29 000 ng/ml (nor- mal: 15–200), and b 2 -microglobin was 2240 ng/ml (normal: 660– 2740). Rheumatoid factor was positive at low titer and antinuclear antibody, anti-HIV1–2, anti-HCV, HbsAg and HBV- DNA were found to be negative. Except for mild splenomegaly and mesenteric LAP, thoracoabdominopelvic CT scans were normal. Axillary lymph node biopsy was performed to evaluate a malignant or infectious process. Histologically, three lymph nodes showed a mixture of small lymphocytes and a prominent expansion of immunoblasts and plasma cells. Immunoblasts had one or more nucleoli and mitoses (Fig. 1). The immunoblasts expressed UCHL- 1. The lymphoid activation marker CD30 was negative. CD68 was positive in histiocytes. Small lymphocytes were positive for CD20. Histological and immunohistochemical patterns resembled those of non-HodgkinÕs lymphoma, owing to the prominent immunoblast proliferation and frequent mitoses. Aspiration and biopsy of the bone marrow revealed no infiltration. Only non-steroid anti- inflammatory drugs were prescribed. The LAP regressed sponta- neously over a 2-week period. Because of discordance between the clinical course and histological findings, the lymph node biopsy was re-evaluated and some further molecular studies were performed. Discussion Sometimes it may be difficult to differentiate AOSD from malignant hematologic disorders [2]. In addition to clinical features, histopathological features of lymph node biopsy may also mimic lymphoma [5, 6, 7, 8, 9]. Even chemotherapy may be given to patients with a diagnosis of lymphoma, as reported by Korkmaz et al. [7]. On the other hand, malignant lymphoma has also been described in the course of AOSD, as seen in other rheumatologic disorders [10]. We performed Clin Rheumatol (2004) 23: 81–82 DOI 10.1007/s10067-003-0826-y M. Soy Department of Rheumatology, Trakya University Faculty of Medicine, Erdirne, Turkey M. Ergin (&) Department of Pathology, Cukurova University Faculty of Medicine, 01130 Balcali, Adana, Turkey E-mail: erginm@yahoo.com Tel.: +90-03223-386060/3158 Fax: +90-03223-386572 S. Paydas Department of Oncology, Cukurova University Faculty of Medicine, 01130 Balcali, Adana, Turkey