Recurrent Kikuchi's disease during pregnancy

Abstract

Kikuchi–Fujimoto disease (KFD) is a distinctive type of necrotizing lymphadenitis, has a self-limiting clinical course and usually affects the cervical lymph nodes of young women (1). The cervical lymphadenopathy may be tender and can be accompanied by fever and other upper respiratory tract symptoms (2). The etiology is still unknown. Although KFD occurs most often in young women, a review of the literature revealed that only two cases have been reported during pregnancy (3, 4). In one of these cases KFD initially developed 6 years before pregnancy (4). In this case study we present a 37-year-old woman who had recurrent KFD during pregnancy. A 37-year-old pregnant woman in her 20th week of gestation was admitted to our hospital with a 20-day history of swelling on the right side of her neck associated with a temperature ranging from 37.2 to 39.4 °C. On physical examination a 2 cm × 2 cm firm, tender lymph node in the posterior cervical triangle was palpable. The serum chemistry panel and chest radiography were normal. Investigations showed hemoglobin 9 g/dL, white cell count 1.8 × 109/L with normal differential count, platelets 190 × 109/L and erythrocyte sedimentation rate 104 mm/h. Tests for bacteria, fungi, parasites and viruses, as well as immunological studies for autoimmune diseases, were all negative. The enlarged cervical lymph node was excised for histological examination and a diagnosis of necrotizing-type KFD was made. The patient received no treatment and 6 weeks later she had no symptoms. She delivered a healthy boy and 18 months later mother and infant are in excellent condition. Her notes from 5 years ago indicated that she had presented with a similar clinical history. Lymph-node biopsy at that time showed “Kikuchi's disease of necrotizing type.” The patient received no treatment and 2 months later she had no symptoms. The lymph node excised was fragmented. There were large confluent areas of necrosis with substantial disturbance of the normal nodal architecture. Necrosis was extensive and karyorrhexis was prominent. No neutrophils, plasma cells or eosinophils were identified. There was a moderate number of blastic cells and a large number of mixed crescentic and nonphagocytic histiocytes (Fig. 1). Immunohistochemical studies were carried out for CD3, CD45RO, CD45, CD43, CD4, CD8, CD20 and CD68. A mixture of histiocytes and large T-lymphocytes was found in the necrotizing lesion, with histiocytes the predominant cells. On the basis of these findings the diagnosis of necrotizing-type KFD was made. Necrotizing-type KFD. High magnification showing the necrotic area with striking karyorrhexis and nonphagocytic histiocytes (hematoxylin–eosin stain; original magnification × 400). KFD was first recognized in Japan in 1972 (5) and subsequently reported in the West. Leukopenia and a high erythrocyte sedimentation rate were found in our case, similar to most of the reported cases (1, 2). Only very few patients would be expected to experience a recurrent attack; the recurrent rate of KFD has been reported to be approximately 3% (1). Although the differential diagnosis of KFD may include several non-neoplastic conditions, such as systemic lupus erythematosus, toxoplasmic lymphadenitis, infectious mononucleosis and cat-scratch disease, the difficulties and the importance of differentiating KFD from non-Hodgkin's lymphoma have been emphasized in some studies (2). The condition has characteristic morphological and immunohistochemical features to achieve the precise histological diagnosis, particularly when there is association with the correct clinical context. Although KFD occurs mainly in women of childbearing age, to the best of our knowledge only two cases of KFD have been reported to develop during pregnancy (3, 4). Mothers and children, as in our case, carried the infants to full term and were healthy after delivery. One of these cases was recurrent (4). In conclusion, this is the second reported case of recurrent KFD during pregnancy and the third case of KFD developing during pregnancy. We suggest that, if KFD occurs in a pregnant woman, there is no need to terminate the pregnancy, because it seems that there is no effect on either the pregnant woman or the fetus.