Gabriel A. Bumanglag, MD | Azenith May H. Rafanan, MD | Monica N. Yu-Tolentino, MD
Background: Lymphoproliferative disorders can pose a diagnostic challenge due to its wide spectrum of diagnosis, and histomorphologically, may appear similar to a benign lesion and a lymphoma. Utilizing special stains, immunohistochemistry stains (IHS) and molecular studies are considered vital tools in arriving at an accurate diagnosis as it plays a major role in the management and prognosis of the patient. Case: The patient was a 30-year-old female presenting with one-month history of a tender right inguinal mass with no other associated signs and symptoms. Ultrasound findings in the pelvis was unremarkable. Excisional biopsy was done. Histopathologic Findings: Microscopic sections showed a paracortical lymph node expansion with patchy, circumscribed necrotic areas showing abundant karyorrhectic nuclear debris and histiocytes. No neutrophils or eosinophils were seen. Acid Fast Bacilli (Mycobacterium) special stain showed no organisms. IHS showed positive reactivity of peripheral T cells (CD3) and most B-cells (CD20). CD 68 reactivity confirmed the presence of abundant histiocytes. BCL-2, used to differentiate follicular hyperplasia from follicular lymphoma, showed negative reactivity in the germinal centers favoring a follicular hyperplasia. A diagnosis of Kikuchi- Fujimoto Disease (KFD) was made. Conclusion: KFD is a rare, benign, self-limiting disease of the lymph nodes that may affect all ages, both sexes, and different ethnic groups. The definitive diagnosis is carried out by excisional biopsy of the affected lymph node and utilizing immunohistochemistry and special stains to confirm the diagnosis. Although the disease follows a benign course, it persists from several weeks to months. Nonetheless the probability of recurrence or relapse is low. Although there is no definite regimen for KFD due to variation of etiologies, symptomatic management remains as the recommended treatment.