Kikuchi-Fujimoto disease (KFD) is a self-limiting, benign illness that is typified by cervical lymphadenopathy, typically accompanied by a low fever and night sweats. Loss of weight, nausea, vomiting, and sore throat are fewer common symptoms. KFD can have an acute or subacute start, and it usually develops over two to three weeks. Although viral aetiology is still a concept that needs further research, the clinical, histological, and immunohistochemical aspects seem to support it. Since specific diagnostic laboratory tests are not available, the diagnosis is frequently established by excising a sample of the affected lymph nodes. This case study features a 63-year-old male patient who first complained of fever and dyspnoea. Upon further investigation, the patient's condition was determined to be Kikuchi-Fujimoto disease, which was treated appropriately.

Immune checkpoint inhibitors have become one of the effective means of solid tumor treatment, among which anti-programmed death-1 (PD-1) antibodies are more maturely applied and can effectively inhibit tumor immune escape, thus enhancing the anti-tumor effect, but it can also lead to a series of immune-related adverse events (irAEs) in the process of clinical use. Here, we report a Patient with pancreatic solid pseudopapilloma treated with Sintilimab for the fifteenth cycles who developed chills, fever, and lymph node enlargement. Considering that the patient did not have infection, without history of autoimmune disease, we diagnosed the patient with Sintilimab-induced histiocytic necrotizing lymphadenitis (Kikuchi disease). The symptoms are alleviated after rapid use of glucocorticoids. Histiocytic necrotizing lymphadenitis (Kikuchi lymphadenitis) with anti-programmed death-1 (PD-1) antibody is a rare immune-related adverse events (irAEs).

Kikuchi's disease is an idiopathic self-limiting condition first reported in Japan in 1972. However, hemophagocytic lympho-histiocytosis is a condition that occurs due to overstimulation of the immune system. The presence of the two conditions is rare, and the clinical observation of this unusual clinical syndrome is worth reporting. We are reporting an 18-year-old Saudi female patient who presented with high-grade fever and diaphoresis 3 weeks before her presentation. Physical examination showed palpable cervical and axillary lymphadenopathy; laboratory investigation found neutropenia, a high lactate dehydrogenase of 550 U/L, and high ferritin levels. A thoracoabdominal computed tomographic study revealed generalized lymphadenopathy. She was diagnosed with hemophagocytic lympho-histiocytosis based on a bone marrow biopsy finding and Kikuchi's disease based on an excisional cervical lymph node biopsy. She received a high dose of dexamethasone with complete resolution of the condition. In conclusion, hemophagocytic lympho-histiocytosis and Kikuchi's Disease are uncommon conditions. The presence of a combination of such two conditions is extremely rare and worth reporting. Early diagnosis and initiation of the management with high dexamethasone dose could save patient life.

Hemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of widespread inflammation due to massive amounts of cytokines released from activated macrophages. The most common trigger for HLH is infection from a virus, most commonly Epstein-Barr virus. Here we report an adult case of this rare and life-threatening syndrome.

Kikuchi-Fujimoto disease (KFD) is an under-recognized disease most commonly presenting with cervical lymphadenopathy, fever, and cytopenias in young females. Bilateral parotid enlargement is usually caused by infections (e.g., mumps) and autoimmune conditions (e.g., Sjogren syndrome). Parotid enlargement, inguinal lymphadenopathy, and pyrexia of unknown origin are uncommon presenting features of KFD and should be suspected in the appropriate setting.

Kikuchi-Fujimoto disease (KFD) is a rare benign disorder predominantly affecting young adults and has a site predilection for cervical lymph nodes. The objective of this study is to analyze the clinicopathological features of KFD. A retrospective study of 24 cases of KFD presenting at a tertiary care hospital in southern India over a 4 year period is presented here. Clinical findings, histopathological findings and follow up data were reviewed. Of the 24 cases encountered, 17 were females and 7 were males. Painless cervical lymphadenopathy was the most common presenting feature. All cases showed typical morphology of KFD with necrosis, karyorrhectic debris and presence of the typical cell types namely crescentic histiocytes and plasmacytoid monocytes. Of the 19 cases with follow up, all resolved within 1 month. The pathologist should be aware of the typical presentation and morphology of KFD in order to distinguish it from the more common causes of cervical lymphadenopathy like tuberculosis (especially in countries like India) as well lymphomas.

Kikuchi-Fujimoto lymphadenitis is a self-limited disorder that typically presents in young females as painless cervical lymphadenopathy with fever, anemia, and leukopenia. The clinical manifestations and pathologic findings suggest a viral etiology, yet specific etiologic agents remain unknown. Although there are studies reporting positive associations between Kikuchi-Fujimoto lymphadenitis and parvovirus B19 and herpesviruses, other studies have failed to find an association with these viruses. To our knowledge, this current study is the largest study of Kikuchi-Fujimoto lymphadenitis in Western patients that used polymerase chain reaction testing for 4 different common viral pathogens often implicated as etiologic agents in Kikuchi-Fujimoto lymphadenitis. Archival material from 3 institutions was included, following confirmation of the diagnosis of Kikuchi-Fujimoto lymphadenitis by 2 independent pathologists. Polymerase chain reaction from the paraffin-embedded tissue sections for parvovirus B19, Epstein-Barr virus, human herpesvirus 6, and human herpesvirus 8 was performed. Eighteen cases of Kikuchi-Fujimoto lymphadenitis were analyzed, 12 of which (60%) were cervical lymph nodes. All the cases showed typical geographic necrosis with abundant apoptotic debris, although the degree of necrosis was variable. Polymerase chain reaction revealed a high prevalence of parvovirus B19 in the controls (44%); there were fewer positive cases seen in the Kikuchi-Fujimoto lymphadenitis cases (11%), but this did not reach statistical significance (P = .25).There were no significant differences between cases and controls in the prevalence of Epstein-Barr virus, human herpesvirus 6, and human herpesvirus 8 (P = .50 for all 3). Polymerase chain reaction failed to reveal a positive association between Kikuchi-Fujimoto lymphadenitis and 4 common suspected viral agents. These findings do not support a role for Epstein-Barr virus, human herpesvirus 6, human herpesvirus 8, or parvovirus B19 in the pathogenesis of Kikuchi-Fujimoto lymphadenitis.