Distinguishing Kikuchi-Fujimoto disease from lymphoma in patients by clinical and PET/CT features

To develop a scheme for distinguishing Kikuchi-Fujimoto disease (KFD) from lymphoma in patients presenting enlarged lymph nodes (LNs) predominantly on the upper side of the diaphragm. From November 2015 to August 2023, 32 KFD patients and 38 lymphoma patients were pathologically confirmed and enrolled in this retrospectively study. Clinical and 18F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) features were collected. When comparing those PET/CT parameters, we set 5 models with different research objects: (1) all affected LNs; (2) the 5 largest affected LNs in terms of maximum diameter; (3) the 5 largest affected LNs in terms of maximum standard uptake values (SUVmax); (4) the largest affected LNs in terms of maximum diameter; (5) the largest affected LNs in terms of SUVmax. Compared to lymphoma patients, KFD patients were younger; and with higher incidence of fever, arthralgia, abnormal serum white blood cell, lactate dehydrogenase (LDH) and splenomegaly; lower incidence of affected LNs perinodal infiltration, necrosis and conglomeration; more affected LNs in Head and Neck nodes (particularly in level II) and Axillary in KFD (P ˂ .05). PET/CT parameters presented as various difference in each model. Finally, 11 clinical and PET/CT features (age ≤ 34, with fever, arthralgia, abnormal white blood cell, abnormal LDH, and without node necrosis and node conglomeration have a score of 2 each; splenomegaly, perinodal infiltration, median maximum diameter ≤ 20.5 and median SUVmax ≤ 7.1 of affected LNs in model 2 have score of 1 each) were selected as scheme items for distinguishing KFD from lymphoma. Individuals who have a total score > 8, meet the criteria for KFD. Sensitivity and specificity were high: 86.8% (95% CI: 71.9%, 95.5%) and 96.9% (95% CI: 83.7%, 99.5%), AUC = 0.975 (95% CI: 90.5%, 99.6%), respectively. It can effectively distinguish KFD from lymphoma by clinical and PET/CT parameters.

Kikuchi Cervical Lymphadenitis in Children: Ultrasound Differentiation From Common Infectious Lymphadenitis

OBJECTIVES

To investigate ultrasound (US) features of enlarged cervical lymph nodes (LNs) to differentiate between Kikuchi disease (KD) and other common types of infectious lymphadenitis in an East Asian pediatric patient population.

METHODS

A total of 142 pediatric patients with KD and 45 patients with infectious lymphadenitis (suppurative lymphadenitis [n = 29], nontuberculous mycobacterial lymphadenitis [n = 9], and tuberculous lymphadenitis [n = 7]) were included. The clinical characteristics, laboratory results, and US features of LNs were reviewed. The area under the curve (AUC) from a receiver operating characteristic curve analysis was used as a diagnostic accuracy measure.

RESULTS

A multiple clustered adjacent pattern, bilaterality, an even size, posterior neck involvement, no enlargement, an elongated-to-ovoid shape, homogeneous hypoechogenicity, a well-defined margin, presence of an echogenic fatty hilum, no intranodal gross necrosis, increased perinodal fat echogenicity, and no increased echogenicity of the adjacent sternocleidomastoid muscle were significant US features of the affected LNs to discriminate KD from infectious lymphadenitis (P < .05). Homogeneous hypoechogenicity in KD showed the highest AUC (0.930) as a single variable (95% confidence interval, 0.88-0.96). The AUCs were increased in 3 combination models with 2 US features: homogeneous echogenicity and 1 of 3 other US features (increased perinodal fat echogenicity, 0.935; number of affected LNs, 0.947; and LN shape, 0.949).

CONCLUSIONS

Homogeneous hypoechogenicity of LNs was a significant US feature with the highest diagnostic accuracy in differentiating KD from common infectious lymphadenitis on a univariate analysis. In the combination model, US features of an elongated-to-ovoid shape and homogeneous hypoechogenicity showed the highest diagnostic accuracy.

Analysis of the clinical manifestations and 18F-FDG PET-CT findings in 40 patients with histiocytic necrotizing lymphadenitis

Histiocytic necrotizing lymphadenitis (HNL) is a rare, benign, and self-limiting inflammatory disease that mainly involves the lymph nodes. There is a lack of large sample studies concerning the clinical manifestations and imaging features of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) of HNL.The clinical symptoms, laboratory examination results, 18F-FDG PET/CT imaging features, and treatment outcome were investigated in this retrospective study.A total of 40 HNL patients were recruited. The onset age was between 14 and 65 years, with a median of 25 years. The white blood cell count was 3.9 (2.9, 7.1) × 109/L, C-reactive protein level was 20.2 (6.6, 63.8) mg/L, erythrocyte sedimentation rate was 29.0 (18.0,45.0) mm/h, and ferritin was 616.5 (205.6, 2118.1) ng/mL. An abnormal liver function was observed in 23 patients. 18F-FDG PET-CT showed that an abnormal lymph node metabolism was observed in 38 patients, among which the highest 18F-FDG maximal standard uptake value (SUVmax) of the lymph nodes ranged between 3.4 and 41.9; the nodes were mainly distributed in the neck and axilla regions. Meanwhile, a total of 2502 lymph nodes (721 lymph nodes with a short axis greater than 10 mm) were found in the 38 patients, including 1837 lymph nodes with an 18F-FDG SUVmax ≥ 2.5. The 18F-FDG SUVmax of the spleen ranged from 2.5 to 9.2 in 20 patients, while that of central and peripheral bone marrow ranged from 2.7 to 36.0 in 30 patients. After follow-up for an average period of 1 month, the symptoms improved after prednisone treatment.HNL often occurs in adolescents. Scanning with 18F-FDG PET/CT showed that most patients had multiple involved lymph nodes that were hypermetabolic, and only few lymph nodes are enlarged. Besides, the spleen or central and peripheral bone marrow could sometimes be hypermetabolic. Glucocorticoid treatment for the HNL patients is effective.

CT pattern analysis of necrotizing and nonnecrotizing lymph nodes in Kikuchi disease

Objective

The purpose of this study was to determine whether a CT interpretation with imaging pattern analysis differentiates Kikuchi disease (KD) from the two more frequently encountered differential lymph nodes diagnoses of tuberculous lymphadenopathy (TL) and reactive hyperplasia (RH).

Materials and methods

Between January 2012 and July 2015, 20 patients with KD (6 men, 14 women; mean age, 27.80 years), 36 patients with RH (10 men, 26 women; mean age, 33.08 years) and 34 patients with TL (17 men, 17 women; mean age, 39.82 years) were pathologically diagnosed using US-guided fine needle aspiration biopsy, core needle biopsy, or surgical excisional biopsy. We recorded the total number, location, and size of the affected cervical lymph nodes, and two radiologists reviewed the characteristic imaging findings, including the presence of necrosis, cortical enhancement pattern, perinodal infiltration, conglomeration and nodal calcification, to form a consensus. In addition, we compared two attenuation indices on the nonnecrotic portion of the affected lymph nodes, nodal cortical attenuation (NCA) and the ratio of NCA to the adjacent muscle (NCA/M).

Results

Conglomeration, enhancement pattern and NCA/M values were independent predictive CT features to distinguish KD from RH. Age and enhancement pattern discriminated KD from TL. Only the mean NCA/M value was a statistically significant CT feature (p = .008) in differentiating KD from both RH+TL. The mean NCA/M of KD (1.67 ± 0.20) was significantly higher than that of RH (1.49 ± 0.20) or TL (1.47 ± 0.21).

Conclusion

Our results indicate that in case of nonnecrotic lymphadenopathy, a higher NCA/M index can differentiate KD from RH and TL. In addition, the enhancement pattern according to the degree of necrosis discriminated between KD and TL in the case of necrotic lymphadenopathy.

Role of Real-Time Elastography in the Evaluation of Cervical Lymph Nodes in Patients with Kikuchi Disease

The purpose of this study was to compare the use of conventional ultrasound (US) and real-time elastography (RTE) in Kikuchi disease (KD, n = 48) and malignant cervical lymphadenopathy (n = 100) and to evaluate the role of RTE in patients suspected of having KD. In univariate analysis, conventional US revealed each benign feature more frequently in KD than in malignant lymphadenopathy (p < 0.05). However, a considerable number of cases (29, 60.4%) of KD were assessed as malignant with US. KD was assessed as benign by RTE more frequently than malignant lymphadenopathy (37 [77.1%] vs. 37 [37.0%], p < 0.001). In multivariate analysis, perinodal hyper-echogenicity was predictive of KD (odds ratio: 67.25, confidence interval: 10.95-413.04, p < 0.001). There was a tendency for KD to be assessed as malignant with conventional US, but benign with RTE. RTE can help to avoid unnecessary biopsy in patients suspected of having KD on the basis of conventional US.

Real-time elastography of cervical lymph nodes in Kikuchi disease

We report, to our knowledge, the first cases of sonographic and real-time elastographic findings of cervical lymph nodes in patients with Kikuchi disease. Cervical lymph nodes had probably benign findings on grayscale sonography and real-time elastography.

Diagnosis of Kikuchi-Fujimoto disease: a comparison between open biopsy and minimally invasive ultrasound-guided core biopsy

Kikuchi-Fujimoto disease (KFD) is a self-limited disease without any need of surgical treatments. Sampling of tissue is the only invasive procedure during the clinical course. However, the standard sampling procedure with accuracy, minimal invasiveness, and esthetic maintenance has not been established yet. In this study, a retrospective review of clinical utility and pathological presentations of the ultrasound-guided core biopsy (USCB) and the open biopsy (OB) in consecutive KFD patients. From 2010 to 2012, 34 consecutive patients were enrolled. USCB was performed in 11 patients, and OB was done in 26 patients. KFD was confirmed in 82% cases by USCB. Similar pathological presentations were found both in the specimens of USCB and OB. In the three patients who had received both USCB and OB, KFD was confirmed by USCB in one case, while two by OB. Sampling errors were found both in USCB and OB. For diagnosing KFD, USCB can serve as the first-line diagnostic tool. OB can be applied only in the failed cases of USCB.

Features of sequential CT and US-guided biopsy in recurrent Kikuchi disease of the neck: a case report

A 26-year-old woman presented with recurrent Kikuchi disease 7 years after her initial episode. Computed tomography (CT) and ultrasonography demonstrated enlarged lymph nodes with extensive necrosis at the same site as the initial episode. Cytologic and histologic examinations were not conclusive. CT performed 1 month later demonstrated a complete resolution of the lymphadenopathy, which confirmed the diagnosis of recurrent Kikuchi disease. Care must be taken to avoid misdiagnosis of recurrent Kikuchi disease as tuberculous lymphadenitis.

[Histiocytic necrotizing lymphadenitis: (Kukuchi-Fujimoto disease): a diagnostic challenge]

Kikuchi-Fujimoto disease, also called Histiocytic necrotizing lymphadentis, is a rare, benign and self-limited disease, with unknown etiology, that affects mainly young women, and is characterized by adenopathy (usually localized in the cervical region) and fever. Diagnosis is based on histopathological findings in ganglionar tissue obtained in excisional biopsy, which allows, in most cases, the differential diagnosis with other similar clinical conditions, but which have a completely different clinical evolution and therapeutic needs. We report a case of a twenty four year old woman with persistent cervical lymphadenopathy, in which histopathological examination followed by immunohistochemical analysis of ganglionar tissue revealed to be Kikuchi-Fujimoto disease.

Gray scale and power Doppler study of biopsy-proven Kikuchi disease

OBJECTIVES

Kikuchi disease is a benign, self-limiting cause of cervical lymphadenopathy. It can show sonographic features similar to those of other common causes of lymphadenopathy. The purpose of this study was to characterize the sonographic features of Kikuchi disease that can contribute in differentiating between Kikuchi disease and other diseases causing cervical lymphadenopathy.

METHODS

Sonographic findings of 175 patients with biopsy-proven Kikuchi disease were retrospectively reviewed. The mean age of the patients was 27.3 years, and the female to male ratio was 3.5:1. All patients had undergone sonographically guided core biopsy. Pathologic findings were classified into proliferative (n = 57), necrotizing (n = 109), and xanthomatous (n = 9) types. On gray scale sonography, lymph nodes were assessed by their size, shape (shortest/longest axis ratio), location, echogenicity, presence of conglomeration, gross necrosis, calcification, echogenic nodal hilum, and increased perinodal echogenicity. The vascular pattern was assessed on power Doppler imaging.

RESULTS

The mean maximum diameter of the lymph nodes was 1.6 cm. Forty-four percent of them (77 of 175) were oval (shortest/longest axis ratio, 0.5-0.7) and 48% (84 of 175) were elongated (shortest/longest axis ratio, <0.5). Most were located in levels II and V. Seventeen lymph nodes showed gross necrosis, and none showed calcification. One hundred fifty-two lymph nodes (86.8%) had an echogenic hilum, and 76% (133 of 175) showed increased perinodal echogenicity. Increased perinodal echogenicity was seen in 93.5% of the necrotizing type (102 of 109) and 43.8% of the proliferative type (25 of 57); the difference between the two types was statistically significant (P = .001). Normal (n = 161), displaced (n = 13), and absent (n = 1) hilar vascularity was seen on power Doppler studies.

CONCLUSIONS

Sonographic findings of Kikuchi disease can contribute to the differentiation between Kikuchi disease and other causes of cervical lymphadenopathy.

Severe Kikuchi's disease responsive to immune modulation

Kikuchi's disease, although an uncommon entity, has been increasingly reported since it was first discovered in 1972. The most common manifestation of Kikuchi's disease, cervical lymphadenopathy, has no clinically distinguishable features. Therefore, a diagnosis of Kikuchi's disease has largely been based on clinical suspicion and histopathological confirmation. We present a 15-year-old Chinese girl with severe Kikuchi's disease, whose relapsing course was only responsive to highdose steroid and intravenous immunoglobulin therapy.

Kikuchi's disease in children: clinical manifestations and imaging features

Previously published studies on Kikuchi disease (KD) have frequently addressed the computed tomography (CT) findings in the adult population, however, only a few studies have been reported for the pediatric age group. The purpose of this study is to analyze the clinical characteristics and imaging features of KD in children. Fifteen children (2-14 yr) who had a neck CT and pathology diagnosis of KD were included in this study. Clinical features, including the duration of lymphadenopathy and fever, prognosis, and laboratory values, were evaluated. We analyzed the sites, size, and lymph node pattern as seen on their CT scans. The median duration of fever was 10 days. Fourteen patients experienced improvement in their condition, although four of these patients experienced recurrent episodes of KD. All patients had affected cervical nodes at level V. Perinodal infiltrates were observed in the affected cervical nodes in 14 cases (93%), and non-enhancing necrosis was also noted within the affected cervical nodes in 10 cases (63%). In conclusion, the combination of imaging findings in conjunction with clinical findings of KD may help to determine whether or not to perform pathology analysis and follow-up studies.

Kikuchi's disease with systemic manifestations: a link to the Epstein-Barr virus

Kikuchi's disease is a rare benign disease that presents with fever and cervical lymphadenopathy. The importance of this disorder, lies in distinguishing it from more sinister disorders, such as lymphoma, in order to avoid unnecessary investigation and treatment. Systemic manifestations are rare in Kikuchi's disease but are not unknown. We present two cases of varying degrees of systemic involvement due to Kikuchi's disease. Both these patients, a 22-year-old woman and a 44-year-old woman, were also found to have evidence of recent Epstein-Barr virus (EBV) infection. The evidence of a causative role for EBV in Kikuchi's is also reviewed.

Necrotizing lymphadenitis of the neck

Necrotizing lymphadenitis of the neck. Histiocytic necrotizing lymphadenitis is a rare cause of cervical lymphadenopathy. It is a benign, self-limiting disease whose etiology is unknown. Cervical lymphadenopathy and fever are the most important signs. Here we report a 25-year-old female presenting with complaints of fever and a painless swelling in the neck for three months. An excisional biopsy of a posterior cervical lymph node was performed, and histological evaluation revealed histiocytic necrotizing lymphadenitis. This article discusses our case of histiocytic necrotizing lymphadenitis of the neck as well as the relevant literature.

[Systemic lupus erythematosus and Kikuchi-Fujimoto disease mimicking tuberculosis]

Kikuchi-Fujimoto's disease (KFD) or histiocytic narcotising lymphadenitis is a febrile benign lymphadenopathy of unknown etiology, involving more frequently cervical lymph nodes and diagnosed on biopsy of an affected node. It is sometimes associated with auto-immune diseases such as systemic lupus erythematosus (SLE). However less frequent symptoms including involvement of extracervical nodes, hepatosplenomegaly and systemic symptoms (weight loss, night sweats) are possible and suggest an infectious disease. We report the case of a Senegalese patient with positive Ag HBs who developed SLE and KFD mimicking tuberculosis. Atypical pseudo-infectious appearance of an inflammatory systemic disease is a rare occurrence and the diagnosis can be difficult.

Cervical lymphadenopathy secondary to Kikuchi-Fujimoto disease in a child: case report

While most cases of cervical lymphadenopathy resolve with conservative management, persistent adenopathy can lead to costly investigations and invasive treatments. One cause of persistent adenopathy, as well as a variety of other associated systemic symptoms, is Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenitis). This rare entity can be diagnosed only by excisional biopsy on the basis of its characteristic histologic appearance. We describe a case of persistent cervical lymphadenopathy secondary to Kikuchi-Fujimoto disease in an 11-year-old girl.

Sonographic features of axillary lymphadenopathy caused by Kikuchi disease

OBJECTIVE

The purpose of this study was to document the sonographic findings of axillary lymphadenopathy in Kikuchi disease.

METHODS

The medical records and sonographic findings of 7 patients with a pathologic diagnosis of Kikuchi disease in the axillary lymph node by sonographically guided core needle biopsy (n=6) or excisional biopsy (n=1) were reviewed. On sonograms, lymph nodes were assessed for their distribution, size, shape, border, echogenicity, and internal architecture, and those sonographic features of each node were evaluated to determine whether the findings favored malignant or benign lymphadenopathy.

RESULTS

Of the 7 patients (1 man and 6 women; mean age +/- SD, 34.3+/-7.7 years), 29 affected lymph nodes (5-38 mm; mean, 14.8+/-7.2 mm) were identified on sonograms. The sonographic characteristics were as follows: the shortest axis/longest axis ratio of the node (mean, 0.595) was 0.5 or greater in 22 nodes (76%); the border was sharp in 16 (55%); the cortex was hypoechoic in 20 (69%) and isoechoic in 9 (31%); the hilum was narrow in 1 (4%) and absent in 16 (55%); and cortical thickening was found in 13 (45%, concentric in 6 and eccentric in 7). Nineteen lymph nodes (66%) were classified as having malignant-favoring features, and 10 (34%) were classified as having benign-favoring features.

CONCLUSIONS

Many axillary lymph nodes in Kikuchi disease look suspicious sonographically. When lymph nodes in the axilla show suspicious findings on sonograms of relatively young patients, Kikuchi disease can be considered a possible differential diagnosis, and image-guided percutaneous biopsy should be done.

Tuberculosis mimicking Kikuchi's disease

Kikuchi's disease is an idiopathic self-limiting necrotizing lymphadenitis. Clinically, it mimics tuberculous cervical lymphadenopathy. The disease is diagnosed by histopathologic study. The only specific treatment that has been reported is empiric steroid therapy. We report a case of tuberculosis that was originally thought to be Kikuchi's disease in a 24-year-old man. When the patient's condition worsened during a course of steroid therapy, he underwent surgical exploration, which revealed the presence of tuberculous lymphadenitis. The patient was switched to antituberculosis drug therapy, and his improvement was dramatic.

[Kikuchi-Fujimoto disease mimicking thyroid metastasis]

INTRODUCTION

Kikuchi-Fujimoto lymphadenopathy is a subacute necrotizing lymphadenopathy of unknown origin. It usually affects cervical lymph nodes. Lymph node biopsy is needed for establishing the diagnosis. This disease must be considered as a possible cause of lymphadenopathy of unknown origin, certainly if classical clinical features lead to diagnostic confusion.

OBSERVATION

A 41-year-old female presented a thyroid cancer treated by thyroidectomy associated with administration of I131. She also presented a right cervical metastasis treated by surgery. She had a cervical right cervical lymphadenopathy, hypermetabolic on the FDG scan, treated by a modified neck dissection. Microscopy of the surgical specimen showed necroziting lymphadenitis.

DISCUSSION

Kikuchi-Fujimoto lymphadenopathy is a subacute necroziting lymphadenopathy of unknown origin, involved more commonly cervical lymph nodes unilaterally. It is more common in Asia, predominantly in young women. This lesion has been reported in patients of virtually any age or gender. No specific biological findings have been described. Lymph node biopsy is needed for establishing the diagnosis. The spontaneous course is usually favorable but one fatal case has been reported.

Intraparotid Kikuchi-Fujimoto disease masquerading as a parotid gland tumor

The Kikuchi-Fujimoto disease, also known as histiocytic necrotizing lymphadenitis, is a self-limiting lesion of unknown cause first described in 1972 independently by Kikuchi and Fujimoto et al. This self-limiting disorder usually occurs in Asian women in their late 20s or early 30s. Typically, it runs a benign course and appears to resolve spontaneously 1 to 6 months after definite diagnosis. The Kikuchi-Fujimoto disease usually manifests as a localized cervical lymphadenopathy; therefore, most patients with this disease are seen in ears, nose, and throat practice. Nodal involvement other than in the neck area or extranodal involvement is rare. In this situation, however, the Kikuchi-Fujimoto disease is easily confused with other less-benign conditions. We describe a case of Kikuchi-Fujimoto disease in a 30-year-old man that presented as a parotid gland tumor. This is the third study to document intraparotid Kikuchi-Fujimoto disease in the English literature. Our report illustrates the clinical features of this unusual condition and emphasizes potential confusion with other diagnoses.

CT findings in Kikuchi disease: analysis of 96 cases

BACKGROUND AND PURPOSE

Although CT findings of Kikuchi disease (KD), or histiocytic necrotizing lymphadenitis, are reported in several case reports, large-scale analysis of the disease has not been undertaken. We characterized the clinical and CT findings in a large group of patients with KD.

METHODS

Between 1990 and 2002, 96 patients (68 women, 28 men; mean age, 24.4 years) underwent biopsy of the cervical lymph nodes and had histologically proved KD at our institution. We reviewed their clinical and CT findings and recorded the total number of affected nodes; location and size of the lymph nodes; and characteristic findings including necrosis, perinodal infiltration, and contrast enhancement.

RESULTS

We identified 1196 affected lymph nodes (12.5 nodes per patient). The affected lymph nodes were 0.5-3.5 cm (mean, 1.62 cm). Perinodal infiltration was found in 78 patients (81.3%). Eighty (83.3%) had homogeneous nodal contrast enhancement. Nine patients (9.4%) had lymph nodes with a focal low attenuation, and seven (7.3%) had ring-shaped lymph nodes. Unilateral and bilateral cervical lymph nodes were affected in 76 and 20 patients, respectively. Lymph nodes were mainly located at levels II (IIA, 174 nodes; IIB, 254 nodes), III (222 nodes), IV (160 nodes), and V (VA 126 nodes, VB 130 nodes). Follow-up CT in 32 patients showed complete resolution in 14 and partially improved lymphadenopathy in 18.

CONCLUSION

Awareness of the various CT appearances of KD and follow-up CT may be helpful for more accurate diagnosis of the disease.

Grey-scale and power Doppler sonography of unusual cervical lymphadenopathy

This study was undertaken to document the grey-scale and power Doppler sonographic features of cervical lymphadenopathy in Kikuchi's disease (histiocytic necrotising lymphadenitis), Rosai-Dorfman disease (sinus histiocytosis with massive lymphadenopathy), Sjogren's syndrome and systemic lupus erythematosus (SLE), which have not been reported in the literature. A retrospective review of the grey-scale and power Doppler sonograms of the cervical lymph nodes in nine patients was conducted (Kikuchi's disease, n = 3; Rosai-Dorfman disease, n = 1; Sjogren's syndrome, n = 1; SLE, n = 4). Lymph nodes were proven to be pathologic by fine-needle aspiration cytology (FNAC). On grey-scale ultrasound (US), lymph nodes were assessed by their distribution, size, shape, echogenicity and internal architecture. The vascular pattern of the lymph nodes was assessed with power Doppler sonography. US features of the lymph nodes were compared to those of metastatic and reactive nodes. In Kikuchi's disease, Rosai-Dorfman disease, Sjogren's syndrome and SLE, the distribution of lymph nodes is similar to that of reactive nodes. Most of the lymph nodes are enlarged with a maximum transverse diameter greater than or equal to 10 mm (83.3 to 100%). In Kikuchi's disease, lymph nodes have grey-scale and Doppler appearances similar to reactive nodes. However, lymph nodes in Rosai-Dorfman disease, Sjogren's syndrome and SLE show similar grey-scale and Doppler features to metastatic nodes. There is no specific US feature to characterise lymphadenopathy from these four miscellaneous causes. Definitive diagnosis should still be based on cytology and histology, and US can help in guiding FNAC for a more accurate cytologic examination.

[Histiocytic necrotizing lymphadenitis or Kikuchi's disease. CT radiologic features]

Histiocytic necrotizing lymphadenitis, Kikuchi Fujimoto's disease (KFD) is characterised by fever and lymphadenopathy, usually large cervical, unilateral lymph nodes. Such clinical presentation demands a work-up to exclude serious medical conditions like malignancy and infections. Foci of necrosis with lymphocytic Histiocytic predominance in association with scarce polymorphonuclear cells on lymph node examination, confirm the diagnosis of KFD. Many different patterns of computed tomographic (CT) appearance of KFD have been reported. We describe the CT scan finding in two patients with this disease. All our cases showed, after two and three weeks of evolution respectively, enlarged lymph nodes with hypodense centres and peripheral ring enhancement. These radiological alterations correlated with the central lymph node necrosis found in the anatomopathological studies. In conclusion, KFD should be considered in patients with fever, cervical lymph node enlargement and CT scan showing hypointense centres and peripheral ring enhancement.

Cross-sectional imaging of Kikuchi disease

PURPOSE

The purpose of this work was to characterize the cross-sectional imaging features of Kikuchi disease.

METHOD

A search of our hospital records yielded three patients with pathologically proven Kikuchi disease. CT, MR, and ultrasound examinations of these patients were reviewed to characterize the imaging features of Kikuchi disease.

RESULTS

MRI of the neck in one patient, CT of the chest and abdomen in another, and CT and MRI of the abdomen in the third demonstrated uniformly enhancing small lymph nodes in larger than normal numbers in the submandibular, axillary, gastrohepatic, celiac, periportal, paraaortic, retrocrural, mesenteric, and inguinal regions. Lymph node diameter was usually <10 mm and was always <18 mm.

CONCLUSION

Many small clustered lymph nodes may be a characteristic imaging feature of Kikuchi disease. The abdominal extent of disease may be underreported if cross-sectional imaging is not performed.