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

Serum Alkaline Phosphatase Levels in Pediatric Kikuchi-Fujimoto Disease: A Retrospective Observational Analysis

AIM

Kikuchi-Fujimoto disease (KFD) rarely affects pediatric patients and is characterized by prolonged fever and cervical lymphadenopathy. The diagnosis of KFD remains challenging and often requires an invasive biopsy. Low serum alkaline phosphatase levels have frequently been observed in patients with KFD; however, the clinical significance of low serum alkaline phosphatase levels remains unclear.

METHODS

This retrospective study included pediatric patients aged < 16 years who were pathologically or clinically diagnosed with KFD and infectious mononucleosis between April 2016 and March 2023. Serum alkaline phosphatase levels were analyzed employing age- and sex-specific reference intervals. Clinical and laboratory data were evaluated to determine their association with serum alkaline phosphatase levels.

RESULTS

Thirty patients with KFD and 23 patients with infectious mononucleosis were included in the study. Seventeen patients with KFD (56.7%) had serum alkaline phosphatase levels below the 2.5th percentile of the age- and sex-specific reference intervals. Serum alkaline phosphatase levels were significantly lower in patients with KFD than in those with infectious mononucleosis. Clinical and other laboratory findings were not significantly different between patients with KFD with or without a decline in serum alkaline phosphatase levels.

CONCLUSION

A decrease in serum alkaline phosphatase levels, particularly when assessed as a percentage of age- and sex-specific reference intervals, may be a valuable and noninvasive supportive feature of KFD in pediatric patients.

Necrosis in lymph nodes and their differential diagnoses: application of reticulin staining

This study aimed to enhance the histopathological diagnosis of necrotic lymph node specimens. A chart review was conducted, revealing that the most common causes of lymph node necrosis were Kikuchi disease (33%), granulomatous inflammation (25%), metastasis (17%), and lymphomas (12%). Histological analysis of necrotic tissue in 333 specimens demonstrated significant differences between the four diseases. The necrotic tissue of Kikuchi disease was amorphous, and hypercellular, and exhibited karyorrhexis and congestion. Granulomatous inflammation presented amorphous necrotic tissue with a nodular-like pattern. Metastasis exhibited heterogeneous morphology that varied between cancer types. Lymphomas displayed extensive necrosis with ghost cells, congestion, and bubbles. Reticulin staining patterns also differed between diseases. Kikuchi disease and lymphomas exhibited preserved reticular fiber networks in the necrotic tissue, resembling the viable tissue. Granulomatous inflammation and metastasis showed disrupted reticular fiber networks in the necrotic tissue. Based on these findings, histological features and reticulin staining patterns can aid in diagnosing Kikuchi disease, granulomatous inflammation, metastasis, and lymphomas in necrotic lymph node specimens.

Application of ultrasound in distinguishing the incipient microtumor from inherent lymph nodes of the parotid glands

BACKGROUND

Parotid microtumors (size ≤ 1 cm) pose a significant clinical challenge due to their malignant potential and risks associated with surgery. It is imperative to explore the diagnostic workflow that incorporates ultrasound (US) in order to make appropriate clinical decisions with minimal invasiveness.

METHODS

The patients receiving both US and ultrasound-guided fine needle aspiration (USFNA) for the parotid microtumors in a medical center were retrospectively recruited. The ultrasonic features, cytology of USFNA, and final surgical pathology were analyzed to differentiate the tumor origins and their malignant potential.

RESULTS

From August 2009 to March 2016, a total of 92 patients were enrolled in the study. The short axis, long-to-short axis ratio, and presence of an echogenic hilum were found to be significantly useful in distinguishing lymphoid tissue origin from salivary gland origin, which was confirmed by USFNA. An irregular border was predictive for malignant parotid microtumors from both origins. Intra-tumoral heterogeneity was also identified as a significant feature associated with malignant lymph nodes. USFNA was able to confirm all malignant lymph nodes, but it had a false negative rate of 8.5% in parotid microtumors of salivary gland origin. Based on the analysis of US and USFNA results, a diagnostic workflow for parotid microtumors was proposed.

CONCLUSION

US and USFNA can be helpful in classifying the origins of parotid microtumors. US-FNA carries the risk of producing false negative results specifically for microtumors originating from salivary glands, but not lymphoid tissue. The diagnostic workflow, which incorporates both US and USFNA, assists in determining the clinical decision for diagnosing and managing parotid microtumors.

Kikuchi-Fujimoto Disease: A Case of Febrile Cervical Lymphadenopathy With Hematological Abnormalities

Kikuchi-Fujimoto disease (KFD), or histiocytic necrotizing lymphadenitis, is a benign but rare disorder associated with febrile cervical lymphadenopathy in young adults. Here, we discuss a case of a young female patient presenting with left tender cervical lymphadenopathy that progressed bilaterally with a fever of unknown origin. Laboratory parameters showed persistent leukopenia, especially neutropenia, which fluctuated with the degree of symptom severity. Two months were taken to confirm the diagnosis of KFD based on the histological interpretation of the lymph node biopsy. Supportive management with analgesics and paracetamol formed the main treatment. This case highlights the challenges and importance of diagnosing KFD to exclude other serious conditions such as lymphoma, tuberculosis, or lupus lymphadenitis that share similar clinical manifestations as KFD.

Histology-based and cytology-based needle sampling for targeted next-generation sequencing in the indeterminate thyroid tumors

PURPOSE

To establish the optimal and minimally invasive diagnostic approach for targeted next-generation sequencing (NGS) in the indeterminate thyroid tumors.

METHODS

The patients with indeterminate thyroid tumors were prospectively recruited and analyzed in a single tertiary medical center. We performed FNA and core needle biopsy (CNB) at the surgical specimens to confirm the quality of each sampling procedure. Cytological diagnosis by FNA, histological diagnosis by CNB and confirmed diagnosis by final surgery were compared to demonstrate the agreement among these approaches for the indeterminate thyroid tumors. The quality of the samples from FNA and CNB was evaluated, respectively to determine the optimal approach for targeted NGS. Finally, we performed ultrasound-guided CNB and FNA (US-CNB and US-FNA) on one case to confirm the clinical feasibility of being a pre-operative minimally invasive diagnostic approach.

RESULTS

A total of 6 female patients (average age: 50.83 ± 15.18 years) with indeterminate thyroid tumors (average size: 1.79 ± 0.91 cm) were recruited for further analyses. The pathological diagnoses could be obtained by CNB in the first five cases, and the sample quality of CNB for targeted NGS was better than that of FNA, even after 10X dilution. The gene mutations associated with thyroid malignancy could be detected by NGS. In the case treated with US-CNB, the pathological and targeted NGS results were successfully obtained, which suggested the possibility of thyroid malignancy to facilitate immediate decision of subsequent treatment.

CONCLUSION

CNB could serve as a minimally invasive diagnostic approach in the indeterminate thyroid tumors by providing pathological diagnoses and qualified samples for detection of mutated genes, which facilitates appropriate and immediate management.

Incorporation of ultrasound-guided core biopsy with flow cytometry to assist the diagnosis of cervical lymphoma

PURPOSE

The main purpose of surgery for cervical lymphoma is only for tissue sampling. To establish a patient-friendly diagnostic approach, we investigated the feasibility of ultrasound-guided core biopsy with flow cytometry in the patients with suspected cervical lymphoma.

METHODS

We prospectively recruited patients with suspected cervical lymphoma from Nov 2017 till Jan 2021 in a referral medical center and performed retrospective interpretation of the prospectively acquired data. Ultrasound-guided core biopsy as the tissue sampling approach for the targeted lesions was performed in all patients. The ultrasound-guided core biopsy samples were analyzed by immunohistochemical stains and flow cytometry. The sample quality and the rate of definite and decisive diagnosis obtained by ultrasound-guided core biopsy alone and ultrasound-guided core biopsy with flow cytometry were evaluated.

RESULTS

Total 81 consecutive patients were recruited for analysis. All ultrasound-guided core biopsy samples were qualified for analysis of pathology and flow cytometry. Pathologically, the diagnoses were definite and compatible with their flow cytometry results in 70 patients (86.42%). Either newly-diagnosed or recurrent cervical lymphoma/lymphoproliferative disorders with histologic transformation could be diagnosed by ultrasound-guided core biopsy with flow cytometry. Nine of the 11 patients with pathologically indefinite diagnosis became clinically decisive when flow cytometry was incorporated into the process, which improved the rate of decisive diagnosis to 98.77% (Odds ratio [95% CI]: 6.21 [1.28, 58.96]).

CONCLUSION

Ultrasound-guided core biopsy combined with flow cytometry is suggested to serve as the first-line and patient-friendly diagnostic approach for the patients with suspected cervical lymphoma.

All necrotizing nodes are not tuberculosis - A report of two cases

INTRODUCTION

Kikuchi-Fujimoto disease is a benign and self-limiting systemic disorder of unknown aetiology characterised by fever, superficial lymphadenopathy and leukopenia. In highly endemic & low-resource country like India, it is frequently misdiagnosed as tuberculosis.

CASE REPORT

Both the cases were diagnosed as necrotizing lymphadenitis by fine-needle aspiration cytology. Tuberculin skin prick test (TST) was positive for one case and negative for the other case. Cartridge based nucleic acid amplification test (CBNAAT) from lymph node aspirate was negative for mycobacterium tuberculosis in both the cases, later on histopathology of lymph node showed diagnosis of Kikuchi-Fujimoto disease.

CONCLUSION

Kikuchi Fujimoto is a self-limiting disease systemic disease of unknown aetiology. A definite diagnosis can be established by incisional/excisional biopsy of the lymph node. When dealing with cases of tubercular lymphadenitis, Kikuchi-Fujimoto disease should be kept as differential diagnosis.

Distinguishing lupus lymphadenitis from Kikuchi disease based on clinicopathological features and C4d immunohistochemistry

OBJECTIVES

Distinguishing Kikuchi disease (KD) from lupus lymphadenitis (LL) histologically is nearly impossible. We applied C4d immunohistochemical (IHC) stain to develop diagnostic tools.

METHODS

We retrospectively investigated clinicopathological features and C4d IHC staining in an LL-enriched development cohort (19 LL and 81 KD specimens), proposed risk stratification criteria and trained machine learning models, and validated them in an external cohort (2 LL and 55 KD specimens).

RESULTS

Clinically, we observed that LL was associated with an older average age (33 vs 25 years; P=0.005), higher proportion of biopsy sites other than the neck [4/19 (21%) vs 1/81 (1%); P=0.004], and higher proportion of generalized lymphadenopathy compared with KD [9/16 (56%) vs 7/31 (23%); P=0.028]. Histologically, LL involved a larger tissue area than KD did (P=0.006). LL specimens exhibited more frequent interfollicular pattern [5/19 (26%) vs 3/81 (4%); P=0.001] and plasma cell infiltrates (P=0.002), and less frequent histiocytic infiltrates in the necrotic area (P=0.030). Xanthomatous infiltrates were noted in 6/19 (32%) LL specimens. Immunohistochemically, C4d endothelial staining in the necrotic area [11/17 (65%) vs 2/62 (3%); P<10-7], and capillaries/venules [5/19 (26%) vs 7/81 (9%); P=0.048] and trabecular/hilar vessels [11/18 (61%) vs 8/81 (10%); P<10-4] in the viable area was more common in LL. During validation, both the risk stratification criteria and machine learning models were superior to conventional histological criteria.

CONCLUSIONS

Integrating clinicopathological and C4d findings could distinguish LL from KD.

Kikuchi-Fujimoto disease involving retroperitoneal lymph nodes: An uncommon presentation

Kikuchi-Fujimoto disease is a self-limited disease of unknown etiology that is clinically defined by fevers accompanied by tender posterior cervical lymphadenopathy. It often presents acutely or sub-acutely, and due to its non-specific features, the differential diagnosis is broad and includes infectious, autoimmune, and malignant causes. Although cases of extra-cervical disease are not uncommon, involvement of retroperitoneal lymph nodes has only rarely been reported. Here, we describe a patient with Kikuchi-Fujimoto disease who presented with fever of unknown origin, abdominal pain, and enlarged hypermetabolic retroperitoneal lymph nodes.

Efficacy of Ultrasound-Guided Needle Biopsy in the Diagnosis of Kikuchi-Fujimoto Disease

OBJECTIVES/HYPOTHESIS

Ultrasound-guided fine-needle aspiration cytology (US-FNAC) is a well-established procedure performed to establish the diagnosis of Kikuchi-Fujimoto disease (KFD). Ultrasound-guided core needle biopsy (US-CNB) is an alternative diagnostic tool for KFD. However, the efficacy of US-CNB is not well evaluated. This study aimed to evaluate the efficacy of US-CNB and compare it with that of US-FNAC in the diagnosis of KFD.

STUDY DESIGN

Retrospective cohort study.

METHODS

We analyzed 170 patients who were diagnosed with KFD between January 2009 and May 2019. US-FNAC, US-CNB, and excisional biopsy were performed in 47, 114, and 9 patients, respectively. Diagnostic accuracies of US-FNAC and US-CNB were analyzed and compared.

RESULTS

Of the 170 patients, 45 and 125 were men and women, respectively. The mean age was 26.9 ± 9.1 years. The most common symptom was cervical lymphadenopathy, followed by fever, headache, and myalgia. The diagnosis of KFD was established primarily by US-FNAC in 21 (44.7%) of the 47 patients, by US-CNB in 109 (95.6%) of the 114 patients, and by excisional biopsy in all 9 patients. There was no specific major complication related to US-FNAC and US-CNB.

CONCLUSION

US-CNB can be considered safe and effective and used as the primary modality for the pathological diagnosis of KFD.

LEVEL OF EVIDENCE

4. Laryngoscope, 131:E1519-E1523, 2021.

Kikuchi-Fujimoto disease in the regional lymph nodes with node metastasis in a patient with tongue cancer: A case report and literature review

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare self-limiting disorder typically affecting the cervical lymph nodes (LNs), which is often misdiagnosed as other LN-associated diseases. KFD frequently presents with necrotic lesions and recurrences, which are also features of metastatic LNs. Clinicians may thus suspect LN metastasis when they encounter ipsilateral cervical lymphadenopathy in a patient with head and neck cancer. The present study reports the case of a 48-year-old man with tongue cancer and KFD affecting the right edge of his tongue and ipsilateral cervical LNs. LN metastasis was initially suspected, but pathological examination of the dissected LNs revealed one necrotic metastatic lesion and two necrotic KFD lesions. Ipsilateral cervical lymphadenopathy recurred 6 years after the initial surgery, and it was not possible to differentiate clinically between a second primary tumor and recurrent KFD prior to treatment. To the best of our knowledge, this is the first reported case of simultaneous tongue cancer, regional LN metastasis and KFD. This highlights the requirement to consider KFD in the event of LNs with necrotic lesions but no cancerous cells. A combination of clinical and pathological approaches may aid in the diagnosis of KFD, in addition to ruling out LN metastasis in initial and recurrent lymphadenopathies. The present study indicate that a diagnosis of KFD should be considered in patients with head and neck cancer that exhibit necrotic LNs lacking cancerous cells. This is important, as misdiagnosis of KFD as LN metastasis may lead to unnecessary adjuvant therapy.

A white man with Kikuchi-Fujimoto disease mimicking lymphoma, preceded by frequent episodes of tonsillitis: a case report

Background

Kikuchi-Fujimoto disease is a very rare cause of benign lymphadenopathy affecting mainly young Asiatic females. Little is known about the causative agent of Kikuchi-Fujimoto disease; however, there are hypotheses of infectious, autoimmune, or hyperimmune background of the disease that have not yet been confirmed in the conducted studies. Frequent episodes of tonsillitis preceding the onset of Kikuchi-Fujimoto disease have not been described as yet.

Case presentation

A 23-year-old white man with a history of over 20 episodes of tonsillitis in the preceding 2 years was admitted to our hospital because of cervical unilateral lymphadenopathy, fever, night sweating, weight loss, and fatigue. On admission, slight tenderness of cervical lymph nodes and asymmetric palate tonsil enlargement were noted. Owing to the patient’s general symptoms and history of malignancy in his close family, a malignant disease such as lymphoma was suspected. Histopathological examination of the excised lymph node revealed areas of coagulative necrosis with abundant karyorrhectic debris, with histiocytes and lymphocytes observed at the margins of the necrotic areas. The microscopic examination led to an unexpected diagnosis of Kikuchi-Fujimoto disease. The patient was treated symptomatically. All of the patient’s symptoms, excluding tonsil enlargement, retreated within 2 months.

Conclusions

In the differential diagnosis of cervical lymphadenopathy in patients with frequent episodes of tonsillitis, Kikuchi-Fujimoto disease should be taken into account. Kikuchi-Fujimoto disease may convincingly mimic symptoms characteristic of lymphoma.

Kikuchi-Fujimoto disease: a diagnostic dilemma

Kikuchi-Fujimoto disease is a benign, self-limiting condition characterized by lymphadenopathy and fever. Its diagnosis can be challenging, as the disease must be differentiated from lymphoma and systemic lupus erythematosus. Patients can present with nonspecific cutaneous lesions. Adequate clinical and histopathologic correlation can aid in the timely diagnosis of Kikuchi's disease, thus preventing the use of unnecessary diagnostic procedures and inappropriate treatments.

Application of Ultrasound-Guided Core Biopsy to Minimal-Invasively Diagnose Supraclavicular Fossa Tumors and Minimize the Requirement of Invasive Diagnostic Surgery

Tumors of the supraclavicular fossa (SC) is clinically challenging because of anatomical complexity and tumor pathological diversity. Because of varied diseases entities and treatment choices of SC tumors, making the accurate decision among numerous differential diagnoses is imperative. Sampling by open biopsy (OB) remains the standard procedure for pathological confirmation. However, complicated anatomical structures of SC always render surgical intervention difficult to perform. Ultrasound-guided core biopsy (USCB) is a minimally invasive and office-based procedure for tissue sampling widely applied in many diseases of head and neck. This study aims to evaluate the clinical efficacy and utility of using USCB as the sampling method of SC tumors. From 2009 to 2014, consecutive patients who presented clinical symptoms and signs of supraclavicular tumors and were scheduled to receive sampling procedures for diagnostic confirmation were recruited. The patients received USCB or OB respectively in the initial tissue sampling. The accurate diagnostic rate based on pathological results was 90.2% for USCB, and 93.6% for OB. No significant difference was noted between USCB and OB groups in terms of diagnostic accuracy and the percentage of inadequate specimens. All cases in the USCB group had the sampling procedure completed within 10  minutes, but not in the OB group. No scars larger than 1  cm were found in USCB. Only patients in the OB groups had the need to receive general anesthesia and hospitalization and had scars postoperatively. Accordingly, USCB can serve as the first-line sampling tool for SC tumors with high diagnostic accuracy, minimal invasiveness, and low medical cost.