FIGURE 1- 20-year female with swelling behind the angle of mandible
On examination, she was cooperative, alert and well oriented to time,
place, and person. She had a BMI of 20.5 kg/M2. Her
vital signs were stable. There was no significant finding on her general
examination besides cervical lymphadenopathy. Her cervical groups of
lymph nodes were enlarged bilaterally with a maximum being 2x2cm. On
further examination, the lymph nodes were discrete and non-tender with
intact overlying skin and without signs of inflammation, ulceration, and
discharge. Oral, otolaryngologic, and systemic examinations were
unremarkable.
Her baseline investigations were sent. Her haematological parameters
were within normal limits. The thyroid function test was normal. Chest
X-ray findings were normal. Serological tests were non-reactive. She was
then advised for USG of Neck.
The USG of the neck showed right parotid gland enlargement with multiple
round-shaped hypoechoic lesions involving the right parotid and
submandibular regions, likely necrotic lymph nodes, one measuring 13*11
mm. For further evaluation, she was advised for FNAC (Fine Needle
Aspiration Cytology) along with a biopsy of the affected lymph node.
Smear was prepared which showed moderate cellular specimen containing
few granulomas composed of epithelioid cells in the background of
polymorphous lymphoid cells. Ziehl-Neelsen stain done for acid-fast
bacilli was negative. FNAC showed features suggestive of chronic
granulomatous lymphadenitis while a biopsy of the right cervical lymph
node carried out revealed widespread necrosis along with disruption of
the normal lymph node architecture. The normal follicular arrangement of
lymphocytes was lost and focal areas of haemorrhage were also noted.
Granulomas or giant cells were absent.
FNAC along with biopsy reports were suggestive of necrotizing
lymphadenitis. Based on the histopathological findings diagnosis of
Kikuchi Fujimoto disease was made.
The patient was admitted after initial evaluation in OPD. She was then
managed conservatively with analgesics, antipyretics, and antibiotics
for three days. On the 4th day of admission, she was
sent home. She along with her family members were reassured that KFD is
a self-limiting condition and advised to come for a follow-up in 2
months.
On follow-up 2 months later, her neck swelling and fever were found to
have subsided. The patient and patient parties were satisfied with the
treatment provided.
3 DISCUSSION
Kikuchi disease, since its first description in1972, has puzzled many
clinicians because of its rarity and vague clinical presentation and is
therefore frequently underdiagnosed. This disease is known to have a
higher prevalence in young females of Asian and East European origin,
the usual age of presentation being the third to fourth decades of
life.2 The female: male ratio was classically
overemphasized to be 4:1 but after the discovery of more and more cases
worldwide, the actual ratio is believed to be closer to 1:1. 7 The
precise incidence and prevalence of this condition in the general
population have not been estimated yet. 8
Its etiopathogenesis is not entirely understood and remains
controversial. A long list of viral triggers, more commonly associated
with Epstein Barr Virus but without a direct causal relation, points
toward the infectious cause and its association with other autoimmune
diseases gives an insight into its possible autoimmune nature. With this
limited knowledge, the cause can be explained as an unknown (viral or
infectious) trigger leading to an inflammatory process in a susceptible
population. 9
A comprehensive review by Bosch et al. shows unilateral cervical
lymphadenopathy involving lymph nodes of the posterior triangle to be
the most common clinical manifestation, which was present in 56% to
98% of the patients. Lymphadenomegaly would range from 0.5 to 4 cm,
rarely greater than 6 cm, and 30% to 50% of patients had a low-grade
fever with upper respiratory symptoms. 2 Our patient
also had a low-grade fever with right cervical lymphadenomegaly of 1.3
cm, which is consistent with the review article. The skin might be
involved in 40% of the cases, with the presentation varying from
nonspecific skin rash to lupus-like findings. Other less frequent
manifestations can be nausea, vomiting, weight loss, night sweats,
fatigue and arthralgia, which would otherwise mimic B-like
presentation.4
Diagnostic challenge poses a major problem when approaching patients
with this condition, which subjects patients to get inappropriate
treatment for alternative etiologies. This happens because of the lack
of its pathognomonic signs and symptoms and other common conditions that
fit better in the clinical picture like tuberculosis, viral infections,
systemic lupus erythematosus and metastatic
disease.10Excisional lymph node biopsy is required for
its definitive diagnosis, which can be supplemented with necessary
laboratory and radiological investigations. 2 The
histopathological examination reveals well-circumscribed areas of
coagulative necrosis with karyorrhectic nuclear debris, a large
accumulation of histiocytes in the periphery and relative paucity of
neutrophils and eosinophils. 11 The peculiar feature
of these histiocytes is the crescent-shaped nuclei and phagocytosed
debris, which differentiates this condition from tubercular
lymphadenitis and lymphoma. 12Moreover,
Immunohistochemistry (IHC) shows histiocytes positive for
myeloperoxidase and CD68, T cells positive for CD8 and infrequent B
cells, which rules out lymphoma from the list. Biopsy in KFD fails to
show hematoxylin bodies along with areas of vasculitis around areas of
necrosis, which are specific to SLE. 11 Fine Needle
Aspiration Cytology (FNAC) can also be used for its diagnosis but its
use is limited by the fact that specimen collected from this procedure
is operator sensitive and it requires careful precautions to preserve
the architecture of the lymph nodes. 13 Ultrasound can
be used as an imaging modality in limited-resource settings to support
the diagnosis, which can show hypervascularity and lymph node
enlargement. 14 In our case, USG findings initially
pointed towards tubercular lymphadenitis which was later corrected by
FNAC and excisional biopsy.
Through this case, we highlight that Kikuchi disease due to a wide range
of clinical presentations can be challenging to diagnose. Dorfman and
Berry as part of the Lymphoma Task Force have reported a misdiagnosis
rate of 40% for Kikuchi Disease. 15 Most of them are
misdiagnosed as malignancy while in our part of the world tuberculous
lesion is another frequent misdiagnosis. This misdiagnosis leads to the
concern of expensive management procedures for a mild self-limiting
illness. This adds a burden on limited health care resources as well as
the patients physically, mentally and financially. We want to increase
awareness about KDF among clinicians and encourage them to consider it
as an important alternate diagnosis in patients with lymphadenopathy of
unclear aetiology.
Since the condition has a benign and
self-limiting course, observation alone is the commonly used approach in
its management. The lack of specific treatment for this condition
reiterates the poor understanding of its etiopathogenesis. Antipyretics
and analgesics can be used for supportive management and in case of
severe disease, prolonged corticosteroid use may be necessary, once the
infectious cause has been ruled out. 4 The patient in
our case had mild symptoms, which subsided with the symptomatic
treatment for pain and fever.