Kikuchi-Fujimoto Disease Masquerading as Metastatic Papillary Carcinoma of the Thyroid

1
Kikuchi-Fujimoto Disease Masquerading as
Metastatic Papillary Carcinoma of the
Thyroid Manuel Villa, MD1, Shailesh Garg, MD1,
Thomas Mathew, MD1, Louis-Joseph Auguste, FACS,
MD1 Northshore-Long Island Jewish Health System,
Manhasset, New York1
Discussion
Abstract
Case Presentation
Kikuchi-Fujimoto disease is a histiocytic
necrotizing lymphadenitis which is a rare and
benign condition that has been mainly described
in women younger than 40 years of age. It has
been described in men too and practically all
ethnic groups though more commonly in Asian
people. It can mimic other diseases such as
lymphoma, tuberculous adenitis, metastatic
disease, SLE, cat scratch disease and infectious
mononucleosis. The pathogenesis is unclear but is
believed to be an immune response of T cells and
histiocytes to an unknown inciting agent such as
EBV, HHV 6 8, HIV, toxoplasma and paromyxoma
viruses. Cellular destruction is hypothesized to
be due to apoptotic cell death mediated by CD8 T
lymphocytes. It usually presents with
fever, fatigue, weight loss, painful cervical
lymphadenopathy, arthritis and sometimes rash.
Lymphadenopathy is usually cervical but may
involve axillary, mediastinal, and iliac nodes.
Anemia, leukopenia, and elevated ESR can be seen
on laboratory studies. Lymph node biopsy needs to
be done to confirm the disease to exclude other
serious disorders like metastatic disease and
lymphoma. Pathology usually shows necrotic foci
on gross examination and paracortical foci with
histiocytic infiltrate on microscopic
examination. Although uncommon, a
recurrence rate of 3-7 has been reported. Signs
and symptoms usually resolve in 2 to 6 months and
there is no effective treatment though high dose
glucocorticoids with intravenous immunoglobulin
have been shown to be of some benefit. The
coexistence of Kikuchi disease and papillary
thyroid cancer in this patient presented a
complex and challenging clinical scenario
especially, the decision to perform a neck
dissection for clinically positive nodes despite
FNA showing reactive changes and the
intraoperative decision regarding how extensive
should the node dissection be. In summary,
although Kikuchis disease is a rare entity, we
should consider it in the differential diagnosis
when a young woman presents with fever and
cervical lymphadenopathy.
Kikuchi-Fujimoto disease also known as
histiocytic necrotizing lymphadenitis is a rare
cervical inflammatory lymphadenitis, most
commonly seen in young Asian women, although it
might be associated with autoimmune diseases and
commonly follows a self-limited course. We
present an unusual case of Kikuchi-Fujimoto
disease masquerading as metastatic papillary
carcinoma of the thyroid. A 30-year-old
young female presented 2 months post-partum with
complaints of neck pain and fever with CT scan
showing enlarged right-sided lymph nodes with a
thyroid nodule. A subsequent biopsy of the
thyroid nodule showed papillary thyroid carcinoma
and reactive inflammation of the lymph node. She
was electively taken for surgery when a total
thyroidectomy, central node dissection and a
right modified lymph node dissection was
performed for enlarged lymph nodes. After an
uneventful recovery, pathology came back as
papillary carcinoma of thyroid with one
metastatic lymphadenopathy and several other
lymph nodes with histiocytic necrotizing
lymphadenitis. This co-existence of
Kikuchi-Fujimoto disease with metastatic
papillary thyroid cancer at presentation is
unusual and presents a challenging and complex
management dilemma.
With no significant past medical history of SLE,
tuberculosis, lymphoma or autoimmune disorder,
her presumptive diagnosis was thyroid cancer with
possible metastasis with coexisting viral
infection. She underwent thyroid nodule FNA and
lymph node biopsy that showed papillary thyroid
cancer and reactive inflammatory changes in the
lymph node. Subsequently, she underwent a total
thyroidectomy with central node dissection and a
right radical modified lymph node dissection that
proceeded uneventfully. During her surgery she
had extensive lymphadenopathy that resulted in a
type III comprehensive neck dissection
encompassing submandibular gland and lymph nodes
level I to VI. Pathology showed papillary
carcinoma of thyroid with one positive lymph node
and remaining lymph nodes showing necrotizing
histiocytic lymphadenitis. Patient recovered well
from her surgery and underwent radioactive iodine
I-131 treatment postoperatively with post therapy
whole body I-131 scan demonstrating no iodine
avid tissue in the thyroid bed.
Intraoperative Image
Right Neck dissection
Introduction
Radiologic Findings
Initially described in 1972, Kikuchi-Fujimoto
disease is a rare and uncommon clinical condition
most commonly affecting young women in 3rd and
4th decades and presents typically as cervical
lymphadenitis with low-grade fever, malaise, and
fatigue although generalized disease has been
reported. The differential diagnosis is broad and
disease can mimic as lymphoma, tuberculosis,
metastatic disease, SLE, cat scratch disease and
infectious mononucleosis. Definitive diagnosis
is made by lymph node biopsy showing unique
patchy, irregular areas of eosinophilic necrosis
in the paracortex. The disease is self-limited
and symptoms resolve within 1-6 months with no
real effective treatment.

Transverse CT View of Neck showing right thyroid
nodule and right-sided lymphadenopathy
Neck Ultrasound showing 6 x 8 mm right thyroid
nodule
Coronal CT View of Neck showing right sided level
V lymphadenopathy
Sagittal CT View of Neck showing right thyroid
nodule 6 mm
References

• Clinical outcome and predictive factors of
  recurrence among patients with Kikuchi's disease.
  Int_J_Infect Dis. 2009 May 13(3)322-6. Epub
  2009 Feb 8.
• Kikuchi-Fujimoto Disease. Arch Pathol Lab Med-Vol
  132,
• Feb 2010
• 3. Kikuchis Disease A Rare Cause of Fever and
  Lymphadenopathy. Clinical Medicine Insights
  Pathology 20125
• 4. Kikuchi's disease (histiocytic necrotizing
  lymphadenitis). A clinicopathologic study of 79
  cases with an analysis of histologic subtypes,
  immunohistology, and DNA ploidy. Kuo TT. Am J
  Surg Pathol. 1995 Jul19(7)798-809.

Case Presentation
Pathologic Findings
Our patient is a 30-year-old female of Indian
origin with no significant past medical history
who initially presented to her PMD for neck pain,
swelling, fever and fatigue that was treated as
upper respiratory infection with antibiotics.
With no improvement in her symptoms and increased
neck swelling with palpable lymph nodes, an
ultrasound and CT scan was done showing extensive
right neck lymphadenopathy and an 8 x 6 mm right
thyroid nodule. Blood work showed elevated
monocytes and elevated TSH of 13.36 mIU/ml.

Histiocytic necrotizing lymphadenitis
Papillary Carcinoma of thyroid gland
Metastatic carcinoma of the lymph node