INTRODUCTION-Encapsulated
Follicular variant of papillary carcinoma of the thyroid is a common thyroid
gland cancer with a highly indolent behavior, recently reclassification as a
non-malignant neoplasm has been proposed. There are two forms of follicular
variant- encapsulated or well circumscribed and infiltrative form [1].
Encapsulated follicular variant of papillary
carcinoma of thyroid characterized by an encapsulated (sometimes partial)
non-invasive tumor with a nearly exclusive follicular pattern, focal to diffuse
distribution of characteristic nuclear features of papillary carcinoma, a low
risk of lymph node metastasis, very low
recurrence risk and a strong association with RAS mutation [2-6].
MATERIAL
AND METHODS- A Patient was admitted in the indoor
department of surgery in LLRH where the patient was operated and the
thyroidectomy specimen sent for histopathological examination in the department
of Pathology, GSVM Medical College, Kanpur, India in the year of 2018.
The specimen was fixed in 10% buffered
formalin for 24-48 hrs after that tissue
was processed and stained by hematoxylin
and eosin staining and mounted with DPX.
Case REPORT- A 55 yr old female
presented to the OPD of our Surgery department of LLRH complaining of
left-sided neck swelling for past 4 yrs and hoarseness of voice and mild pain
in the neck.
At the time of initial presentation, the
mass had not been changing in size nor did the patient experience any
compressive symptoms. The patient denied any family history of thyroid disease.
On physical examination a 4 cm. swelling was palpable in the left side of front
of neck which moved with swallowing. Complete blood count and all biochemical
parameters of the patient were in normal limit. Ultrasound neck showed
isoechogenic to hypoechogenic circumscribed mass with smooth margins. No
calcification was seen.
Gross:
A thyroidectomy specimen was sent to the Pathology department of GSVM Medical
College for histopathological examination. Specimen received in one labeled jar
mentioned as thyroid gland tissue.
The specimen consists of one capsulated
greyish white to greyish brown soft to firm tissue piece altogether measuring
4x3x1.5 cm, outer surface was smooth and shiny. On cut section- one cyst was
identified measuring 2x1.5 cm cyst was filled with dark brown homogenous
material (Fig. 1).
.jpg)
Fig.
1 (A): Shows gross appearance of follicle variant of papillary carcinoma of
thyroid outer surface is smooth & shiny
B:
On cut section it is grayish white to grayish brown
Microscopic examination-
Section from thyroid
shows encapsulated well defined nodular tissue comprising of numerous
microfollicles. These microfollicles were lined by round to oval atypical cells
having large irregular nuclei, prominent nucleoli, fine powdery chromatin and
moderate amount of cytoplasm. Few cells was showing nuclear clearing and
growing adjacent to nodular areas few variable sized microfollicles and
marcofollicles filled with colloid material along with hemorrhage are also seen
(Fig. 2 to Fig. 5).
.jpg)
DiscussionS- Papillary thyroid
carcinoma has several well recognized histologic variants with follicular
variant a common type as defined by the WHO [7]. There are two main
types- encapsulated and infiltrative. The incidence of Follicular Variant of Papillary
carcinoma of thyroid has increased rapidly during the past decade, accounting
for ~24-33% of papillary thyroid
carcinoma, a more recent study indicated that the figure had risen to 41% [8].
With the excellent prognosis of follicular variant of papillary carcinoma
of thyroid, lobectomy should be the initial surgical procedure for tumors <2
cm or >2 cm without extra-thyroidal extensions, this kind of follicular
variant of papillary carcinoma of thyroid is regarded as low risk. Tumors >2
cm with extra-thyroidal extensions should undergo total thyroidectomy, which
could benefit the survival, tumors >4 cm was not the strong predictor for
total thyroidectomy [8]. Risk stratification of thyroid
carcinomas for both PTCs and follicular thyroid carcinomas is one of the most
important elements in the diagnosis of thyroid tumors, which aims to reduce
over diagnosis and overtreatment of thyroid carcinomas [9].
ConclusionS:
We are reporting the rare case of the encapsulated follicular variant of
papillary thyroid carcinoma because of its interest for surgeons and physicians
who are treating thyroid diseases. The encapsulated type of follicular variant
of papillary carcinoma of thyroid shows no invasion of surrounding thyroid
tissue, blood vessels or lymphatics and it was characterized by tumor
possessing both nuclear features of papillary thyroid carcinoma (e.g. nuclear
clearing, grooves and pseudo-inclusions and follicular growth pattern. On these
bases it can be differentiated from follicular adenoma and carcinoma.
Follicular variant of papillary
carcinoma of thyroid is best managed conservatively by lobectomy or thyroidectomy
alone without radio-ablative iodine or suppression therapy.
ACKNOWLEDGEMENTS
- All authors are thankful to the department of pathology GSVM
Medical College Kanpur, India for help in writing the paper.
CONTRIBUTION
OF AUTHORS
Research
concept- Dr. Swetlana Sachan
Research
design- Dr. Neelima Verma
Supervision-
Dr.
Anita Omhare
Materials- Dr. Vandana
Mishra
Data
collection- Dr. Swetlana Sachan
Data
analysis and interpretation- Dr. Anita Omhare
Literature
search- Dr. Anveksha Sachan
Writing article-
Dr. Swetlana
Sachan
Critical
review- Dr. Mahendra Singh
Article
editing- Dr. Swetlana Sachan
Final approval- Dr. Swetlana
Sachan
REFERENCES
1. Thompson
DP. Ninety-four cases of encapsulated follicular variant of papillary thyroid
carcinoma: A name change to Noninvasive Follicular Thyroid Neoplasm with
Papillary-like Nuclear Features would help prevent overtreatment. Mod. Pathol.,
2016; 29(7): 698-707.
2. Ghossein
R. Encapsulated malignant follicular cell derived thyroid tumors. Endocr.
Pathol., 2010; 21: 212-18.
3. Nikiforov
YE, Nikiforora MN. Molecular genetics and diagnosis of thyroid cancer. Nat. Rev.
Endocrinol., 2011; 7: 569-80.
4. Nikiforor
MN, Nikiforor YE. Molecular genetics of thyroid cancers: implications for
diagnosis, treatment and prognosis. Expert Rev. Mol. Diagn.,
2008; 8(1): 83-95.
5. Cancer
genome Atlas Research Network. Integrated genomic characterization of papillary
thyroid carcinoma. Cell, 2014; 159(3): 676–90.
6. Rivera
M, Ricarte-filho J, Knauf J, et al. Molecular genotyping of papillary thyroid carcinoma.
Follicular variant according to its histological subtypes (encapsulated vs.
infiltrative) reveals distinct BRAF and RAS mutation patterns. Mod. Pathol.,
2010; 23: 1191–1200.
7. DeLellis RA, Lloyd RV, Heitz PU, Eng C, et
al. Pathology and Genetics of Tumours of Endocrine Organs. WHO Classification
of Tumours, 3rd Edition, 2004; vol 8: pp. 320.
8. Tang J, Kong D, Bu L,
Gaosong Wu. Surgical
management for follicular variant of papillary thyroid carcinoma. Onco.
Target, 2017; 8(45): 79507-16. DOI: 10.18632/oncotarget.18525.
9. Kakudo
K, Satoh S, Inomata K, Kagiya T, Yamashita H, et al. Papillary thyroid
neoplasms in the 4th Edition WHO Classification of Tumors of
Endocrine Organs: Neoplasms with papillary thyroid carcinoma-type Nuclear
Features. J. Basic Clin. Med., 2018; 7(1): 21-35.