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papillary carcinoma is the most common type of thyroidal malignancy ( 1 ) . within variable morphologic variants of papillary thyroid carcinoma ( ptc ) ,
follicular variant of ptc comprises 15%-20% of ptc , which is the second most common variant following the conventional ptc ( 2 ) . among the various subtypes of follicular variant ptc ,
diffuse follicular variant papillary thyroid carcinoma ( dfvptc ) is very rarely found . as it is a variant of ptc , diagnostic nuclear features as nuclear clearing , grooves , and seldom nuclear pseudoinclusions are evident .
typically , it arises in young females and often has a poorer clinical course than other subtypes of follicular variant ptc .
the tumor shows no encapsulation , diffuse permeating micro- and macrofollicular tumor cells devoid of papillary architecture .
while usual follicular variant ptc has an excellent prognosis , dfvptc is considered to have poor prognosis , based on the multicentricity of tumor , extensive extrathyroidal extension , vascular invasion and nodal metastasis , etc .
we describe a case of dfvptc arising in a 69-yr - old male rather than young female .
a 69-yr - old man was referred to our institution for the management of his neck mass .
he has visited the previous hospital on february 17 , 2011 with hoarseness for a few months .
he was medicated for hypertension , and no other past history was found . the physical examination on him revealed firm ,
fixed mass on left anterior neck and limited motility of the vocal cord was observed . by further evaluation with computed tomography scan , a huge
, ill - marginated mass was found , invading the left thyroid lobe and isthmus ( fig .
fine - needle aspiration was done to the mass in the left thyroid and left neck nodes , diagnosed as papillary thyroid carcinoma with lymph node metastases . in our institution , the aspiration cytology slides of thyroid and lymph nodes were reviewed , and also the diagnosis of papillary thyroid carcinoma with lymph node metastases was rendered .
after referred to our institution , he received bilateral total thyroidectomy with central compartment neck node dissection .
after 17 days from the operation , the patient expired due to asphyxia caused by an unexplained bleeding in the gastrointestinal tract . on examination of resected specimen , pathologic diagnosis of diffuse follicular variant papillary thyroid carcinoma ( dfvptc ) was rendered .
multiple carcinomas were found in both thyroids , infiltrating into the esophagus , trachea , sternum , and mandible with multiple metastases in the regional lymph nodes .
the specimen was consisted of entire thyroid ( total weight : 29.8 g , right lobe : 3.5  3.8  1 cm , left : 6  4  2.3 cm ) with regional lymph nodes , and multiple biopsies from tracheal , esophageal , sternum , mandibular area .
sectioned surface showed poorly marginated yellowish and fibrotic tumor ( 3.7 cm ) , which was infiltrative and totally replacing the entire lobe ( fig .
right lobe seemed to be grossly normal , but a 0.9 cm - sized vague nodule was found in lower pole on sectioning .
hematoxylin - eosin ( he ) stain revealed diffuse , vaguely nodular tumor in left thyroid ( fig .
the tumor showed micro- and macrofollicular growth pattern , which was infiltrating into the thyroid parenchyma , extrathyroidal skeletal muscle and fibroadipose tissue .
cytologically , each of tumor cells revealed vesicular nuclei with nuclear clearing and grooves , which are histologic findings of papillary thyroid carcinoma ( ptc ) ( fig .
the other histologic features , such as intranuclear pseudoinclusion , psammomatous calcification , or discrete papillary structure were rarely seen .
six of 60 lymph nodes metastases were found from neck dissection , of which the largest size was 2.2 cm .
metastatic carcinoma in lymph nodes showed same histologic features as in the thyroid , like micro - and macrofollicular growth pattern of tumor cells harboring nuclear features of ptc ( fig .
permeating tumor cells were found in separately sent esophagus and tracheal cartilage , which also exhibited the same histologic features as in the thyroid ( fig .
3a - c ) . for ancillary interest , several immunohistochemical stainings - galectin-3 , cytokeratin ( ck ) 19 , cd56 , thyroglobulin , ki67 ,
diffuse positive for galectin-3 , ck19 , and negative for cd56 were seen in tumor area , which was vice versa in normal thyroid tissue ( fig .
ki67 labeled tumor cells were about 5% ( found up to 37/high power field ) and p53 nuclear expression was about 10% of tumor cells .
follicular variant is common variant of papillary thyroid carcinoma , comprising 15%-20% of papillary carcinomas .
several subtypes of follicular variant of papillary thyroid carcinoma exist , such as encapsulated follicular , diffuse follicular , and macrofollicular variants ( 2 ) . encapsulated follicular and macrofollicular variants have an indolent course , and usually encapsulated .
diffuse follicular variant papillary thyroid carcinoma is first described by sobrinho - simes et al .
histologically it typically lacks of encapsulation , reveals predominant microfollicular architecture , and vascular invasion and metastases to lymph nodes and distant area are common . in 1995
, mizukami et al . ( 4 ) reported one case of dfvptc in 13-yr - old boy .
ivanova et al . ( 5 ) analysed clinicopathologic and immunohistochemical characteristics of 10 cases of dfvptc in 2002 .
they compared dfvptc with common fvptc and common ptc , showed several distinguised properties of dfvptc from others in clinical behaviour and histological features .
the significant findings of dfvptc were : female predominancy ( male to female ratio was 1:9 ) ; young female ( mean age of 26.8 yr ) ; multicentricity ; extrathyroidal extension ; lymph node metastasis ; venous invasion
. other morphologic feature of dfvptc included no necrosis , no fibrosis , no lymphocytic infiltration , and rare psammoma bodies with low mitotic index ( mean 1.3% ) .
the patient presented with refractory hoarseness and underwent bilateral total thyroidectomy with central compartment neck node dissection .
extensive tumor cell infiltration into left thyroid and surrounding structures , nodal metastases were found on pathologic examination .
he was diagnosed as dfvptc and expired on the 17 post operative day due to unexplained bleeding of surgical site .
the nuclei of tumor cells demonstrated features of conventional ptc , such as nuclear clearing , grooves , and seldom pseudoinclusions .
the tumor involved entire left lobe and part of right lobe , extended to the adjacent structure , including tracheal cartilage , esophagus , sternum , mandible , extrathyroidal skeletal muscle and fibroadipose tissue .
on immunohistochemical staining , the tumor was positive for galectin-3 , ck19 , and lacked the cd56 expression compared to the juxtaposed normal thyroid tissue , which is consistent with conventional ptc .
some of tumor cells were labeled with ki67 staining ( about 5% , figure not shown ) and expressed p53 ( about 10% , figure not shown ) .
based on differentiated follicular architecture , cytologic and immunohistochemical features of ptc and biologic aggressiveness , present case is compatible with dfvptc .
( 5 ) , which showed the tendency of young female predominancy of occurence , present case is distinguished from the previously reported cases of dfvptc in old age and male gender .
diffuse follicular variant papillary thyroid carcinoma ( dfvptc ) is a rare variant papillary thyroid carcinoma . 
 dfvptc typically occurs in young females , extensively involves one lobe or both lobes entirely with frequent nodal metastasis and vascular invasion . 
 in contrast to the other subtypes of follicular variant , dfvptc has biologically aggressive behavior . 
 we present a case of dfvptc arising in a 69-yr - old male patient . 
 he presented hoarseness for a few months . 
 following diagnosis of malignancy on aspiration cytology , total thyroidectomy with neck dissection was performed . 
 the tumor involved both lobes of thyroid , encroaching the surrounding structures including tracheal cartilage and esophagus . 
 multiple lymph node metastasis and vascular invasion were also found . 
 the patient passed away due to the unexplained bleeding of surgical site .