Issue 4 - August 2010 - Pacini Editore

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agnosed as thyroid carcinoma of any type from 1979 to March
2004. A total of 1039 cases was found. Representative slides
from each case were selected and re-classified according to
the criteria recommended by standard texts 1 2 with the addition
of the categories suggested by the Chernobyl pathology
group 7 . Follow-up and clinical information were obtained
from the Reggio Emilia Cancer Registry and from the files of
the Pathology and Endocrinology Department. Follow-up was
available in 1009 cases and ranged from 4.5 to 29 years (median,
9.8 years; mean, 11.9 years) or until death. Among the
1009 cases, 159 patients had died; thyroid carcinoma was the
cause of death for 67 of the 159 patients, and these 67 cases
are the focus of the study.
Results. Among the 67 patients deceased as a consequence of
thyroid carcinoma, there were none of the tumors belonging to
any of the categories above mentioned, that is MIFCa, FV-PTC,
WDT-UMP, and FT-UMP. In fact, the vast majority of these
tumors shows a shows an exceedingly innocuous behaviour
following conservative surgery. The overdiagnosis of this condition
may lead to excessive treatment, including total thyroidectomy
followed by radioactive iodide therapy. This acquires a
particular importance with the encapsulated variant of FV-PTC,
which is associated with an excellent prognosis and for which
distant blood-borne metastasis has been rarely documented 8 .
The results of this study and a critical review of the pertinent
literature indicate that tumors with these features are associated
with an extremely favourable outcome and that they
do not play a significant role in the fatality rate of thyroid
carcinoma 9 10 .
references
1 DeLellis RA, Lloyd RV, Heitz PU, et al. Tumours of Endocrine Organs,
World Health Organization Classification of Tumours; Pathology
and Genetics. Lyon: IARC Press 2004.
2 Rosai J, Carcangiu ML, DeLellis RA. Tumors of the thyroid gland,
Atlas of Tumor Pathology, Third Series, Fascicle 5, Washington, D.C:
Armed Forces Institute of Pathology, AFIP 1992.
3 Franc B, De La Salmoniere P, Lange F, et al. Interobserver and intraobserver
reproducibility in the histopathology of follicular thyroid
carcinoma. Hum Pathol 2003;34:1092-100.
4 Van Heerden JA, Ray ID, Goellner JR, et al. Follicular thyroid carcinoma
with capsular invasion alone: a non-threatening malignancy.
Surgery 1992;112:1130-8.
5 Carcangiu ML, Zampi G, Pupi A, et al. Papillary carcinoma of the thyroid.
A clinicopathologic study of 241 cases treated at the University
of Florence, Italy. Cancer 1985;55:805-28.
6 Lloyd RV, Erickson LA, Casey MB, et al. Observer variation in the
diagnosis of follicular variant of papillary thyroid carcinoma. Am J
Surg Pathol 2004;28:1336-40.
7 Williams ED (on behalf of the Chernobyl Pathologists Group). Two
proposals regarding the terminology of thyroid tumors. Intern J Surg
Pathol 2000;8:181-4.
8 Chan JKC. Strict criteria should be applied in the diagnosis of encapsulated
follicular variant of papillary thyroid carcinoma. Am J Clin
Pathol 2002;117:16-18.
9 Piana S, Frasoldati A, Di Felice E et al. Encapsulated well-differentiated
follicular-patterned thyroid carcinomas do not play a significant
role in the fatality rates from thyroid carcinoma. Am J Surg Pathol
(E-pub ahead of print).
10 Rosai J. The encapsulated follicular variant of papillary thyroid carcinoma;
back to the drawing board. Endocr Pathol 2010;21:7-11.
5 th triennial congress of the italian society of anatomic Pathology and diagnostic cytoPathology
Vascular lesions of the thyroid
M. Papotti, M. Volante.
Department of Clinical and Biological Sciences, University of Turin
at San Luigi Hospital, Orbassano (Torino), Italy
Vascular lesions of the thyroid gland include benign endothelial
proliferations of reactive (Masson’s “hemangioma”),
benign neoplasms (cavernous hemangioma) and the rare
malignant angiosarcomas. These latter occur in pure form
or combined with anaplastic carcinoma (angio-sarcomatoid
carcinoma).
Reactive endothelial proliferations. In long standing nodular
goiter, regressive changes are common, including oedema,
fibrosis and calcification. Haemorrhage is an additional
event, which can be associated to complete nodule infarction,
followed by reparative processes such as granulation tissue
and reactive endothelial hyperplasia, closely resembling
intravascular papillary endothelial proliferations (Masson’s
phenomenon). In these cases, intraluminal papillary projections
in vascular spaces are lined by plump endothelial cells
with occasional atypias possibly leading to a suspicion of
malignancy. This condition may be an uncommon consequence
of fine needle aspiration biopsy or the result of spontaneous
intranodular haemorrhage/infarction. Completely
infarcted goiter nodules are a challenge for clinicians, radiologists
and pathologists: at ultrasound investigation, such
nodules having prominent vascular endothelial hyperplasia
are typically hyporeflecting and unhomogeneous and/or
calcified, all features simulating malignancy. At light microscopy,
the diagnosis of goiter may be missed (especially
in fine needle aspiration cytological material) in the absence
of residual micro- or macro-follicles due to haemorrhage and
endothelial hyperplasia.
WHAFFT. Another condition associated to vascular proliferation
in the thyroid gland was described under the acronym
WHAFFT, which stands for “Worrisome Histologic Alterations
Following Fine needle aspiration of the Thyroid”. The
alterations caused by the fine needle aspiration passages
included haemorrhage,, fibrosis, calcification and worrisome
lesions, like nuclear atypia, squamous metaplasia, capsular
pseudoinvasion, and plump endothelial hyperplasia in vascular
spaces, mimicking vascular tumors.
Thyroid hemangioma. It is very rare and generally results
from subsequent organization of intranodular hemorrhagic
events in goiter, thus suggesting their reactive rather than
neoplastic nature.
Angiosarcoma and Sarcomatoid carcinoma. Thyroid angiosarcoma
(or malignant hemangioendothelioma) was originally
described in mountain areas and associated to endemic
goiter. Grossly, a large extensively hemorrhagic mass is
recognized in the presence of multinodular goiter in the
surrounding parenchyma. Microscopically, elongated cells
either lining vascular spaces and protruding into them, or
arranged in small solid sheets are identified. Eosinophilic cytoplasm,
polygonal shape, large and hyperchromatic nucleus,
prominent nucleoli and numerous mitoses are typically present,
with occasional intracytoplasmic lumina. Tumor cells are
reactive for FVIII-related antigen, CD31, CD34 and vimentin,
as well as for cytokeratin (focally). The histogenesis of
thyroid angiosarcomas is controversial being the hypothesis
that all such tumors are indeed (angio)sarcomatoid anaplastic
carcinomas contrasted by the alternative evidence on the
existence of rare true angiosarcoma cases of the thyroid.
Whether reactive endothelial hyperplasia in long standing