The
problem of goitre with particular consideration of goitre
resulting from iodine deficiency (I):
Classification, diagnostics and treatment
Andrzej Lewinski
Department
of Thyroidology, Institute of Endocrinology, Medical University
of Lódz; Poland.
Department of Endocrinology, Polish Mother's Memorial Hospital
– Research Institute, ódz, Poland.
Key
words:
goitre; iodine deficiency; classification; diagnostics;
treatment
June
7, 2002
Accepted: June 13, 2002
ABSTRACT
In
the present review paper, the following problems have been
brought up: 1) types of nontoxic goitre and applied classification,
2) physiological periods or states predisposing to non-toxic
goitre development, 3) evaluation of excessive stimulation
of the thyroid gland, 4) the treatment of iodine deficiency
consequences (non-toxic diffuse vs. non-toxic nodular goitre),
5) autoimmunologically-induced non-toxic goitre, and 6) positive
effects of iodine prophylaxis with respect to goitre prevalence.
The management of non-toxic nodular goitre, as well as of
thyroid nodules is a separate and very complex issue, and
– at the same time - the subject of our next review paper,
published in the same issue of NEL.
Types
of non-toxic goitre and
applied classification
The
most frequent effect of iodine deficiency is non-toxic goitre,
i.e., goitre unaccompanied by thyroid function disorders. Depending
on either the absence or the presence of nodules, diagnosed
during palpation, non-toxic goitre can be divided into diffuse
and nodular, respectively.
The classification of goitre, used in the 80s of the 20th century,
with regards to its size determined by palpation [1], is the
following:
Grade
0 – no goitre presence is found (the thyroid impalpable
and invisible);
Grade 1a – the thyroid gland, however palpable, remains
invisible, even in full extension of the neck (the thyroid not
enlarged);
Grade 1b – goitre – palpable in normal position and
visible in the upright position (full extension) of the neck;
nodular goitres are also classified into this size range, even
if they do not meet the criteria of enlarged thyroid gland;
Grade 2 – goitre – visible in normal position of the
neck; no palpation required to diagnose thyroid enlargement;
Grade 3 – very large goitre, clearly visible from distance.
The actually standing and simplified classification of goitre,
as proposed by the WHO [2], refers to the following criteria:
Grade
0 – no goitre presence is found (the thyroid impalpable
and invisible);
Grade 1 – neck thickening is present in result of enlarged
thyroid, palpable, however, not visible in normal position of
the neck; the thickened mass moves upwards during swallowing.
Grade 1 includes also nodular goitre if thyroid enlargement
remains invisible.
Grade 2 – neck swelling, visible when the neck is in normal
position, corresponding to enlarged thyroid – found in
palpation.
It should be emphasized that sonographic evaluation of the thyroid
size is more accurate in comparison with palpation, being especially
recommended in children with small goitre.
The diagnosis of nodular goitre results from palpable examination,
i.e., finding of uneven, nodular thyroid surface. The palpable
uneven areas correspond to, so-called, hyperplastic nodules,
usually present in enlarged thyroid gland. The hyperplastic
nodules in nodular goitre are characterized, among others, by
the lack of complete connective tissue encapsulation, no distinctive
morphological signs of pressure, exerted by the nodules on the
adjacent parenchyma of the thyroid gland, what differentiates
hyperplastic nodules from neoplastic ones. Thus, nodular goitre
is a benign, non-neoplastic lesion and – even if it has
been assigned to Class VII in Hedinger et al.'s classification
of thyroid tumours (1988) [3] – then, it has been defined
in its class as "tumour-like lesion", what corresponds
to its actual character. The palpably diagnosed nodular character
of thyroid enlargement places the goitre – regardless of
its actual size – in, at least, grade 1b in the classification
from 1986 [1].
The presence of foci with varied echogenicity, observed in sonographic
imaging, which, however, are not palpable, is not the basis
for the diagnosis of nodular goitre; it is impossible to reveal
occurrence of such foci only by palpation. The management of
the, so called, thyroid incidentalomas, will be discussed in
detail in our next review paper, published in the same issue
of NEL.
Nodular goitre may be either the subject of treatment with L-thyroxine
or of surgical intervention [4].
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