Vol 43 # 2 June 2011 - Kma.org.kw

June 2011
KUWAIT MEDICAL JOURNAL 149
readily demonstrate uptake in the case of suppression
of involved lobe in an autonomously functioning
nodule. Thyroid scan in a patient with hemiagenesis
is quite characteristic and a hockey stick sign may be
apparent. The increased functional burden caused by
the hemiagenetic gland would promote neoplasia.
However, the relevance of this is questionable since
all the patients with thyroid hemiagenesis whose TSH
levels were measured in Mariani’s series had normal
TSH value [2] . Even then it is impossible to avoid the
suggestion that long-standing elevated levels that can
lead to enlargement of the lobe might have played a
role in the development of thyroid carcinoma. Marshall
was among the first clinicians to describe numerous
anatomic variations of the thyroid, including the
clinical entity of hemiagenesis in 1895 [5] . Melnick and
Stemkowski described the hockey stick sign by imaging
study in patients with thyroid hemiagenesis [12] . They
also reported four patients and reviewed the world
literature on the subject of thyroid hemiagenesis which
revealed a total of 90 cases; however, only 17 out of
these were reported in the American literature [8] . None
of the four patients had thyroid cancer. Sheridan et al
reported a patient with hemiagenesis and Hashimoto’s
disease [13] . The authors identified and preserved the
parathyroid glands in normal position on the side of the
enlarged thyroid lobe. However, they did not identify
the parathyroid on the agenic side. The information
regarding the parathyroid on the agenic side is not well
documented in the literature. Piera et al reported three
cases of thyroid hemiagenesis in 1986 [14] ; however, they
documented the normal presence of parathyroid on the
side of the enlarged thyroid lobe only in one case. It is
important for the thyroid surgeon undertaking surgery
on a hemiagenic thyroid to appreciate the position of
the parathyroid and to make every effort to preserve
the parathyroid on the side of the thyroid lobectomy.
McHenry et al recently reported seven patients with
thyroid hemiagenesis - a collected experience of five
physicians [15] . They reported four female and three
male patients ranging in age from 17 to 58 years. The
pathologies included follicular adenoma, Graves’
disease, and nodular goiter. One patient had follicular
carcinoma of the thyroid. They emphasized the need
for preoperative recognition of thyroid hemiagenesis
in order to make critical decisions regarding surgical
intervention. McHenry et al suggested that all
patients with thyroid hemiagenesis who do not have
indications for surgery should have monitoring of their
thyrotrophic hormone levels, treatment of thyrotrophic
elevation with thyroid hormone, and careful follow-up
evaluation for the development of neoplastic disease [15] .
Our case is a unique one compared with cases reported
in the literature; the patient was an adult male with
absent right thyroid lobe (and not the left which is
more common) with severe hypothyroidism instead of
hyperthyroidism (which is more usual).
CONCLUSION
Recognition of this rare congenital anomaly is
important to avoid unnecessary contralateral neck
exploration with its potential morbidity and also to
make sure that patients receive careful follow-up and
appropriate therapy when necessary.
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