CLINICAL UPDATE
Case Report: Atypical thyroid nodule
FNA( fine needle aspiration) of a woman’ s thyroid nodule is reported as“ atypical” with the
A pathologist’ s conclusion“ raising the possibility of follicular neoplasm”. At this point she is referred to me. Ms RH, aged 50, had a solitary and symptomatic( compression) left sided thyroid nodule of 4cm maximum dimension. This occurred against a background of longstanding hypothyroidism and thyroxine replacement for over a decade. by Dr Simon Ryan, Endocrine Surgeon,
Hollywood Medical Centre. Tel 9386 3070
I explain to the patient that nodules with this type of FNA finding usually require a histological – rather than cytological – specimen. Atypical follicular-type aspirates can arise from benign nodules such as hyperplastic nodules and follicular adenomas but also from follicular thyroid carcinomas.
These entities are presently best distinguished by a histological specimen( i. e. operative), which allows close inspection of the nodule capsule to determine whether there has been a breach of this capsule by tumour cells. A breach defines malignancy in follicular thyroid lesions. A nodule with capsular disruption( follicular carcinoma) can often require further surgical and adjuvant treatment, while benign lesions usually require no further treatment.
Many patients come to thyroid surgeons in this situation fearful they have a confirmed cancer, however only about 20 % of nodules with atypical follicular aspirates are follicular carcinomas.
� Ultrasound of a large left-sided thyroid nodule( in a different patient).
I offered this patient a total thyroidectomy given that she was already hypothyroid and taking thyroxine and in this way would avoid a completion thyroidectomy in the event of a follicular thyroid carcinoma being diagnosed on a hemi thyroidectomy specimen.
After surgery, the nodule was confirmed to be benign histologically – a hyperplastic( colloid) nodule. However, within this specimen was a second lesion, a 2.3 mm papillary thyroid carcinoma( PTC).
While another source of alarm for patients, PTCs less than 10mm – so-called microcarcinomas – are found in up to 30 % of thyroidectomy specimens in autopsy studies. They nearly uniformly have benign behaviour and do not warrant further treatment, even if found within a hemithyroidectomy specimen.
Ms RH is now well, on a stable dose of thyroxine, with normal parathyroid function and unremarkable voice.
The learning points from my perspective are:
�� ���������������������������������� suggestive of follicular neoplasm usually lead to a surgical biopsy for capsular assessment, however the majority of these nodules are benign.
�� ������������������������������������� in thyroidectomy specimens where the original operation was for benign indications such as multinodular goitre and Graves ' disease; this patient should be reassured regarding the minimal clinical significance of these lesions and lasting treatment via thyroidectomy.
Referring Doctor’ s Perspective
This woman drew my attention to her neck, having noticed a swelling over the left thyroid gland that had been bothersome for about two weeks, that is, a mild globus sensation while swallowing and pressure in her neck.
She had a palpably enlarged non-tender left thyroid nodule and no palpable regional lymph nodes. I referred her to a Perth radiologist for thyroid ultrasound and, if indicated, guided FNA of the nodule. This was done.
Histology of the aspirate was atypical and raised the possibility of follicular neoplasm for which she was referred immediately to the thyroid surgeon.
For me, as a GP who has not thought long and hard about it, I do not have unanswered questions after reading the broad explanation in Dr Ryan ' s letter. I believe specialist correspondence should enrich our knowledge of the relevant subject.
This experience will not change the way I
Dr Sam Irekpolo, Jurien Bay
General Practice. Tel 96521484
manage similar thyroid patients in future but it will improve my patient counselling prior to referral. I can see that teaching FNA( fine needle aspiration) to GPs would be useful in some cases where distance might be a constraint.
Declaration: This Case Report is supported by an independent educational grant to Medical Forum from Hollywood Private Hospital. medicalforum 39