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