Durr-e-Sabih  ( Atomic Energy Medical Centre, Nishtar Hospital, Multan. )
Sher M. Khan  ( Atomic Energy Medical Centre, Nishtar Hospital, Multan. )

A nodule in the front of neck is usually thyroidal in origin, followed by a lymph node mass. A ‘cold’ thyroid nodule, i.e., one which does not concentrate radio-iodine or technetium on scintiscanning is usually subjected to a fine needle aspiration, to drain cysts or to obtain cytological samples. We present a case where such an approach would have been potentially catastrophic.

A 32 year old housewife presented with six month’s history of fever, loss of vision in the right eye, slight weakness of the left arm and a three month’s history of a nodular swelling in the front of neck. The nodulewas located to the right of midline, above the sternoclavicular joint, and was firm and fixed. The possibility of a thyroid nodule or a lymph node mass was suggested by the referring physician and she was sent to this Centre for a thyroid scan. A Tc00m scan shOwed a cold area in the right lobe of the thyroid (Figure 1).

Ultrasonography was done as is the routine with all our patients who have solitary ‘cold’ nodules on scintiscanning, Realtime pictures showed a cystic lesion with prominent pulsations in the centre and communication with the common carotid artery (Figure 2).

The picture was unmis­takable for an aneurysm of the common carotid artery. On re-examining the patient the mass was found to be expansile and there was an audible bruit on the right side of the neck.

A \'cold\' thyroid nodule is usually subjected to a biopsy procedure, open or more often fine needle aspiration. While some advocate sono­graphy prior to biopsy¹, others have not found it to be very helpful². In this case, the carotid artery aneurysm was distbrting the thyroid contour and appeared to be a ‘cold’ thyroid nodule on scinti­scanning. An attempt at fine needle aspiration could have been disastrous because of the brittle walls. Althobgh an extremely rare occurrence, it does underscore the complementary nature of ultrasonography to nuclear medicine procedures. The clinical signs were quite convincing, but at times even the most obvious clinical signs can be missed in a busy outpatient department or a private clinic. It is the duty of the diagnostician to devise routines in his laboratory to extract the maximum possible information from any given clinical situation. At the same time such proce­dures should be cost effective, rapid and accep­table to the patient. Ultrasonography is an elegant example of such a complementary modality in a background of nuclear medicine.

1. Walker, J., Findlay, D., Amar, 5.5., Small, P.G.,  Wastie, M.L. and Pegg, C.AS. A prospective study of thyroid Ultrasound scan in the clinically solitary thyroid nodule. Br. J. Radiol., 1985; 58 617.
2. Wernier, S.C. and Ing bar, S.H. The thyroid; a fundamental and clinical text. New York, Harper and Row, 1978, p.515.