The Role of Ultrasound in a Diagnostically Challenging Case of Tuberculosis Cervical Lymphadenitis
Sandra Hopkins1,2, Clodagh Curran2, Therese Herlihy1, 1University College Dublin, School of Medicine, 2Our Lady of Lourdes Hospital Drogheda
Background:
Tuberculosis Cervical Lymphadenopathy (TCL) is the most common extrapulmonary presentation of tuberculosis. The treatment of TB is burdensome and prolonged so a definitive diagnosis or a very strong index of suspicion is needed to warrant commencement of treatment.
On initial presentation the patient had no history or clinical features other than an intermittent unifocal neck swelling to raise a suspicion of TCL. Initial imaging was inconclusive for cause of the swelling, antibiotic therapy was provided and the swelling subsided.
On second presentation the ultrasound identified features consistent with TCL and along with ultrasound guided biopsy aided diagnosis.
Ultrasound Findings:
B-mode and colour Doppler scanning were used to characterise the swelling. The initial US identified an avascular predominantly hypoechoic lesion with a couple of hyperechoic internal flecks. A pharyngeal pouch was considered a possibility but was ruled out on contrast enhanced CT(CECT). Retrospectively the appearances could be equated to Stage 3 TCL and the formation of a TCL cold abscess.
On 2nd presentation the ultrasound features were classic for 'Collar Stud' cold abscess (Stage 4 TCL) and contained bright flecks of hyalinosis within the caseous contents of the collection and an echogenic wall due to granulomatous inflammation, all highly indicative of TCL.
The TCL reached Stage 5 and sinused to the surface whilst the patient was awaiting US guided biopsy. The lesion retained the ‘Collar Stud ‘outline but appeared more homogenously hypoechoic at time of biopsy due to the prior discharge of the caseous contents through the sinus.
Conclusion:
The unifocal nature of this case of TCL and the timing of the initial presentation did not yield ultrasound findings highly specific for the TCL. However, the second ultrasound characterised the lesion as highly suspicious for TCL (Stage 4) and prompted the US guided biopsy for confirmation of the diagnosis.