Gynecological malignancy mimicking a thyroid lymph node metastasis

SUMMARY: We present the case of a 69-year-old woman who attended the Endocrinology Unit of Modena for a suspicious lymph node in the left cervical compartment discovered during the follow-up of a recurrent gynecological malignancy. At neck ultrasonography, a thyroid goiter was detected, and the further cytological examination was inconclusive for thyroid nodule and compatible with a localization of an adenocarcinoma with papillary architecture for the lymph node. The histological examination after a left neck dissection confirmed the presence of an intracapsular metastasis of a papillary carcinoma immunohistochemically focally positive for thyroid transcription factor 1 and paired box 8 and negative for thyroglobulin. Subsequently, in the suspicion of a thyroid primitiveness, a total thyroidectomy was performed, revealing an intraparenchymal follicular variant of papillary thyroid carcinoma of 2 mm in the right lobe. During the follow-up, the appearance of a suspected cervical metastatic lesion led to another neck dissection, histologically compatible with a papillary carcinoma localization, immunohistochemically focally positive for thyroid transcription factor 1 and paired box 8, and negative for thyroglobulin. The histological revision of surgical specimens suggests the cervical recurrence of the prior gynecological cancer, rather than a thyroid carcinoma metastasis. The case described shows how carefully the cytological, histological and immunoistochemical results must be evaluated in oncological management, considering the whole patient’s history. LEARNING POINTS: Neck lymph node metastases occasionally originate from anatomically distant primary sites, such as breast, lung, gastro-intestinal tract, genito-urinary tract and CNS. Histological and immunohistochemical evaluations play an important role to identify the primary malignant site, although in some cases they could mislead the clinicians. A multidisciplinary approach and the evaluation of the whole medical history of the patient are mandatory to guide the diagnostic-therapeutic path and to avoid unnecessary treatments.