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.