Cervical lymph node metastasis from thyroid papillary microcarcinoma: a case report.

Abstract

Abstract: 

Thyroid papillary microcarcinoma is defined as that which measures 10 mm. or less in its widest diameter. This lesion is considered to have an excellent prognosis, generally following a benign course. However, they may occasionally exhibit aggresive behaviour in the form of lymphatic metastasis based on a number of predictive factors, namely bilaterality, age below 50 years, size over 5.75 mm., extrathyroidal extension and lymphovascular invasion. The ideal diagnostic approach includes, among others, clinical suspicion, ultrasound, fine needle aspiration and eventual surgery to confirm the diagnosis. 

The objective is to report the case of a thyroid papillary microcarcinoma diagnosed after having metastasized to cervical lymph nodes and the serial sectioning with thorough examination of the thyroidectomy specimen, following diagnostic procedures that evidenced no abnormalities, thus hindering the early study and suspicion of a primary origin in the thyroid gland, prompting instead the presumptive diagnosis of other entities such as hematolymphoid neoplasms, for which the use of fine needle aspiration as the initial method of diagnosis is controversial.

A 53 year old male patient presented with right laterocervical lymphadenopathies. A toracoabdominal computerized tomography (CT) scan was performed, along with a laringoscopy and thyroid ultrasound, all of which revealed no unusual findings. The laterocervical lymph node conglomerate was then surgically resected, its intraoperative examination resulting in the diagnosis of carcinoma with histological features suggestive of a primary origin in the thyroid gland, and TTF-1 staining was positive. After the thyroidectomy and subsequent serial sectioning and examination of the specimen in its entirety only 2 foci of papillary microcarcinoma were identified, one in each lobe and both below 2 mm. in size.

In conclusion, it is therefore markedly important to consider a primary origin in the thyroid gland when faced with lymphadenopathies suspicious for malignancy, even when the imaging and clinical findings are inconclusive, whether due to being operator dependent or having low sensitivity when it comes to microcarcinomas.