SYNCHRONOUS MALIGNANT GLOMUS TUMOR WITH CLASSIC PAPILLARY THYROID CARCINOMA: A CASE REPORT.

Abstract

Introduction: glomus tumors are rare vascular neoplasms derived from these tissues and belong to a family characterized in their composition by glomus cells, blood vessels and smooth muscle in different proportions. Some cases have been considered malignant glomus tumors, comprising approximately 2.9% of all the lesions initially diagnosed as glomus tumors, and their most common location is the lower limbs.
Clinical case: A 51-year-old male patient, with unremarkable past medical history, was referred 17 days after a total thyroidectomy with lymph node dissection due to a thyroid nodule with Bethesda IV citology. The reported pathological diagnosis was at the level of the right lobe: classic papillary carcinoma. But an indeterminate area was also observed at the prevertebral level, interpreted primarily as undifferentiated thyroid carcinoma, with abundant angioinvasion.
Prior to the thyroidectomy, he presented a multislide neck tomography with contrast that reported spindle-shaped solid expansive process in the right lateral region of the neck and multiple nodular images in both lungs and liver compatible with secondarism. In addition, a magnetic resonance angiography with contrast had been performed where three juxtacortical supratentorial intraaxial solid images were observed.
Due to the large number of distant lesions, a biopsy was taken from a liver lesion; simultaneously the thyroid pathology was re-analyzed, due to the atypical behavior of a classic papillary thyroid carcinoma. After the review, it was concluded that the lesion in the prevertebral area and the liver corresponded to a malignant glomus tumor. It was not possible to define whether the thyroid location corresponded to the primary tumor or to another metastasis.
Conclusion: our patient was initially diagnosed as having a classic papillary thyroid carcinoma with an area of undifferentiation at the prevertebral level, but since its behavior with multiple liver, lung and brain metastases was not compatible with its usual presentation, it was decided to review the thyroid specimen in addition to obtaining biopsy liver lesions and studying them with immunohistochemical techniques, thus reaching a diagnosis of a malignant glomus tumor synchronous with its thyroid pathology. This type of neoplasm is extremely rare, and especially outside the extremities.