ABSTRACT
Synovial Sarcoma (SS) is the fourth most common soft tissue sarcoma, characterized by translocation t(X;18) (p11.2;q11.2). Although its histological features have been extensively described, this entity is characterized by a wide morphological spectrum so that the recognition can be very challenging at atypical anatomical localization, like the thyroid. We describe a case of a 42-ys-old female patient complaining a cervical swelling due to left intrathyroid nodule, measuring 35 mm in its greatest dimension. A Fine Needle Aspiration Cytology (FNAC) was performed and diagnosis of indeterminate neoplastic lesion, indefinite whether primary or metastatic, was formulated. After complete thyroidectomy, the histological picture of the nodule was characterized by a dual cellular population: several glandular structures composed by columnar cells with clear cytoplasm were embedded in a highly cellular stroma composed of spindle-shaped elements. Immunohistochemistry and molecular biology confirmed the morphological suspicion of SS identifying the fusion transcript SYT-SSX1 and thus ruling out several differential diagnoses which include more common thyroid malignancies. Moreover a synchronous papillary microcarcinoma was detected in the controlateral lobe.This case is noteworthy since it describes the synchronous presence in the thyroid of two completely different malignancies, the first one belonging to the soft tissue neoplasm category and the other one originating from the thyroid follicular epithelium.
Subject(s)
Neoplasms, Multiple Primary/pathology , Sarcoma, Synovial/pathology , Thyroid Cancer, Papillary/pathology , Thyroid Neoplasms/pathology , Thyroid Nodule/pathology , Adult , Biomarkers, Tumor/analysis , Biomarkers, Tumor/genetics , Biopsy, Fine-Needle , Diagnosis, Differential , Female , Gene Rearrangement , Humans , In Situ Hybridization, Fluorescence , Neoplasms, Multiple Primary/chemistry , Neoplasms, Multiple Primary/genetics , Neoplasms, Multiple Primary/surgery , Oncogene Proteins, Fusion/genetics , Predictive Value of Tests , Sarcoma, Synovial/chemistry , Sarcoma, Synovial/genetics , Sarcoma, Synovial/surgery , Thyroid Cancer, Papillary/chemistry , Thyroid Cancer, Papillary/genetics , Thyroid Cancer, Papillary/surgery , Thyroid Neoplasms/chemistry , Thyroid Neoplasms/genetics , Thyroid Neoplasms/surgery , Thyroid Nodule/chemistry , Thyroid Nodule/genetics , Thyroid Nodule/surgery , Thyroidectomy , Tumor BurdenABSTRACT
Thyroid gland is one of the most vascularized organs of the body, nevertheless clinical and surgical series report an incidence of secondary malignancies in this gland of only 3%. Colorectal carcinoma metastatic to the thyroid gland is not as uncommon as previously believed, infact the number of cases seems to be increased in recent years due to the more frequent use of fine-needle aspiration cytology (FNAC) guided by ultrasonography. Although kidney, breast and lung metastases to the thyroid are frequent, metastasis from colon cancer is clinically rare with 52 cases reported in the literature in the last 5 decades and three cases described as solitary thyroid metastasis from the colon cancer without any other visceral metastases. To the best of our knowledge, we report the fourth case of solitary, asymptomatic thyroid metastasis from colon cancer without involvement of other organs. We discuss the importance of FNAC to detect metastatazing process as a compulsory step of the diagnostic and therapeutic management algorithm, combined with a molecular biology approach. A review of the last 5 decades literature, to update the number of cases described to date, is also included.
