Anaplastic thyroid carcinoma (ATC) is a particularly fearsome form of thyroid cancer due to its extreme aggressiveness and dismal prognosis. Patients with ATC typically present with a rapidly enlarging neck mass with compressive symptoms. We report a case of ATC, mimicking a thyroid abscess; in a 52-year-old Chinese male with one month history of enlarging neck mass. Ultrasound of the neck was suggestive of a thyroid cyst and fine needle aspiration cytology was negative for malignancy. He presented again 2 weeks later with increased swelling and pain suggestive of right neck abscess. An incision and drainage was performed and histopathology result of a proximal isolated enlarged lymph node biopsied revealed metastatic carcinoma. Subsequent right thyroid wedge biopsy finding 1 month later were confirmatory of ATC.
Comparison of studies of cells derived from normal and pathological tissues of the same organ can be fraught with difficulties, particular with cancer where a number of different diseases are considered cancer within the same tissue. In the thyroid, there are 4 main types of cancer, three of which arise from follicular epithelial cells; papillary and follicular which are classified as differentiated, and anaplastic which is classified as undifferentiated. One assay that can be utilised for isolation of cancer stem cells is the side population (SP) assay. However, SP studies have been limited in part due to lack of optimal isolation strategies and in the case of anaplastic thyroid cancer (ATC) are further compounded by lack of access to ATC tumors. We have used thyroid cell lines to determine the optimal conditions to isolate viable SP cells. We then compared SP cells and NSP cells (bulk tumour cells without the SP) of a normal thyroid cell line N-thy ori-3-1 and an anaplastic thyroid cancer cell line SW1736 and showed that both SP cell populations displayed higher levels of stem cell characteristics than the NSP. When we compared SP cells of the N-thy ori-3-1 and the SW1736, the SW1736 SP had a higher colony forming potential, expressed higher levels of stem cell markers and CXCR4 and where more migratory and invasive, invasiveness increasing in response to CXCL12. This is the first report showing functional differences between ATC SP and normal thyroid SP and could lead to the identification of new therapeutic targets to treat ATC.
Cancer metastasis to the thyroid gland from non-thyroid sites is a rare presentation in clinical practice. The most frequent primary cancers that metastasise to the thyroid are renal cell carcinoma, followed by colorectal, lung and breast. We report a case of a 64-year-old Malay lady who presented with anterior neck swelling 4 years after an initial diagnosis of uterine leiomyosarcoma. She had undergone a hysterectomy procedure four years ago. Fine needle aspiration cytology of the thyroid mass suggested undifferentiated thyroid carcinoma. After multi-disciplinary discussion, the patient underwent thyroidectomy and the final histopathological diagnosis was metastatic leiomyosarcoma of the thyroid. The diagnosis was aided by an immunohistochemistry panel of positive myogenic markers, negative epithelial markers as well as the previous medical history of uterine leiomyosarcoma. Metastatic leiomyosarcoma of the thyroid may mimic primary undifferentiated (anaplastic) thyroid carcinoma (UTC) with a sarcomatoid pattern, medullary thyroid carcinoma (MTC) with spindle cells morphology and spindle cell tumour with thymus-like differentiation (SETTLE). Hence, a multidisciplinary approach must be practised by pathologists, surgeons and radiologists to consider metastatic lesions of the thyroid gland, especially when a previous history of cancer exists or is suspected.
A cross-sectional prospective study has been conducted on differentiated thyroid cancer (DTC) patients using negative (131)Iodine ((131)I) whole body scans and elevated thyroglobulin (Tg) levels. The main objective of this research was to determine the prevalence of the conversion of differentiated to dedifferentiated thyroid cancer patients during follow up at the Hospital Kuala Lumpur. It has been demonstrated that fluorodeoxyglucose (FDG) uptake is inversely proportional to the iodine concentration and to differentiation of the cells.