Tall cell papillary thyroid carcinoma metastatic to femur: evidence for thyroid hormone synthesis within the femur

Anaplastic Spindle Cell Squamous Carcinoma Arising from Tall Cell Variant Papillary Carcinoma of the Thyroid Gland: A Case Report and Review of the Literature

Tall cell variant (TCV) of papillary thyroid carcinoma (PTC), an aggressive form of thyroid cancer, is characterised by 50% of cells with height that is three times greater than the width. Very rarely, some of these cancers can progress to spindle cell squamous carcinoma (SCSC) resulting in cancers with elements of both SCSC and TCV PTC. Here we report a case of SCSC arising from TCV PTC. In addition to this case, we have performed a literature review and compiled all published reports of SCSC arising from TCV PTC, including the nature of treatment and the prognosis for each of the 20 patients recorded. This is intended for use as a guide for clinicians in what the most appropriate treatment options may be for a newly diagnosed patient. Due to the rarity coupled with diagnosis occurring at a very advanced stage of disease progression, performing clinical trials is difficult and therefore drawing conclusions on optimal treatment methods remains a challenge.

Tall cell variant of papillary thyroid carcinoma: sonographic and clinical findings

We retrospectively reviewed the clinical and sonographic features of 8 patients with 10 tall cell variants of papillary thyroid carcinoma. The mean age of the patients was 57 years (range, 34-72 years). The tumor sizes varied. Of the 8 patients, 5 had symptomatic masses, and 3 had incidentalomas. Three patients had recurrences and 1 died of pulmonary metastasis within a mean time of 30 months. The tall cell variants often appeared as microlobulated markedly hypoechoic nodules with microcalcifications and extrathyroidal extension on sonography and were always associated with lymph node metastasis. The tall cell variant of papillary thyroid carcinoma should be included in the differential diagnosis of an aggressive thyroid tumor with symptoms and cervical nodal metastasis.

[A case of hyperthyroidism due to functioning metastasis of differentiated thyroid carcinoma. Discussion and literature review]

We report on a very rare case of hyperthyroidism due to multiple autonomously functioning bone metastasis of papillary thyroid cancer in a 79-year-old woman. This situation remains extremely uncommon, as shown by our review of the literature; only 47 similar cases have been published from 1946 to 2005. The pathogenic mechanism remains largely unknown in spite of several hypotheses (conjunction in volume and differentiation, auto-antibodies). Hyperthyroidism can be severe, and often T3 levels are markedly more elevated than T4 levels. Apart from hyperthyroidism caused by the hormone-production, clinical features are similar to that of usual metastatic thyroid cancer, occurring in elderly women in most cases, and of follicular type on pathology. Metastases mostly occur in bones and lungs. Treatment relies mainly on radio-iodine ((131)I), which is efficient on hormonal disorders, and prognosis appears to be correlated with the ability of the metastatic sites to concentrate radio-iodine.