Effectiveness and safety of lenvatinib in a series of advanced well-differentiated thyroid carcinomas from a single tertiary cancer center and literature review.

BACKGROUND: Treatment of advanced differentiated thyroid carcinoma (DTC) remains a challenge as 25-50% of patients with locally invasive or distant metastatic disease become refractory to radioiodine (RAI) therapy. Tyrosine kinase inhibitors (TKI) are increasingly used in this setting. The SELECT trial demonstrated that lenvatinib, a multikinase inhibitor, significantly improved progression free survival (PFS) compared to placebo. Our aim was to report the effectiveness and safety of lenvatinib in our series of patients with advanced DTC. METHODS: A total of 25 patients with advanced DTC followed at a single tertiary center from January of 2016 to January of 2022 were retrospectively reviewed. RESULTS: Patients were treated with a mean daily dose of lenvatinib of 16.9 mg for a mean of 9.1 months. Median estimated PFS was 31.3 months. One patient achieved complete response. The objective response rate (ORR) was 40% and the disease control rate was 84%. The mean change in summed longest diameter of target lesions from baseline to nadir was -36.9%. Lenvatinib prolonged the tumor volume doubling time in 86.7% patients. Interestingly, we found that patients treated with a lower dose of lenvatinib (<16.9 mg daily) had a significantly higher PFS and ORR than patients treated with higher dosages (>16.9 mg). Adverse events were frequently reported. CONCLUSIONS: Our results confirm the effectiveness of lenvatinib in the management of patients with advanced DTC and support the need to adjust the dosage of lenvatinib to patient´s performance status and comorbidities.

Homozygous Calcium-Sensing Receptor Polymorphism R544Q Presents as Hypocalcemic Hypoparathyroidism.

Context: Autosomal dominant hypocalcemia type 1 (ADH1) is caused by heterozygous activating mutations in the calcium-sensing receptor gene (CASR). Whether polymorphisms that are benign in the heterozygous state pathologically alter receptor function in the homozygous state is unknown. Objective: To identify the genetic defect in an adolescent female with a history of surgery for bilateral cataracts and seizures. The patient has hypocalcemia, hyperphosphatemia, and low serum PTH level. The parents of the proband are healthy. Methods: Mutation testing of PTH, GNA11, GCM2, and CASR was done on leukocyte DNA of the proband. Functional analysis in transfected cells was conducted on the gene variant identified. Public single nucleotide polymorphism (SNP) databases were searched for the presence of the variant allele. Results: No mutations were identified in PTH, GNA11, and GCM2 in the proband. However, a germline homozygous variant (c.1631G>A; p.R544Q) in exon 6 of the CASR was identified. Both parents are heterozygous for the variant. The variant allele frequency was near 0.1% in SNP databases. By in vitro functional analysis, the variant was significantly more potent in stimulating both the Ca2+i and MAPK signaling pathways than wild type when transfected alone (P < 0.05) but not when transfected together with wild type. The overactivity of the mutant CaSR is due to loss of a critical structural cation-π interaction. Conclusions: The patient's hypoparathyroidism is due to homozygosity of a variant in the CASR that normally has weak or no phenotypic expression in heterozygosity. Although rare, this has important implications for genetic counseling and clinical management.

Sellar plasmacytoma presenting with symptoms of anterior pituitary dysfunction.

Sellar plasmacytomas are rare and the differential diagnosis with non-functioning pituitary adenomas might be difficult because of clinical and radiological resemblance. They usually present with neurological signs and intact anterior pituitary function. Some may already have or eventually progress to multiple myeloma. We describe a case associated with extensive anterior pituitary involvement, which is a rare form of presentation. A 68-year-old man was referred to our Endocrinology outpatient clinic due to gynecomastia, reduced libido and sexual impotence. Physical examination, breast ultrasound and mammography confirmed bilateral gynecomastia. Blood tests revealed slight hyperprolactinemia, low testosterone levels, low cortisol levels and central hypothyroidism. Sellar MRI showed a heterogeneous sellar mass (56 × 60 × 61 mm), initially suspected as an invasive macroadenoma. After correcting the pituitary deficits with hydrocortisone and levothyroxine, the patient underwent transsphenoidal surgery. Histological examination revealed a plasmacytoma and multiple myeloma was ruled out. The patient was unsuccessfully treated with radiation therapy (no tumor shrinkage). Myeloma ultimately developed, with several other similar lesions in different locations. The patient was started on chemotherapy, had a bone marrow transplant and is now stable (progression free) on lenalidomide and dexamethasone. The presenting symptoms and panhypopituitarism persisted, requiring chronic replacement treatment with levothyroxine, hydrocortisone and testosterone. LEARNING POINTS: Plasmacytomas, although rare, are a possible type of sellar masses, which have a completely different treatment approach, so it is important to make the correct diagnosis.Usually, they present with neurological signs and symptoms and a well-preserved pituitary function, but our case shows that anterior pituitary function can be severely compromised.Making a more extensive evaluation (clinical and biochemical) might provide some clues to this diagnosis.

Malignant paraganglioma presenting with hemorrhagic stroke in a child.

Sympathetic paragangliomas are rare catecholamine-secreting tumors of extra-adrenal origin, and their diagnosis in children is even more infrequent. They usually manifest as hypertension, palpitations, headache, sweating, and pallor. Malignant paragangliomas are identified by the presence of metastasis. Hemorrhagic stroke in the pediatric population is a life-threatening condition with several etiologies. We report here the case of a 12-year-old boy with malignant sympathetic paraganglioma presenting with hemorrhagic stroke. Severe hypertension was found and the patient evolved into a coma. Brain computed tomography scan showed right thalamus hemorrhage with intraventricular extension. After clinical improvement, further investigation revealed elevated catecholamine and metanephrine levels, and 2 abdominal tumors were identified by computed tomography. Resection of both lesions was performed, and histologic findings were consistent with paraganglioma. Multiple metastatic involvement of bones and soft tissues appeared several years later. Genetic testing identified a mutation in succinate dehydrogenase subunit B gene, with paternal transmission. 131I-metaiodobenzylguanidine therapy was performed 3 times with no tumoral response. Our patient is alive, with adequate quality of life, 25 years after initial diagnosis. To our knowledge, this is the first pediatric case of paraganglioma presenting with hemorrhagic stroke. Intracerebral hemorrhage was probably caused by severe hypertension due to paraganglioma. Therefore, we expand the recognized clinical spectrum of the disease. Physicians evaluating children with hemorrhagic stroke, particularly if hypertension is a main symptom, should consider the possibility of catecholamine-secreting tumors. Metastatic disease is associated with succinate dehydrogenase subunit B mutations and, although some patients have poor prognosis, progression can be indolent.

Thyroid tuberculosis with abnormal thyroid function--case report and review of the literature.

OBJECTIVE: To report an extremely rare case of thyroid tuberculosis (TT) with abnormal thyroid function and to review the related literature. METHODS: We present the patient's history, clinical findings, laboratory test results, imaging examinations, cytological data, management, and follow-up. In addition, we perform a review of the previously published cases of TT and give special attention to those with hypothyroidism. RESULTS: A 45-year-old Indian man presented to the outpatient clinic with neck swelling and respiratory and constitutional symptoms. Cervical ultrasound revealed a thyroid nodule and a necrotic right cervical adenopathy. Fine-needle aspiration cytology (FNAC) was performed and purulent material was removed from thyroid and lymph node. In both specimens, the culture was positive for Mycobacterium tuberculosis complex, and a cytological examination revealed epithelioid cell granulomas and necrosis. Mycobacterium tuberculosis complex was also identified by sputum culture. Antibiotic testing revealed sensitivity to all first-line drugs. A diagnosis of disseminated tuberculosis with thyroid and cervical lymph node involvement was made. Thyroid function was consistent with subclinical hyperthyroidism that subsequently evolved to hypothyroidism, requiring thyroid hormone replacement, and reflected tuberculous thyroiditis. Anti-tuberculosis drugs were started with good therapeutic response. CONCLUSION: TT is a rare condition and its association with thyroid function abnormalities is even rarer. To our knowledge this is the third report of hypothyroidism related to TT and the first to identify a period of hyperthyroidism preceding hypothyroidism. Despite its rarity, TT should be considered in the differential diagnosis of neck mass. FNAC is a useful procedure and thyroid function should be monitored.