Bocio endotorácico remanente a seis años de postiroidectomía total / Unusual endothoracic goiter after six year of total post-thyroidectomy

El bocio endotorácico remanente se define como el hallazgo de tejido tiroideo mediastinal después de una tiroidectomía total. Es una entidad infrecuente y generalmente el tumor se encuentra en el mediastino anterior, en posición retroesternal. Se presenta el caso de un paciente con bocio endotorácico remanente postiroidectomía total diagnosticado 6 años después. Se le realizó una exéresis a la enferma de la lesión sin complicaciones intra ni posoperatorias(AU)

Unusual endothoracic goiter is defined as the finding of mediastinal thyroid tissue after total thyroidectomy. It is uncommon and generally the tumor is located in the anterior mediastinum at retrosternal position. This was a patient with unusual endothoracic goiter after total thyroidectomy and diagnosed six years later. The lesion was excised with no intraoperative or postoperative complications(AU)

Approach to management of the patient with primary or secondary intrathoracic goiter.

Intrathoracic (substernal) goiter, depending on definition, is seen in up to 45% of all patients operated for goiter. It can either be primary (ectopic thyroid tissue detached from a cervical thyroid mass), which is very rare (1%), or (more commonly) secondary, where a portion of the goiter extends retrosternally. There is no consensus on diagnostic or therapeutic management, partly because many are asymptomatic. Classification involves functional characterization with serum TSH and morphological characterization with diagnostic imaging and cytology to rule out malignancy, which is not more common than in cervical goiters. Pulmonary function is often affected in asymptomatic individuals also. Therefore, but also because natural history is continuous growth and evolution from euthyroidism to hyperthyroidism, most experts recommend therapy. In primary as well as secondary intrathoracic goiter, the therapy of choice is total/near-total thyroidectomy and subsequent levothyroxine substitution. Data suggest that complications are only slightly more prevalent than in cervical goiters. Although levothyroxine is not recommended for goiter shrinkage, there is increasing focus on radioactive iodine as an alternative to surgery in secondary intrathoracic goiters. Here it can reduce thyroid size by on average 40% after 1 yr and improve respiratory function and quality of life. Recent studies show that recombinant human TSH, currently used off-label, can augment the radioiodine-related goiter shrinkage by 30-50%. With currently used doses of recombinant human TSH, the side effects, besides hypothyroidism, are rare and mild. Future studies should also explore the use of radioiodine in primary intrathoracic goiter and compare surgery and radioiodine, head to head.

Tc-99m pertechnetate scintigraphy before and after potassium perchlorate administration for the diagnosis of retrosternal goiter.

A 52-year-old woman was hospitalized because of dyspnea and dysphagia. Thoracic computed tomography revealed a retrotracheal mass. Tc-99m pertechnetate scintigraphy showed intense accumulation of radioactivity corresponding to the mediastinal mass detected by computed tomography. Repeated Tc-99m pertechnetate scintigraphy performed after oral administration of potassium perchlorate (KCLO4) revealed complete disappearance of the radioactive accumulation in the mediastinum, suggesting that the retrotracheal mass was a retrosternal goiter. Subsequent surgical removal and analysis of the mass showed it was indeed a retrosternal goiter. This case highlights the importance of Tc-99m pertechnetate thyroid scintigraphy with and without KCLO4 administration as a simple, accurate, and cost-effective imaging method to diagnose retrosternal goiter.

[Monosymptomatic hyperthyroidism and TSH-producing adenoma: successful therapy with octreotide]. / Monosymptomatische Hyperthyreose und TSH-produzierendes Adenom: Erfolgreiche Therapie mit Octreotid.

HISTORY AND FINDINGS: Magnetic resonance imaging (MRI) of the central nervous system was performed on a 72-year-old woman who was hyperthyroid without suppression of the thyroid-stimulating hormone (TSH) and had complained of a recent onset of headaches. MRI demonstrated a space-occupying lesion, 1 cm in diameter, in the anterior pituitary. The clinical symptoms were marked by a long-standing monosymptomatic illness of rapidly changing mood swings with depressive and manic phases. INVESTIGATIONS: Endocrinological-biochemical tests showed hyperthyroidism (fT3 10.55 pmol/l and fT4 39 pmol/l) but no TSH suppression (TSH: 2.9 microU/ml). Octreotide scintigraphy documented an activity-rich area in the anterior pituitary and the upper anterior mediastinum. Mediastinal MRI revealed a 5 cm space-occupying mass lying on the right atrium. 131I scintigraphy identified the mass as a retrosternal goitre. TREATMENT AND COURSE: As an operation on the anterior pituitary would have carried a high risk for the patient who was in a poor general condition and she had refused to be operated, treatment with octreotide, a long-acting somatostatin analogue, was initiated. This achieved a euthyroid state with partly suppressed TSH, and the patient's emotional swings ceased. CONCLUSION: If hyperthyroidism coexists with non-suppressed TSH levels, a TSH-producing hypophyseal adenoma should be considered in the differential diagnosis despite its rarity. Octreotide administration is an effective and safe treatment and is the method of choice, especially when there are contraindications to surgical resection of the anterior pituitary.

[A case of mediastinal goiter with hyperthyroidisms].

A 65-years-old woman admitted to the hospital in order to treat of the mediastinal tumor, but she suffered from palpitation, slight fever, sweating, uneasiness, sleeplessness and weightloss. On the physical examination, she was experiencing tachycardia, fevering (37.2 approximately 37.6 degrees C). Skin was moist but had no exophtalmos or neck tumor. Chest X-ray showed an abnormal shadow in the upper mediastinum. On chest CT, a tumor mass (9 x 5 x 4 cm) with cystic regions and scattered calcifications occupied from anterior to posterior mediastinum. The tumor compressed trachea to the left and right brachiocephalic vein and SVC to the right. Lower portion of the tumor intruded into behind of the trachea. Lymph node swelling of mediastinum was also detected. Results of general laboratory examination were within normal limits. Thyroid function test revealed hyperthyroidism; T3U 58%, free T3 24.4 pg/ml, free T4 6.0 ng/dl and thyroglobulin 967 mg/dl, but TSH was < 0.01 microIU/ml. After daily administration of methimazole (300 mg/day) for 4 weeks, thyroid function became to normal level and symptoms of hyperthyroidism was disappeared. The tumor was completely extirpated with right hemithyroidectomy and lymph node dissection under neck colla incision and median sternotomy. Pathological finding of the tumor showed follicular-fetal adenoma of thyroid with hyaloid degeneration and cystic change. There was no finding suspected of Graves' disease. She is well without any complications for 8 months after operation. Some discussion of the literature was mentioned.

Transient superior vena cava syndrome due to propylthiouracil therapy in intrathoracic goiter.

Intrathoracic goiter is a rare cause of superior vena cava syndrome. We present the findings in a patient in whom the syndrome was precipitated by therapy with propylthiouracil and remitted on withdrawal of the medication. The superior vena cava syndrome did not recur on medical management, suggesting that surgery is not always indicated in this setting.