Summary

We report the case of a 76-year-old male with a remote history of papillary thyroid cancer who developed severe paroxysmal headaches in the setting of episodic hypertension. Brain imaging revealed multiple lesions, initially of inconclusive etiology, but suspicious for metastatic foci. A search for the primary malignancy revealed an adrenal tumor, and biochemical testing confirmed the diagnosis of a norepinephrine-secreting pheochromocytoma. Serial imaging demonstrated multiple cerebral infarctions of varying ages, evidence of vessel narrowing and irregularities in the anterior and posterior circulations, and hypoperfusion in watershed areas. An exhaustive work-up for other etiologies of stroke including thromboembolic causes or vasculitis was unremarkable. There was resolution of symptoms, absence of new infarctions, and improvement in vessel caliber after adequate alpha-adrenergic receptor blockade for the management of pheochromocytoma. This clinicoradiologic constellation of findings suggested that the etiology of the multiple infarctions was reversible cerebral vasoconstriction syndrome (RCVS). Pheochromocytoma remains a poorly recognized cause of RCVS. Unexplained multifocal cerebral infarctions in the setting of severe hypertension should prompt the consideration of a vasoactive tumor as the driver of cerebrovascular dysfunction. A missed or delayed diagnosis has the potential for serious neurologic morbidity for an otherwise treatable condition.

Learning points:

• The constellation of multifocal watershed cerebral infarctions of uncertain etiology in a patient with malignant hypertension should trigger the consideration of undiagnosed catecholamine secreting tumors, such as pheochromocytomas and paragangliomas.

• Reversible cerebral vasoconstriction syndrome is a serious but reversible cerebrovascular manifestation of pheochromocytomas that may lead to strokes (ischemic and hemorrhagic), seizures, and cerebral edema.

• Alpha-adrenergic receptor blockade can reverse cerebral vasoconstriction and prevent further cerebral ischemia and infarctions.

• Early diagnosis of catecholamine secreting tumors has the potential for reducing neurologic morbidity and mortality in patients presenting with cerebrovascular complications.

Summary

In most developed countries, breast carcinoma is the most common malignancy in women and while thyroid cancer is less common, its incidence is almost three to five times greater in women than in men. Since 1966, studies have demonstrated an association between thyroid and breast cancer and despite these studies, the mechanism/s by which they are related, remains unclear. We present a case of a 56-year-old lady who initially presented in 2014 with a screen detected left breast carcinoma but was subsequently found to have occult metastatic thyroid cancer to the axilla, diagnosed from a sentinel node biopsy from the primary breast procedure. The patient underwent a left mastectomy, left axillary dissection and total thyroidectomy followed by three courses of radioactive iodine ablation. Despite this, her thyroglobulin level continued to increase, which was secondary to a metastatic thyroid cancer parasternal metastasis. Breast and thyroid cancer presents metachronously or synchronously more often than by chance. With improving mortality in primary cancers, such as breast and differentiated thyroid cancer, it is likely that as clinicians, we will continue to encounter this association in practice.

Learning points:

• There has been a long-standing observation of an association between breast and thyroid cancer although the exact mechanism of this association remains unclear.

• Our patient presented with thyroid cancer with an incidental diagnosis from a sentinel node biopsy during her primary breast operation for breast cancer and was also found to have a parasternal distant bony metastasis.

• Thyroid axillary metastases are generally rare.

• The interesting nature in which this patient’s metastatic thyroid carcinoma behaved more like a breast carcinoma highlights a correlation between these two cancers.

• With improving mortality in these primary cancers, clinicians are likely to encounter this association in clinical practice.

• Systemic therapy for metastatic breast and thyroid cancers differ and therefore a clear diagnosis of metastasis is crucial.

Summary

Isolated, adult-onset central hypothyroidism is very rare, and its diagnosis can be challenging. A 42-year-old patient was referred for evaluation of a 2.8 cm thyroid nodule. She referred symptoms that could be attributed to hypothyroidism and thyroid tests showed low TSH and normal-low levels of free T4. However, evaluation of the remaining pituitary hormones and pituitary MRI were normal, yet a radionuclide scanning revealed that the thyroid nodule was ‘hot’ and the tracer uptake in the remaining thyroid tissue was suppressed. Interpretation of these studies led to a misdiagnosis of subclinical hyperthyroidism and the patient was treated with radioiodine. Soon after treatment, she developed a frank hypothyroidism without appropriate elevation of TSH and the diagnosis of central hypothyroidism was made a posteriori. Long term follow-up revealed a progressive pituitary failure, with subsequent deficiency of ACTH and GH. This case should alert to the possibility of overlooking central hypothyroidism in patients simultaneously bearing primary thyroid diseases able to cause subclinical hyperthyroidism.

Learning points:

• Although rarely, acquired central hypothyroidism can occur in the absence of other pituitary hormone deficiencies.

• In these cases, diagnosis is challenging, as symptoms are unspecific and usually mild, and laboratory findings are variable, including low, normal or even slightly elevated TSH levels, along with low or low-normal concentrations of free T4.

• In cases with low TSH levels, the coexistence of otherwise common disorders able to cause primary thyroid hyperfunction, such as autonomous nodular disease, may lead to a misdiagnosis of subclinical hyperthyroidism.

Summary

We report a rare case of concurrent medullary thyroid cancer (MTC) and papillary thyroid cancer (PTC) with intermixed disease in several of the lymph node (LN) metastases in a patient who was subsequently diagnosed with clear cell renal cell carcinoma (RCC). A 56 year old female presented with dysphagia and was found to have a left thyroid nodule and left superior cervical LN with suspicious sonographic features. Fine needle aspiration biopsy (FNAB) demonstrated PTC in the left thyroid nodule and MTC in the left cervical LN. Histopathology demonstrated multifocal PTC with 3/21 LNs positive for metastatic PTC. One LN in the left lateral neck dissection exhibited features of both MTC and PTC within the same node. In the right lobe, a 0.3 cm focus of MTC with extra-thyroidal extension was noted. Given persistent calcitonin elevation, a follow-up ultrasound displayed an abnormal left level 4 LN. FNAB showed features of both PTC and MTC on the cytopathology itself. The patient underwent repeat central and left radical neck dissection with 3/6 LNs positive for PTC in the central neck and 2/6 LNs positive for intermixed PTC and MTC in the left neck. There was no evidence of distant metastases on computed tomography and whole body scintigraphy, however a 1.9 x 2.5 cm enhancing mass within the right inter-polar kidney was discovered. This lesion was highly suspicious for RCC. Surgical pathology revealed a 2.5 cm clear cell RCC, Fuhrman grade 2/4, with negative surgical margins. She continues to be observed with stable imaging of her triple malignancies.

Learning points:

• Mixed medullary-papillary thyroid neoplasm is characterized by the presence of morphological and immunohistochemical features of both medullary and papillary thyroid cancers within the same lesion. Simultaneous occurrence of these carcinomas has been previously reported, but a mixed disease within the same lymph node is an infrequent phenomenon.

• Prognosis of mixed medullary-papillary thyroid carcinomas is determined by the medullary component. Therefore, when PTC and MTC occur concurrently, the priority should be given to the management of MTC, which involves total thyroidectomy and central lymph node dissection.

• Patients with thyroid cancer, predominantly PTC, have shown higher than expected rates of RCC. To our knowledge, this is the first report describing the combination of MTC, PTC, and RCC in a single patient.

Summary

Struma ovarii is a rare, usually benign ovarian tumour with malignancy occurring in <5% of cases. Metastases, particularly seeding to bone, are extremely rare. Presentation is variable but often features local pain and/or ascites and hyperthyroidism may occur. It is not established how to best treat and follow patients with extensive disease. Case reports of radioiodine (I¹³¹) ablative therapy following thyroidectomy have shown reduced recurrence. We describe the case of a 33-year-old woman who presented with bone pain and was diagnosed with skeletal metastases with features of follicular thyroid carcinoma. However, thyroid pathology was benign. She recalled that 5 years prior, an ovarian teratoma was excised, classified at that time as a dermoid cyst. Retrospective review of this pathology confirmed struma ovarii without obvious malignant features. The patient was found to have widespread metastases to bone and viscera and her thyroglobulin was >3000 µg/L following recombinant TSH administration prior to her first dose of I¹³¹. At 25 months following radioiodine treatment, she is in remission with an undetectable thyroglobulin and clear I¹³¹ surveillance scans. This case demonstrates an unusual presentation of malignant struma ovarii together with challenges of predicting metastatic disease, and demonstrates a successful radioiodine regimen inducing remission.

Learning points:

• Malignant transformation of struma ovarii (MSO) is extremely rare and even rarer are metastatic deposits in bone and viscera.

• MSO can be difficult to predict by initial ovarian pathology, analogous to the difficulty in some cases of differentiating between follicular thyroid adenoma and carcinoma.

• No consensus exists on the management for post operative treatment of MSO; however, in this case, three doses of 6Gbq radioiodine therapy over a short time period eliminated metastases to viscera and bone.

• Patients should continue to have TSH suppression for ~5 years.

• Monitoring thyroglobulin levels can predict recurrence.

Summary

Graves’ disease is associated with tachydysrythmia, cardiac ischaemia and cardiomyopathy – all uncommon in young adults without previous cardiac disease. We present three young individuals who developed cardiac complications after periods of uncontrolled Graves’ disease. Subject 1: A 34-year-old female had severe thyrotoxic symptoms for weeks. Investigations showed fT4: 98.4 (11–25 pmol/L), fT3: 46.9 (3.1–6.8 pmol/L), TSH <0.01 (0.27–4.2 mU/L) and thyrotrophin receptor antibody (TRAb): 34.8 (<0.9 U//l). She had appropriate treatment but several weeks later she became breathless despite improving thyroid function. Echocardiography showed a pericardial effusion of 2.9 cm. She responded well to steroids and NSAIDs but developed active severe Graves’ orbitopathy after early total thyroidectomy. Subject 2: A 28-year-old male developed thyrotoxic symptoms (fT4: 38 pmol/L, fT3: 13.9 pmol/L, TSH <0.01 (for over 6 months) and TRAb: 9.3 U/L). One month after starting carbimazole, he developed acute heart failure (HF) due to severe dilated cardiomyopathy – EF 10–15%. He partially recovered after treatment – EF 28% and had early radioiodine treatment. Subject 3: A 42-year-old woman who had been thyrotoxic for several months (fT4: 54.3; fT3 >46.1; TSH <0.01; TRAb: 4.5) developed atrial fibrillation (AF) and heart failure. Echocardiography showed cardiomegaly – EF 29%. She maintains sinus rhythm following early total thyroidectomy (EF 50%). Significant cardiac complications may occur in previously fit young adults, who have had uncontrolled Graves’ disease for weeks to months. Cardiac function recovers in the majority, but early definitive treatment should be discussed to avoid Graves’ disease relapse and further cardiac decompensation.

Learning points:

• Cardiac complications of Graves’ disease are uncommon in young adults without previous cardiac disease.

• These complications may however occur if Graves’ disease had been poorly controlled for several weeks or months prior to presentation.

• Persistent symptoms after adequate control should alert clinicians to the possibility of cardiac disease.

• Specific treatment of Graves’ disease and appropriate cardiac intervention results in complete recovery in the majority and carries a good prognosis.

• Early definitive treatment should be offered to them to prevent cardiac decompensation at times of further relapse.

Summary

This case is the first to describe a patient who experienced concomitant agranulocytosis and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis as an adverse effect of propylthiouracil treatment for Graves’ disease. A 42-year-old female with Graves’ disease presented to the emergency department (ED) with a 2-week history of fevers, night sweats, transient lower limb rash, arthralgia, myalgia and fatigue. She had been taking propylthiouracil for 18 months prior to presentation. On admission, agranulocytosis was evident with a neutrophil count of 0.36 × 10⁹/L and immediately propylthiouracil was stopped. There was no evidence of active infection and the patient was treated with broad-spectrum antibodies and one dose of granulocyte colony-stimulation factor, resulting in a satisfactory response. On further investigation, ANCAs were positive with dual positivity for proteinase 3 and myeloperoxidase. There was no evidence of end-organ damage secondary to vasculitis, and the patient’s constitutional symptoms resolved completely on discontinuation of the drug precluding the need for immunosuppressive therapy.

Learning points:

• Continued vigilance and patient education regarding the risk of antithyroid drug-induced agranulocytosis is vital throughout the course of treatment.

• ANCA-associated vasculitis is a rare adverse effect of antithyroid drug use.

• Timely discontinuation of the offending drug is vital in reducing end-organ damage and the need for immunosuppressive therapy in drug-induced ANCA-associated vasculitis.

• Similarities in the pathogenesis of agranulocytosis and drug-induced ANCA-associated vasculitis may offer insight into an improved understanding of vasculitis and agranulocytosis.

Summary

A 40-year-old woman was hospitalised at 25-week gestation following a diagnosis of severe symptomatic hypercalcaemia (adjusted serum calcium 3.02 mmol/L). A diagnosis of primary hyperparathyroidism (PHP) was made on the basis of elevated parathyroid hormone (PTH) 11.2 pmol/L (reference range 1.5–6.9) and exclusion of familial hypocalciuric hypercalcaemia. Ultrasound examination of the neck did not convincingly demonstrate an abnormal or enlarged parathyroid gland and parathyroid scintigraphy was not performed due to maternal choice relating to perceived radiation risk to the foetus. At neck exploration during the 28th week of pregnancy a right lower pole parathyroid lesion was excised together with two abnormal lymph nodes (largest 1.6 cm). Histology confirmed a parathyroid adenoma and also papillary thyroid carcinoma deposits in the two resected lymph nodes. Post-operatively, levels of adjusted serum calcium normalised and pregnancy progressed uneventfully to term. Total thyroidectomy was performed 2 weeks after delivery revealing two small foci of papillary micro-carcinoma (largest 2.3 mm, one in each thyroid lobe) with no evidence of further metastatic tumour in lymph nodes removed during functional neck dissection. Radioiodine remnant ablation (RRA) was performed 2 months post thyroidectomy to allow for breast involution. The patient remains in full clinical and biochemical remission 9 years later. We present and review the difficult management decisions faced in relation to the investigation and treatment of PHP in pregnancy, further complicated by incidentally discovered locally metastatic pT1aN1aM0 papillary thyroid carcinoma.

Learning points:

• PHP may have serious consequences during pregnancy and usually requires surgical management during pregnancy to reduce the risk of maternal and foetal complications. The indications for and optimal timing of surgical management are discussed.

• Localisation by parathyroid scintigraphy is controversial during pregnancy: modified dose regimes may be considered in preference as an alternative to unguided neck exploration.

• Breastfeeding is contraindicated for 6–8 weeks before radioactive-iodine remnant ablation (RRA) to prevent increased breast uptake. Breastfeeding is further contra-indicated until after a subsequent pregnancy.

• Incidentally discovered differentiated thyroid carcinoma (DTC) in cervical lymph nodes in some cases may be managed expectantly because in one quarter of thyroidectomies the primary tumour remains occult.

Summary

A 74-year-old man was referred to the Endocrinology Unit because of multinodular goiter. The dominant nodule (1.7 × 1.9 × 2.4 cm), at the medium-superior third of the left lobe, was inhomogeneously hypoechoic, with irregular margins, macrocalcifications and intranodular vascularization. Fine-needle aspiration biopsy (FNAB) was performed. The cytological diagnosis was TIR 2, benign, according to the 2013 Italian thyroid cytology classification system. Moderately high serum calcitonin (s-Ct) (61.5 pg/mL, n.r. 0–7.5) and normal CEA were detected. The Ct level in FNAB wash-out fluid (Ct-FNAB) was 1450 pg/mL. Based on s-Ct and Ct-FNAB levels, patient underwent total thyroidectomy. Macroscopically, a dominant circumscribed nodule of 2 ecm was described; the histological and immunohistochemical features identified medullary thyroid carcinoma (MTC) with paraganglioma (PG)-like pattern positive for Ct, CEA and chromogranin and negative for S-100 sustentacular cells (SC). Moreover, papillary carcinoma of 3 mm in the right lobe was also associated. No areas of hyperaccumulation of the tracer were documented at Ga68 PET/CT. No RET-proto-oncogene mutations were found. Post-surgery s-Ct levels were within normal range (4 pg/mL). Two years after thyroidectomy, the patient is still disease-free. We reported a case of sporadic and rare variant of MTC: this is the ninth described case of PG-like MTC. In this case, cytologically benign, the clinical suspicion arose from high Ct values at FNAB wash-out fluid. Even if clinical behavior of this variant seems indolent, additional studies are necessary to understand prognoses and predictive factors.

Learning points:

• Several unusual histological variants of medullary thyroid carcinoma (MTC) have been described such as spindle cell, giant cell, clear cell, melanotic, squamous, angiosarcoma-like variants; even rarer is the paraganglioma (PG)-like pattern.

• We here describe a case of medullary PG-like thyroid carcinoma in a 74-year-old man. This is a rare histological variant of MTC hardly diagnosed by cytology, since immunohistochemical investigations are necessary.

• Measurement of calcitonin both in serum and in wash-out fluid from fine-needle aspiration could be an additional tool for an early and non-invasive identification of these variants.

Learning points:

• Metastatic PTC should be considered in the differential diagnosis of a recurrent solitary cystic cervical lymph node.

• A dedicated thyroid ultrasound is the preferred modality for identifying thyroid lesion over computed tomography.

• There is a risk of non-diagnostic cytology following FNA for cystic neck lesions, largely predicted by the cyst content of the nodule.