Summary

Brain metastases as the first clinical presentation of a papillary thyroid carcinoma (PTC) are exceptional, while cavernous angiomas are common cerebral malformations. We report the case of a 36-year-old male with an incidental brain lesion mimicking a cavernous angioma on MRI. Gamma knife radiosurgery was performed, but after 6 months, the patient developed neurological symptoms, and a repeat brain MRI revealed a significant increase in the mass. The patient underwent neurosurgery, and the histological examination of the lesion revealed metastatic carcinoma of thyroid origin. PET–CT and neck ultrasound, subsequently performed, were concordant for the presence of a right lobe nodule and ipsilateral lymph nodes, both with ultrasound features suspicious of malignancy. Total thyroidectomy with central and right lateral neck dissection was performed, and histology confirmed an intrathyroidal multifocal PTC with lymph node metastases. Postoperative radioiodine was administered, and focal uptake within the thyroid bed, without distant metastases or brain remnants, was found on the post-therapeutic whole-body scan. At 2 years from diagnosis, the patient is in good health and undergoes clinical and imaging follow-up.

Learning points

• Brain cavernous angiomas are common cerebral vascular malformations that are usually diagnosed by MRI.

• Despite the high accuracy of MRI, the exam is not pathognomonic, and misdiagnosis cannot be excluded.

• Brain metastases from PTC are very rare; however, they can mimic a cavernous angioma. Therefore, the differential diagnosis should always be considered.

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

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

We describe the case of a 56 year-old woman with the almost simultaneous appearance of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) and a carotid body paraganglioma. Of interest, 6 years earlier, the patient underwent total thyroidectomy due to papillary thyroid carcinoma and, in the meantime, she was submitted to mastectomy to treat an invasive ductal carcinoma of the breast. In order to explain these lesions, an extensive genetic study was performed. Results showed positivity for the presence of the tumor suppressor gene PALB2, whose presence had already been detected in a niece with breast cancer. The patient underwent different procedures to treat the lesions and currently she is symptom-free over 2 years of follow-up.

Learning points:

• The presence of two rare neoplasms in a single person should raise the suspicion of a common etiology.

• To the best of our knowledge, this is the first case that shows the coexistence of DIPNECH and paraganglioma.

• The contribution of the PALB2 gene in the etiology of these rare neoplasms is a possibility.

Summary

Papillary thyroid gland carcinoma is the most common type of malignancy of the endocrine system. Metastases to the pituitary gland have been described as a complication of papillary thyroid cancer in few reported cases since 1965. We report the case of a 68-year-old female patient with a well-differentiated form of thyroid gland cancer. Despite it being the most common malignant cancer of the endocrine system, with its papillary form being one of the two most frequently diagnosed thyroid cancers, the case we present is extremely rare. Sudden cardiac arrest during ventricular fibrillation occurred during hospitalization. Autopsy of the patient revealed papillary carcinoma of the thyroid, follicular variant, with metastasis to the sella turcica, and concomitant sarcoidosis of heart, lung, and mediastinal and hilar lymph nodes. Not only does atypical metastasis make our patient’s case most remarkable, but also the postmortem diagnosis of sarcoidosis makes her case particularly unusual.

Learning points:

• The goal of presenting this case is to raise awareness of the clinical heterogeneity of papillary cancer and promote early diagnosis of unexpected metastasis and coexisting diseases to improve clinical outcomes.

• Clinicians must be skeptical. They should not fall into the trap of diagnostic momentum or accept diagnostic labels at face value. Regardless of the potential mechanisms, clinicians should be aware of the possibility of the coexistence of thyroid cancer and sarcoidosis as a differential diagnosis of lymphadenopathy.

• This case highlights the importance of the diagnostic and therapeutic planning process and raises awareness of the fact that one uncommon disease could be masked by another extremely rare disorder.

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.

Summary

Anaplastic transformation of a primary thyroid tumor whose process can be followed is rare. The objective this study is to report a case of anaplastic transformation of locally advanced papillary thyroid carcinoma after treatment with lenvatinib. A 74-year-old woman consulted a local physician because of cough and bloody sputum. Thyroid cancer with tracheal invasion was suspected on computed tomography (CT) imaging, and she visited our hospital for treatment. We suspected anaplastic thyroid cancer (ATC) and core needle biopsy was performed. Histologic sections of the core needle biopsy showed that the tumor formed a papillary structure, and we diagnosed papillary thyroid carcinoma. Surgery would have been difficult, and we initiated lenvatinib at a low dose of 8 mg/day. CT on day 40 of lenvatinib treatment revealed that the thyroid tumor had shrunk remarkably. CT on day 111 revealed that tumor regrowth and tracheal invasion had been exacerbated. Core needle biopsy was performed, and histologic sections of the core needle biopsy that was performed after regrowth of the tumor showed that individual cancer cells had large, irregular nuclei, and necrosis was also observed. The immunohistochemical findings were negative for thyroglobulin, and only a few cells were positive for thyroid transcription factor 1, and we diagnosed ATC. Anaplastic transformation of the target lesion may be one of the causes of lenvatinib treatment failure in differentiated thyroid carcinoma.

Learning points:

• Anaplastic transformation of a primary thyroid tumor whose process can be followed is rare.

• The resistance mechanism of lenvatinib in treatment for differentiated thyroid carcinoma has not been clarified.

• Anaplastic transformation of the target lesion may be one of the causes of lenvatinib treatment failure in differentiated thyroid carcinoma.

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.