Pituitary metastasis as a presenting manifestation of silent systemic malignancy: A retrospective analysis of four cases

Metastatic diffuse follicular variant papillary thyroid cancer without cervical lymph node metastasis presenting with symptoms related to hypopituitarism

In this article, we present a case of diffuse follicular variant papillary thyroid carcinoma with pituitary metastasis, which is a rare cause of pituitary metastasis. The follicular variant of papillary thyroid carcinoma is an uncommon variant of papillary carcinoma. A 74-year-old male was presented with weakness, fatigue, and a decreased appetite. The patient was diagnosed with secondary adrenal and thyroid insufficiencies. Imaging revealed a pituitary mass with suprasellar extension, right cavernous sinus invasion, and optic chiasm compression. Thyroid ultrasonography revealed a nodule with a maximum size of 7.2cm in the right lobe. Cytological examination via fine-needle aspiration suggested papillary thyroid cancer. Total thyroidectomy with central and right lateral neck dissection confirmed the diagnosis of diffuse follicular variant of papillary thyroid carcinoma. Owing to visual field defects, the patient underwent transsphenoidal surgery. Histological and immunohistochemical evaluations confirmed pituitary metastasis from the papillary thyroid cancer. Radioactive iodine treatment and gamma knife radiotherapy of the pituitary gland were performed. The initiation of sorafenib treatment was deemed appropriate during the follow-up. A significant decrease in the thyroglobulin levels was observed after sorafenib treatment. Pituitary metastasis should be considered in patients diagnosed with hypopituitarism and pituitary lesions at initial evaluation. The presence of visual field defects may be an indication for neurosurgical intervention and guide both diagnosis and treatment. The management of papillary thyroid cancer and the role of treatment modalities in prognosis depend on the biological behavior of the tumor. Early diagnosis and multidisciplinary management are crucial for the treatment of these patients.

Apoplexy in sellar metastasis from papillary thyroid cancer: A case report and literature review

Background:

Pituitary metastasis from papillary thyroid cancer (PTC) is rare and only a few cases have been reported.

Case Description:

We report the case of a patient who presented with visual dysfunction and panhypopituitarism. Magnetic resonance imaging revealed a pituitary tumor and hydrocephalus. Transsphenoidal surgery had been indicated, but his surgery had been postponed due to COVID-19 pandemic. During that waiting period, he showed pituitary apoplexy with consciousness disturbance, resulting in acute adrenal insufficiency and diabetes insipidus. He was urgently hospitalized and underwent transsphenoidal surgery. Rapid and permanent pathological examinations have confirmed metastasis of PTC to the pituitary. The patient also underwent serial thyroidectomy. He was also suspected to have secondary hydrocephalus and underwent lumboperitoneal shunting after excluding cerebrospinal fluid metastasis. Thereafter, his cognitive dysfunction and performance status improved dramatically.

Conclusion:

To the best of our knowledge, this is the first patient with PTC who developed pituitary apoplexy secondary to metastasis.

Melanoma metastasis to a nonfunctioning pituitary macroadenoma: illustrative case

BACKGROUND

Metastases to the central nervous system are often multiple in number and typically favor the gray-white matter junction. Collision tumors, defined as the coexistence of two morphologically different tumors, such as metastases to a known pituitary adenoma (PA), are exceedingly rare. Only a few reported cases of metastases to a PA exist in the literature.

OBSERVATIONS

The authors present the case of a 64-year-old man with a known history of stage IV metastatic melanoma who was found to have hypermetabolic activity in the sellar region on surveillance positron emission tomography. On laboratory evaluation, he had clear evidence of pituitary axis dysfunction without diabetes insipidus. Subsequent magnetic resonance imaging showed a 2.4-cm sellar mass with features of a pituitary macroadenoma and internal hemorrhage, although no clinical symptoms of apoplexy were noted. He underwent a transsphenoidal endoscopic endonasal approach for resection of the sellar lesion. Final pathology showed a collision tumor with melanoma cells intermixed with PA cells.

LESSONS

Histological analysis verified the rare presence of a collision tumor of a melanoma metastasis to a nonfunctional pituitary macroadenoma. Metastasis to a preexisting PA, although rare, should be considered in the differential diagnosis in patients with sellar lesions and a known cancer history.

Diabetes insipidus and panhypopituitarism as a first presentation of silent adenocarcinoma of lung: a case report and literature review

BACKGROUND

Pituitary metastasis is a rare condition with a poor prognosis. Very few patients with pituitary metastasis are symptomatic. It is often associated with presence of co-existing metastases to other organs. Isolated pituitary metastasis as the first presentation of primary malignancy is uncommon.

CASE PRESENTATION

A 72-year-old woman presented with a 2-month history of polyuria, increasing thirst and unexplained weight loss. Esophagogastroduodenoscopy (EGD) was scheduled as part of the investigation. She was kept nil per os for 10 h prior to EGD, after which she developed alteration of consciousness. Further investigation revealed hypernatremia with sodium level of 161 mmol/L and low urine osmolality of 62 mOsm/kg. Her urine output was 300 mL per hour. Diabetes insipidus (DI) was diagnosed based on evidence of polyuria, hypernatremia, and low urine osmolality. Her urine output decreased and urine osmolality increased to 570 mOsm/kg in response to subcutaneous desmopressin acetate, confirming central DI. Pituitary magnetic resonance imaging showed a heterogeneous gadolinium enhancing lesion at the sellar and suprasellar regions, measuring 2.4 × 2.6 × 3.9 cm compressing both the hypothalamus bilaterally and the inferior aspect of optic chiasm as well as displacing the residual pituitary gland anteriorly. The posterior pituitary bright spot was absent. These MRI findings suggested pituitary macroadenoma. There were also multiple small gadolinium-enhancing lesions up to 0.7 cm in size with adjacent vasogenic brain edema at the subcortical and subpial regions of the left frontal and parietal areas, raising the concern of brain metastases. Pituitary hormonal evaluation was consistent with panhypopituitarism. Histopathological and immunohistochemical studies of the pituitary tissue revealed an adenocarcinoma, originating from the lung. Computed tomography of the chest and abdomen was subsequently performed, showing a 2.2-cm soft tissue mass at the proximal part of right bronchus. There was no evidence of distant metastases elsewhere. The final diagnosis was adenocarcinoma of the lung with pituitary metastasis manifesting as panhypopituitarism and central DI. Palliative care along with hormonal replacement therapy was offered to the patient. She died 4 months after diagnosis.

CONCLUSION

Diagnosis of pituitary metastasis is challenging, especially in patients with previously undiagnosed primary cancer. It should be considered in the elderly patients presenting with new-onset central DI with or without anterior pituitary dysfunction.

What's in the Image? Pituitary Metastasis from Papillary Carcinoma of the Thyroid: A Case Report and a Comprehensive Review of the Literature

A 67-year-old female patient presented with visual field impairment and hyperprolactinemia. Imaging revealed a sellar and suprasellar mass and during the evaluation of the sellar lesion, papillary thyroid carcinoma (PTC) was diagnosed by fine-needle aspiration biopsy in a long-standing euthyroid multinodular goiter. The patient did not have a previous history of PTC. Total thyroidectomy confirmed the diagnosis of PTC. Due to progressive visual loss, she underwent transcranial surgery for decompression of the optic chiasm. Pituitary metastasis from PTC was confirmed, histologically and immunohistochemically. In literature, overall 13 cases, including ours, with PTC metastasis to the sellar region have been reported. Most were women, with a median age of 56 years. Two thirds of patients were previously diagnosed with PTC. The presence of other distant metastases was confirmed in less than half of the patients. Only 2 and our patient had immunohistochemical confirmation of PTC metastasis to the sellar region. The presenting signs and symptoms included: visual field defects, ophthalmoplegia, and anterior pituitary hormone deficiencies. In conclusion, this is a rare case of metastatic PTC to the sellar region unequivocally confirmed by immunohistochemistry in whom the disease first presented with a sellar and suprasellar mass.