Summary

Hypercalcaemia is a common complication seen in malignancy, frequently due to paraneoplastic parathyroid hormone-related peptide production or osteolytic bony metastases. We present a 58-year-old female with immunotherapy-mediated hypophysitis causing secondary cortisol deficiency resulting in severe glucocorticoid-responsive hypercalcaemia. Whilst hypophysitis is a well recognised adverse event in those receiving immunotherapy for advanced malignancy, it does not typically present with hypercalcaemia. The mechanism responsible for hypercalcaemia due to hypocortisolaemia has not been fully elucidated although hypotheses include the effects of volume depletion and thyroxine’s action on bone. Prompt treatment with glucocorticoids caused an improvement in the patient’s symptoms and corrected her hypercalcaemia which later returned after an attempted glucocorticoid wean. With the increasing uptake of immunotherapy, clinicians should be aware of this unusual presentation of immunotherapy-related hypophysitis and secondary hypocortisolaemia which can be life-threatening if the diagnosis is delayed.

Learning points

• Immunotherapy can cause inflammation of the pituitary gland resulting in secondary hypocortisolaemia, which can, though rarely, present as hypercalcaemia.

• Secondary hypocortisolaemia requires prompt recognition and treatment with glucocorticoids. Glucocorticoid replacement leads to rapid clinical and biochemical improvement in these patients.

• The differential diagnosis for glucocorticoid-responsive hypercalcaemia extends beyond granulomatous disorders (e.g. sarcoidosis, tuberculosis) to adrenocorticotrophic hormone and cortisol deficiency, particularly in patients receiving immunotherapy.

• Hypocortisolaemia can lead to hypercalcaemia through various proposed mechanisms. Low serum glucocorticoids are associated with reduced blood volume, thus reducing renal calcium excretion. In addition, without glucocorticoid’s inhibitory action, thyroxine appears to drive calcium mobilisation from bone.

Summary

Cushing’s disease or pituitary adrenocorticotropic hormone (ACTH)-dependent Cushing’s syndrome is considered a rare condition. It is caused by hypersecretion of the ACTH by a pituitary adenoma that ultimately induces endogenous hypercortisolism by stimulating the adrenal glands. It is responsible for significant morbidity and mortality. The clinical signs and symptoms of hypercortisolism are usually common and non-specific including obesity, moon face, hypertension, hirsutism and facial plethora. The association between Cushing’s disease and calcinosis cutis which is defined as dystrophic calcium deposition in the skin and subcutaneous tissues is extremely rare. To the best of our knowledge, it has never been described previously in humans, probably like a symptom or complication of chronic and severe hypercortisolism. In this paper, we report a case of a 30-year-old female diagnosed with Cushing’s disease and presented bilateral leg’s calcinosis cutis complicated with ulceration. The evolution was favorable and the complete cicatrization was obtained 12 months following the suppression of systemic glucocorticoid excess.

Learning points

• Calcinosis cutis is common in autoimmune connective diseases. However, to our knowledge, it has never been reported in humans with Cushing’s disease.

• Given the rarity of this association, the diagnostic approach to calcinosis cutis must exclude the other etiologies.

• Calcinosis cutis is challenging to treat with no gold standard therapy. In our case, the use of the combination of colchicine and bisphosphonates does not significantly improve the patient’s outcomes. In fact, we suppose that without treating the endogenous hypercortisolism, the calcinosis cutis will not resolve.

Summary

Factitious Cushing’s syndrome (CS) is a very rare form of Münchausen syndrome. Its presentation and course are extremely heterogeneous, and diagnosis is generally challenging. We report the case of a 52-year-old woman who was initially investigated because of the occurrence of cushingoid features. Nevertheless, endocrine work-up showed very low morning plasma ACTH and serum cortisol levels. In addition, it also demonstrated central hypopituitarism and hypogonadotropic hypogonadism. Head MRI showed a small pituitary mass. Based on these results, and probably overlooking the initial clinical suspicion, general practitioner (GP) referred the patient to our Endocrine Unit for hypopituitarism. At inspection, moon face, central obesity, and bruising were evident. Multiple ulcerative skin lesions were also concentrated in the right arm and leg. Dermatology evaluation suggested that the lesions were self-provoked. For several days, the patient denied the assumption of corticosteroids, but we finally discovered that the GP’ nurse had prescribed betamethasone without the GP’s knowledge for about 2 years. In conclusion, the surreptitious assumption of corticosteroids is very rare, but the physicians should be aware that pituitary function could be impaired by high doses of corticosteroids, mimicking hypopituitarism. In these patients, a multidisciplinary approach and environmental investigation can be useful to diagnose factitious CS.

Learning points

• Surreptitious assumption of corticosteroids can cause heterogeneous presentation, ranging from Cushing’s syndrome to multiple hypopituitarism.

• Suppression of ACTH and cortisol levels in a patient with cushingoid features firstly suggests surreptitious assumption of corticosteroids.

• A multidisciplinary approach can be extremely useful in patients with suspected factitious Cushing’s syndrome.

• Sometimes, to prove surreptitious assumption of corticosteroids needs environmental investigation.

Summary

We observed a novel therapeutic response with cabergoline in a male patient with a dopamine-secreting head and neck paraganglioma (HNPGL), macroprolactinoma and germline succinate dehydrogenase C mutation (SDHC). The macroprolactinoma was treated with cabergoline which gave an excellent response. He was found to have raised plasma 3-methoxytyramine of 1014 pmol/L (NR: 0–180 pmol/L); but it was unclear if this was a drug-induced phenomenon from dopamine agonist (DA) therapy. Cabergoline was stopped for 4 weeks and the 3-methoxytyramine level increased significantly to 2185 pmol/L, suggesting a biochemical response of his HNPGL. Subsequently, Gallium-68 Dotatate PET and MRI (Gallium-68 Dotatate PET/MRI) demonstrated a second lesion in the sacrum. Both the HNPGL and metastatic sacral deposit received external beam radiotherapy with a good biochemical and radiological response.

Conclusion

Our case report highlights the rare potential of germline SDHC mutations causing metastatic paraganglioma and concurrent pituitary tumours. Cabergoline treatment may lower elevated 3-methoxytyramine levels and, therefore, mask the biochemical evidence of metastatic disease but also may have therapeutic relevance in dopamine-secreting pheochromocytomas/paragangliomas (PPGLs).

Learning points

• Several neuroendocrine tumours (NETs) express dopamine D2 and D4 receptors. In this case report, cabergoline significantly reduced plasma 3-methoxytyramine level in a patient with functional HNPGL. Cabergoline might have therapeutic relevance in dopamine-secreting PPGLs.

• Paragangliomas associated with SDHC mutation classically present with asymptomatic non-functional HNPGL and have rare metastatic potential.

• The association of pheochromocytoma or paraganglioma and pituitary adenoma is now a well-described rare association (<1%), designated as the three P association. While the three P association is most commonly seen with succinate dehydrogenase B and D mutations, it has also been described in patients with SDHA and SDHC mutations.

• Cabergoline treatment may lower elevated 3-methoxytyramine levels and mask the biochemical evidence of metastatic disease. Regular functional imaging with Gallium-68 Dotatate PET/MRI provides better evidence of metastatic disease.

Summary

Ectopic adrenocorticotropic hormone (ACTH) secretion is responsible for 5–15% of Cushing’s syndrome (CS). Neuroendocrine tumor (NET) is a common cause of ectopic ACTH syndrome (EAS). However, primary renal NET is exceedingly rare. Fewer than 100 cases have been reported and only a few cases presented with CS. Because of its rarity and lack of long-term follow-up data, clinical manifestations, biological behavior and prognosis are not well understood. Here, we report the case of a 51-year-old man who presented with clinical and laboratory findings compatible with EAS. CT scan revealed a lesion of uncertain nature at the lower pole of the left kidney. Octreotide scan found a filling defect at the lower pole of left kidney. It was difficult to determine if this finding was the true etiology or an incidental finding. Unfortunately, the patient’s clinical status rapidly deteriorated with limited medical treatment. The patient underwent left nephrectomy and left adrenalectomy. Histopathological examination confirmed NET with oncocytic features. Immunohistochemistry staining was positive for ACTH. The patient’s condition gradually improved. Additionally, glucocorticoid replacement was required only 6 months during a gradual recovery of hypothalamic pituitary adrenal axis achieved approximately three years after tumor removal. Although extremely rare, primary renal NET should be considered as a cause of EAS particularly in a patient with rapid clinical deterioration. Thorough investigation, early diagnosis and careful management are crucial to reduce morbidity and mortality.

Learning points

• Primary renal NET is an extremely rare cause of ectopic ACTH syndrome.

• Ectopic ACTH syndrome has a rapid onset with severe clinical manifestations. In this case, the patient’s condition deteriorated rapidly, resulting from severe hypercortisolism. Resection of the tumor is the most effective treatment.

• Localization of ectopic ACTH-secreting tumors is very challenging. Multimodality imaging including CT, MRI, octreotide scan, and positron emission tomography plays a crucial role in identifying the tumors. However, each imaging modality has limitations.

Summary

The etiology of hyponatremia is assessed based on urine osmolality and sodium. We herein describe a 35-year-old Asian man with pulmonary tuberculosis and perforated duodenal ulcer who presented with hyponatremia with hourly fluctuating urine osmolality ranging from 100 to 600 mosmol/kg, which resembled urine osmolality observed in typical polydipsia and SIADH simultaneously. Further review revealed correlation of body temperature and urine osmolality. Since fever is a known non-osmotic stimulus of ADH secretion, we theorized that hyponatremia in this patient was due to transient ADH secretion due to fever. In our case, empiric exogenous glucocorticoid suppressed transient non-osmotic ADH secretion and urine osmolality showed highly variable concentrations. Transient ADH secretion-related hyponatremia may be underrecognized due to occasional empiric glucocorticoid administration in patients with critical illnesses. Repeatedly monitoring of urine chemistries and interpretation of urine chemistries with careful review of non-osmotic stimuli of ADH including fever is crucial in recognition of this etiology.

Learning points:

• Hourly fluctuations in urine osmolality can be observed in patients with fever, which is a non-osmotic stimulant of ADH secretion.

• Repeated monitoring of urine chemistries aids in the diagnosis of the etiology underlying hyponatremia, including fever, in patients with transient ADH secretion.

• Glucocorticoid administration suppresses ADH secretion and improves hyponatremia even in the absence of adrenal insufficiency; the etiology of hyponatremia should be determined carefully in these patients.

Summary

Multiple endocrine metastases are a rare but possible complication of lung adenocarcinoma (LAC). Pituitary metastasis is a rare condition with poor clinical expression. Diabetes insipidus (DI) is its most common presenting symptom. Here we report an original case of a pituitary stalk (PS) metastasis from LAC presenting as central DI followed by adrenal insufficiency (AI) from bilateral adrenal metastasis, without known evidence of the primary malignancy. A 45-year-old woman whose first clinical manifestations were polyuria and polydipsia was admitted. She was completely asymptomatic with no cough, no weight loss or anorexia. Chest radiography was normal. Brain MRI showed a thick pituitary stalk (PS). DI was confirmed by water restriction test and treated with vasopressin with great clinical results. Explorations for systemic and infectious disease were negative. Few months later, an acute AI led to discovering bilateral adrenal mass on abdominal CT. A suspicious 2.3 cm apical lung nodule was found later. Histopathological adrenal biopsy revealed an LAC. The patient received systemic chemotherapy with hormonal replacement for endocrinological failures by both vasopressin and hydrocortisone. We present this rare case of metastatic PS thickness arising from LAC associated with bilateral adrenal metastasis. Screening of patients with DI and stalk thickness for lung and breast cancer must be considered. Multiple endocrine failures as a diagnostic motive of LAC is a rare but possible circumstance.

Learning points:

• Adrenal metastasis is a common location in lung adenocarcinoma; however, metastatic involvement of the pituitary stalk remains a rare occurrence, especially as a leading presentation to diagnose lung cancer.

• The posterior pituitary and the infundibulum are the preferential sites for metastases, as they receive direct arterial blood supply from hypophyseal arteries.

• Patients diagnosed with diabetes insipidus due to pituitary stalk thickness should be considered as a metastasis, after exclusion of the classical systemic and infectious diseases.

• The diagnosis of an endocrinological metastatic primary lung adenocarcinoma for patients without respiratory symptoms is often delayed due to a lack of correlation between endocrinological symptoms and lung cancer.

• The main originality of our case is the concomitant diagnosis of both endocrinological failures, as it was initiated with a diabetes insipidus and followed by an acute adrenal insufficiency.

Summary

We report our experience on managing a case of florid Cushing’s disease with Methicillin-resistant Staphylococcus aureus (MRSA) sepsis using intravenous etomidate in the intensive care unit of a UK district general hospital.

Learning points:

• Severe Cushing’s syndrome is associated with high morbidity and mortality.

• Etomidate is a safe and effective medical therapy to rapidly lower cortisol levels even in the context of severe sepsis and immunosuppression.

• Etomidate should ideally be administered in an intensive care unit but is still feasible in a district general hospital.

• During treatment with etomidate, accumulation of serum 11β-deoxycortisol (11DOC) levels can cross-react with laboratory cortisol measurement leading to falsely elevated serum cortisol levels. For this reason, serum cortisol measurement using a mass spectrometry assay should ideally be used to guide etomidate prescription.

Learning points:

• In a young patient with concurrent hypokalemia and uncontrolled hypertension on multiple antihypertensive agents, secondary causes of hypertension should be evaluated.

• Patients with Cushing’s syndrome can develop an acquired hypercoagulable state leading to spontaneous and postoperative venous thromboembolism.

• Pulmonary emboli may complicate the imaging of the bronchial carcinoid tumor in ectopic ACTH syndrome.

• Imaging with Gallium-68 DOTATATE PET/CT scan has the highest sensitivity and specificity in detecting ectopic ACTH-secreting tumors.

• A combination of various noninvasive biochemical tests can enhance the diagnostic accuracy in differentiating Cushing’s disease from ectopic ACTH syndrome provided they have concordant results. Bilateral inferior petrosal sinus sampling remains the gold standard.

Learning points:

• Sheehan’s syndrome can occur, though rarely, without an obvious major post-partum hemorrhage.

• The syndrome may resemble lymphocytic hypophysitis clinically and imaging studies may be crucial in order to differentiate both conditions.

• Hypopituitarism presentation may be variable and depends on the specific hormone deficit.

• Euvolemic hyponatremia workup must include thyroid function test and 08:00 AM cortisol levels.