Diagnosis and Treatment > Signs and Symptoms
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Summary
A male patient presented at the age of 30 with classic clinical features of acromegaly and was found to have elevated growth hormone levels, not suppressing during an oral glucose tolerance test. His acromegaly was originally considered to be of pituitary origin, based on a CT scan, which was interpreted as showing a pituitary macroadenoma. Despite two trans-sphenoidal surgeries, cranial radiotherapy and periods of treatment with bromocriptine and octreotide, his acromegaly remained active clinically and biochemically. A lung mass was discovered incidentally on a chest X-ray performed as part of a routine pre-assessment for spinal surgery 5 years following the initial presentation. This was confirmed to be a bronchial carcinoid tumour, which was strongly positive for growth hormone-releasing hormone (GHRH) and somatostatin receptor type 2 by immunohistochemistry. The re-examination of the pituitary specimens asserted the diagnosis of pituitary GH hyperplasia. Complete resolution of the patient’s acromegaly was achieved following right lower and middle lobectomy. Seventeen years following the successful resection of the bronchial carcinoid tumour the patient remains under annual endocrine follow-up for monitoring of the hypopituitarism he developed after the original interventions to his pituitary gland, while there has been no evidence of active acromegaly or recurrence of the carcinoid tumour. Ectopic acromegaly is extremely rare, accounting for <1% of all cases of acromegaly. Our case highlights the diagnostic challenges differentiating between ectopic acromegaly and acromegaly of pituitary origin and emphasises the importance of avoiding unnecessary pituitary surgery and radiotherapy. The role of laboratory investigations, imaging and histology as diagnostic tools is discussed.
Learning points:
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Ectopic acromegaly is rare, accounting for less than 1% of all cases of acromegaly.
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Ectopic acromegaly is almost always due to extra-pituitary GHRH secretion, mainly from neuroendocrine tumours of pancreatic or bronchial origin.
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Differentiating between acromegaly of pituitary origin and ectopic acromegaly can cause diagnostic challenges due to similarities in clinical presentation and biochemistry.
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Serum GHRH can be a useful diagnostic tool to diagnose ectopic acromegaly.
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Pituitary imaging is crucial to differentiate between a pituitary adenoma and pituitary hyperplasia, which is a common finding in ectopic acromegaly.
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Diagnosing ectopic acromegaly is pivotal to avoid unnecessary interventions to the pituitary and preserve normal pituitary function.
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Summary
We present a case of a young female patient with a rare cause of relapsing and remitting Cushing’s syndrome due to ectopic ACTH secretion from a thymic neuroendocrine tumour. A 34-year-old female presented with a constellation of symptoms of Cushing’s syndrome, including facial swelling, muscle weakness and cognitive impairment. We use the terms ‘relapsing and remitting’ in this case report, given the unpredictable time course of symptoms, which led to a delay of 2 years before the correct diagnosis of hypercortisolaemia. Diagnostic workup confirmed ectopic ACTH secretion, and a thymic mass was seen on mediastinal imaging. The patient subsequently underwent thymectomy with complete resolution of her symptoms. Several case series have documented the association of Cushing’s syndrome with thymic neuroendocrine tumours (NETs), although to our knowledge there are a few published cases of patients with relapsing and remitting symptoms. This case is also notable for the absence of features of the MEN-1 syndrome, along with the female gender of our patient and her history of non-smoking.
Learning points
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Ectopic corticotrophin (ACTH) secretion should always be considered in the diagnostic workup of young patients with Cushing’s syndrome
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There is a small but growing body of literature describing the correlation between ectopic ACTH secretion and thymic neuroendocrine tumours (NETs)
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The possibility of a MEN-1 syndrome should be considered in all patients with thymic NETs, and we note the observational association with male gender and cigarette smoking in this cohort
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An exception to these associations is the finding of relatively high incidence of thymic NETs among female non-smoking MEN-1 patients in the Japanese compared with Western populations
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The relapsing and remitting course of our patient’s symptoms is noteworthy, given the paucity of this finding among other published cases
Department of Medicine, Division of Endocrinology and Metabolism, Taipei Veterans General Hospital, Taipei, Taiwan
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Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
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Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
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Department of Otorhinolaryngology-Head and Neck Surgery, Division of Otology, Taipei Veterans General Hospital, Taipei, Taiwan
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Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
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Summary
A functional lesion in corticotrophin (ACTH)-independent Cushing’s syndrome is difficult to distinguish from lesions of bilateral adrenal masses. Methods for distinguishing these lesions include adrenal venous sampling and 131I-6β-iodomethyl-19-norcholesterol (131I-NP-59) scintigraphy. We present a case of a 29-year-old Han Chinese female patient with a history of hypercholesterolaemia and polycystic ovary syndrome. She presented with a 6month history of an 8kg body weight gain and gradual rounding of the face. Serial examinations revealed loss of circadian rhythm of cortisol, elevated urinary free-cortisol level and undetectable ACTH level (<5pg/mL). No suppression was observed in both the low- and high-dose dexamethasone suppression tests. Adrenal computed tomography revealed bilateral adrenal masses. Adrenal venous sampling was performed, and the right-to-left lateralisation ratio was 14.29. The finding from adrenal scintigraphy with NP-59 was consistent with right adrenal adenoma. The patient underwent laparoscopic right adrenalectomy, and the pathology report showed adrenocortical adenoma. Her postoperative cortisol level was 3.2μg/dL, and her Cushingoid appearance improved. In sum, both adrenal venous sampling and 131I-NP-59 scintigraphy are good diagnostic methods for Cushing’s syndrome presenting with bilateral adrenal masses.
Learning points
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The clinical presentation of Cushing’ syndrome includes symptoms and signs of fat redistribution and protein-wasting features.
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The diagnosis of patients with ACTH-independent Cushing’s syndrome with bilateral adrenal masses is challenging for localisation of the lesion.
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Both adrenal venous sampling and 131I-NP-59 scintigraphy are good methods to use in these patients with Cushing’s syndrome presenting with bilateral adrenal masses.
