Systemic Diseases with Endocrine Manifestations

• Endocrine manifestations of non-endocrine diseases (such as bronchogenic carcinoma with inappropriate antidiuretic hormone (ADH) secretion) : Non-endocrine diseases can give rise to important endocrine manifestations, often through paraneoplastic or systemic mechanisms.

Non-endocrine diseases—particularly malignancies and some systemic inflammatory or infectious conditions—can give rise to endocrine symptoms by abnormally producing hormones or hormone-like substances. These are known as paraneoplastic endocrine syndromes, and they occur independently of direct tumour invasion or metastasis.

In paraneoplastic processes, non-endocrine tumours begin to produce hormones or mimic hormone activity, disrupting normal endocrine regulation. This ectopic hormone secretion can lead to significant metabolic and clinical consequences.

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• The RCGP curriculum highlights the need for clinicians to recognise these atypical presentations, such as inappropriate antidiuretic hormone (ADH) secretion secondary to bronchogenic carcinoma, which may lead to hyponatraemia. These syndromes may be the first clue to an underlying malignancy or chronic condition. In the primary care setting, early identification of such features is essential for timely referral, appropriate investigation, and improved outcomes.

Condensed Table: Endocrine Manifestations of Non-Endocrine Diseases