A 50-year-old man presented to the hospital with a 3-week history of excessive thirst, urinary frequency, and right loin pain. He had felt generally unwell for the previous 8 weeks and had lost approximately 6 kg of weight over this time. He felt nauseous and had vomited several times. He urinated 4-5 times at night and had recorded a urine output of 3 L in 24 h at home. He had dull, right loin pain that did not radiate, was constant in nature, but exacerbated by movement. His appetite was grossly reduced. He was an ex-smoker [30 pack years].
On clinical examination, he was afebrile and normotensive. His heart rate was 70 beats per minute and regular.
Results on admission were as follows: plasma osmolality of 289 mosmol/kg, urine osmolality (random) of 396 mosmol/kg, and urine sodium of 23 mmol/L. He was admitted into the hospital, and during hospital stay, he underwent an endocrine profile, with results shown in Table 1.
His results were consistent with panhypopituitarism. He was commenced on hydrocortisone and subsequently felt much better. The nausea and vomiting stopped, and his 24-h urine output remained at 3 L.
He presented again to the emergency department 4 days after discharge with worsening nausea and vomiting. He was unable to eat and could not tolerate his prescribed medications. He was given fluids, hydrocortisone, and antiemetic intravenously. Within 48 h, he felt well and was able to eat and drink normally; therefore, IV fluids were stopped. The dose of hydrocortisone was doubled for another 48 h and given orally. Levothyroxine and testosterone were also started.
With further history assessment, he reported being unwell for more than a year, with excessive lethargy. He had decreased libido and was unable to maintain an erection.
Examination revealed cervical lymphadenopathy that had not been present or recorded on previous examination. An in-patient MRI of the head was performed and showed "multiple ring enhancing lesions [>50], including a lesion in relation to the pituitary stalk measuring 8 mm. There was no associated mass effect or significant edema" (Figure 5).
Chest X-ray imaging was performed and showed a left hilar mass. Urgent CT of the chest, abdomen, and pelvis was then arranged, which showed a large left upper lobe mass consistent with bronchogenic carcinoma. Lung, nodal, hepatic, and adrenal metastases were identified [CT staging tbl4, N3, M1]. Lymph node biopsy of a left cervical node was performed under ultrasound guidance. Histology confirmed a diagnosis of small cell carcinoma of the lung.
He was commenced on dexamethasone (hydrocortisone was stopped) along with thyroid hormone and testosterone, but he died 2 weeks later.