Differential Diagnosis
- Single most likely diagnosis
- B. Lymphocytic hypophysitis: This condition is an autoimmune inflammation of the pituitary gland, which can occur postpartum. The patient's symptoms of headache, profound weakness, and nausea/vomiting, along with the presence of a sellar mass on MRI, are consistent with this diagnosis. The elevated serum prolactin and low serum cortisol also support this diagnosis, as lymphocytic hypophysitis can cause hypopituitarism.
- Other Likely diagnoses
- E. Sheehan syndrome: This is a condition caused by necrosis of the pituitary gland, usually occurring postpartum due to hemorrhage or infarction. The patient's symptoms and laboratory results, including low serum cortisol and sodium, could be consistent with Sheehan syndrome. However, the presence of a sellar mass on MRI is more suggestive of lymphocytic hypophysitis.
- D. Prolactinoma: Although the serum prolactin is elevated, the patient's symptoms and the presence of a sellar mass could be consistent with a prolactinoma. However, the low serum cortisol and sodium levels are not typical of a prolactinoma.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- A. Addison’s disease: Although less likely, Addison's disease is a life-threatening condition that requires prompt diagnosis and treatment. The patient's low serum cortisol and sodium levels could be consistent with Addison's disease, but the presence of a sellar mass and elevated prolactin make lymphocytic hypophysitis more likely.
- Rare diagnoses
- C. Non-functioning pituitary tumor: This is a less likely diagnosis, as non-functioning pituitary tumors typically do not cause hypopituitarism or the patient's symptoms. However, it is possible that a non-functioning tumor could cause mass effect and lead to hypopituitarism.