Postpartum Granulomatous Hypophysitis: A Case Study, Review of the Literature, and Discussion of Pathogenesis

Biochemical transition during triphasic postpartum thyroiditis: confusion with central hypothyroidism

Summary

Hypothyroidism occurring in the postpartum period can be due to pituitary or hypothalamic disease as in Sheehan’s syndrome and postpartum autoimmune hypophysitis or due to a primary thyroid disease as in postpartum thyroiditis. It is important that the correct diagnosis is ascertained because hypothalamic or pituitary disorders are often associated with other pituitary hormone deficiencies, especially life-threatening adrenal insufficiency or adrenal crisis. A combination of various symptoms and biochemical markers, especially serum thyroid-stimulating hormone levels dictate the initial diagnostic pathway. We present a case of a woman who presented with a 2-month history of tiredness and neck discomfort following delivery. A thyroid function test demonstrated results, which we initially interpreted as central hypothyroidism. Follow-up results indicated that this was in fact the transition period between the thyrotoxic phase and hypothyroid phases of postpartum thyroiditis. This case highlights the potential for diagnostic confusion between central hypothyroidism and postpartum thyroiditis.

Learning points

Pregnancy-associated diabetes insipidus in Japan-a review based on quoting from the literatures reported during the period from 1982 to 2019

This Review Article overviews the literature on diabetes insipidus (DI) associated with pregnancy and labor in Japan published from 1982 to 2019. The total number of patients collected was 361, however, only one-third of these cases had detailed pathophysiologic information enabling us to identify the respective etiology and subtype. Pregnancy-associated DI can be divided into 3 etiologies, central (neurogenic) DI, nephrogenic DI, and excess vasopressinase-associated DI. Neurogenic DI has various causes: for example, DI associated with tumoral lesions in the pituitary and neighboring area, DI associated with Sheehan's syndrome and/or pituitary apoplexy, and DI associated with lymphocytic infundibuloneurohypophysitis (LINH, stalkitis). Nephrogenic DI results from defective response of the kidney to normal levels of vasopressin. However, the most interesting causal factor of pregnancy-associated DI is excess vasopressinase, caused either by excess production of vasopressinase by the placenta or defective clearance of vasopressinase by the liver. Hepatic complications resulting in pregnancy-associated DI include acute fatty liver of pregnancy (AFLP) and HELLP syndrome (syndrome of hemolysis, elevated liver enzymes, low platelets), as well as pre-existing or co-incidental hepatic diseases. A possible role of glucose uptake in putative stress-induced DI and the importance of correct diagnosis and treatment of pregnancy-associated DI, including use of 1-deamino 8-D arginine vasopressin, are also discussed.