Endocrine Abstracts

Introduction: POEMS syndrome is a rare multisystem disorder characterized by polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma-proliferative disorder and skin changes. Different endocrinopathies are found in 58-80% of patients, however, its pathophysiology remains unknown. Hypogonadism (primary and secondary) is the most common endocrinopathy (79% of patients), with other abnormalities including hyperprolactinemia (56%), primary hypothyroidism (54%), abnormal glucose metabolism (24%), primary adrenal insufficiency (17%), and elevated IGF-1 levels (14.8%). We present two cases of endocrinopathy in POEMS syndrome.

Clinical Cases: Patient 1, 59-year-old female, and Patient 2, 52-year-old male, diagnosed with POEMS Syndrome, initiated follow-up in our clinic due to the potential risk of associated endocrinopathies. Patient 1 presented fatigue and cutaneous hyperpigmentation. The initial assessment revealed primary hypothyroidism and suspicion of primary adrenal insufficiency - TSH 15.6 µU/ml (RR:0.30-4.20), FT4 0.74 ng/dl (RR:0.85-1.70); ACTH 66.3 pg/ml (RR:0-46), cortisol 6.3 µg/dl (RR:4-23), confirmed by the Synacthen® test with a cortisol peak of 10.6 mg/dl at 30 min. Treatment with hydrocortisone followed by levothyroxine was initiated. Five years after, in the period post-menopause, asymptomatic hyperprolactinemia and hypogonadotropic hypogonadism (HH) were observed - prolactin 131.4 ng/ml (RR:4.7-23.0), FSH 5.3 U/l (RR:25.0-134.9), LH 2.43 U/l (RR:7.7-58.5). The pituitary MRI showed an empty sella turcica. Patient 2 had decreased libido, fatigue, and muscle weakness. The initial endocrine evaluation revealed HH and subclinical hypothyroidism – FSH 2.8 U/l (RR:1.5-12.9), LH 1.8 U/l (RR:1.3-9.8), total testosterone 55.7 ng/dl (RR:190-740); TSH 13.8 µU/ml, FT4 1.03 ng/dl. It was also suggestive of primary adrenal insufficiency - ACTH 164 pg/ml, cortisol 9.6 µg/dl, later confirmed by the Synacthen® test – cortisol peak 10.6 mg/dl at 60 min. Hydrocortisone treatment was initiated but testosterone replacement therapy was not due to the associated thrombotic risk.

Discussion: Both patients presented HH, the most common endocrinopathy in POEMS Syndrome. The association between hypothyroidism and POEMS Syndrome remains unclear, considering its prevalence in the general population. Although rare, primary adrenal insufficiency was observed in both cases. The literature suggests a potential association between POEMS Syndrome and an empty sella turcica, as seen in Patient 1. Despite this evidence, the only pituitary deficit identified in this patient was HH, without any relation with hypothyroidism and adrenal insufficiency.

Conclusions: Unrecognized endocrinopathy poses a significant risk for morbidity in POEMS syndrome. A multidisciplinary approach is crucial for systematic endocrine assessment in these patients to enhance early detection and management.