Pseudoacromegaly Associated with Non-Functioning Pituitary Adenoma

Abstract

Acromegaly is characterized by excess skin and soft tissue growth due to increased growth hormone (GH) levels. Patients with similar physical findings but without somatotroph axis abnormalities are considered to have pseudoacromegaly. The list of pseudoacromegaly differential diagnoses is long. It may be caused by several congenital and acquired conditions and diagnosis can be challenging due to its rarity and occasional overlapping of some of these conditions. The presence of a pituitary tumour in such cases may lead to a misdiagnosis of acromegaly, and thus, biochemical evaluation is key. Here, we present a case of pseudoacromegaly with an acromegaloid phenotype, normal IGF levels, a supressed GH response to an oral glucose tolerance test, moderate insulin resistance and non-functioning pituitary microadenoma.

Pseudoacromegaly—A challenging entity in the endocrine clinic: A systematic review

“…Moreover, these cases may present to different medical specialists with distinct degrees of awareness and experience for pseudoacromegaly conditions, which may lead to further diagnostic delays, in some cases longer than 30 years, 14,15,18,26 or in others the underlying disorder may never be identified. [27][28][29][30][31][32] Adult and paediatric endocrinologists may be referred with pseudoacromegaly patients, thus it is important to be aware of this entity and recognize the most common conditions, or at least those that more likely mimicking acromegaly (pachydermoperiostosis and insulin-mediated pseudoacromegaly). Forty cases (57%) were referred to endocrinologists, predominantly insulin-mediated pseudoacromegaly cases, which may be explained, at least in part, by the common occurrence of metabolic disorders such as obesity, diabetes or dyslipidemia, while other endocrine-related issues may also coexist, including amenorrhoea, polycystic ovaries or hirsutism.…”

“…Most pseudoacromegaly conditions are rare and heterogeneous with a wide phenotypic variability within the same disease, and they often have overlapping features with other disorders, which imposes diagnostic difficulties. Moreover, these cases may present to different medical specialists with distinct degrees of awareness and experience for pseudoacromegaly conditions, which may lead to further diagnostic delays, in some cases longer than 30 years, 14,15,18,26 or in others the underlying disorder may never be identified 27–32 …”

“…Most pituitary adenomas in the pseudoacromegaly setting have been detected in young patients (as early as 14 years old; mean age at diagnosis 25 years), population where incidentalomas are less common 64–66 . Pituitary incidentalomas seem common in pseudoacromegaly (more than in the general population 67,68 ), and typically correspond to small nonfunctioning adenomas without clinical significance 4,32,34,36,38,45,48,69 . Nevertheless, such pituitary incidentalomas require careful judgement to prevent inappropriate surgery 14 .…”

“…[64][65][66] Pituitary incidentalomas seem common in pseudoacromegaly (more than in the general population 67,68 ), and typically correspond to small nonfunctioning adenomas without clinical significance. 4,32,34,36,38,45,48,69 Nevertheless, such pituitary incidentalomas require careful judgement to prevent inappropriate surgery. 14 Pituitary hyperplasia was reported in a 57-year-old female with insulin-mediated pseudoacromegaly, 15 and in two males (ages 22 and 64) with pseudoacromegaly due to long-standing primary hypothyroidism in whom the hyperplasia resolved following euthyroidism restoration 16,17 ;…”