Differential Diagnosis of Acromegaly: Pachydermoperiostosis Two New Cases from Turkey

Abstract

Pachydermoperiostosis (PDP), also known as primary hypertrophic osteoarthropathy, is a rare genetic disorder characterized by pachyderma and periostosis. Acromegaly is a condition caused by excessive secretion of growth hormone (GH) leading to elevated insulin-like growth factor 1 levels, and is characterised by somatic overgrowth and physical disfigurement, notably affecting hands and feet. We present two cases referred with an initial diagnosis of acromegaly that were ultimately diagnosed as PDP. Case 1: A 17 year-old boy presented with enlargement in both feet and hands, finger clubbing, swelling in knee joints, knee pain, coarsening of facial skin lines and forehead skin, and excessive sweating which increased gradually over five years. There were prominent skin folds on the forehead, face, and eyelids. Also, there was an enlargement in both hands and clubbing of the fingers. There was marked swelling in the knee joints and ankles. Genetic analysis revealed a novel homozygous variant NM_005630: c.31C>T (p.Q11*) in the SLCO2A1 gene. Case 2: A 16 year-old boy presented with coarsening of forehead skin and scalp, excessive sweating, and pain in the elbow and knee over three years. Skin folds were prominent on the forehead and scalp. Genetic analysis revealed a homozygous variant NM_005630.2:c.86delG (p.G29Afs*48) in the SLCO2A1 gene. Such clinical presentation contemporaneous with normal GH level and prominent radiological abnormalities prompted the diagnosis of PDP. In conclusion, PDP is a very rare osteoarthrodermopathic disorder with clinical and radiographic presentation that may mimic acromegaly. In the evaluation of patients with acromegaloid appearance, PDP should be considered as a differential diagnosis.

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

“…Moreover, the coexistence of tall stature/overgrowth with acromegaloid physical features seem to be more prevalent in insulin‐mediated pseudoacromegaly than in other pseudoacromegaly conditions, which may further explain the increased referrals of such cases to paediatric/adult endocrinologists for the evaluation of excessive growth. In contrast, pachydermoperiostosis cases were mainly referred to non‐endocrine specialists, including dermatologists and internists, given the prominent skin and skeletal manifestations typical of this condition 11,38–42 ; however, many reported pachydermoperiostosis patients were first referred and diagnosed by endocrinologists 5,23,43–50 . Endocrinologists should be familiar with these conditions and always consider them in the work‐up of a pseudoacromegaly case.…”

“…In contrast, pachydermoperiostosis cases were mainly referred to non-endocrine specialists, including dermatologists and internists, given the prominent skin and skeletal manifestations typical of this condition 11,[38][39][40][41][42] ; however, many reported pachydermoperiostosis patients were first referred and diagnosed by endocrinologists. 5,23,[43][44][45][46][47][48][49][50] Endocrinologists should be familiar with these conditions and always consider them in the work-up of a pseudoacromegaly case. Besides the GH/ IGF-1 axis assessment to rule out acromegaly, the investigation should include thyroid function tests, glucose, insulin, HbA1c and lipid profile.…”

A Complete Form of Pachydermoperiostosis Accompanied by a Pituitary Microadenoma

“…Digital clubbing and periostosis are not seen in acromegaly. 11 , 15 Endocrine testing and pituitary MRI examination are important to confirm the diagnosis of acromegaly. Measurement of serum IGF-1 to rule out acromegaly has been recommended in any patients harbouring a pituitary adenoma, and a normal serum IGF-1 concentration is strong evidence that the patient does not have acromegaly.…”

“… 11 , 16 Both serum GH concentrations and IGF-1 concentrations are increased in virtually all patients with acromegaly. 15 TA is a rare extrathyroid manifestation of autoimmune thyroid disease (AITD), which manifests as soft tissue swelling with digital clubbing and always associated with thyroid ophthalmopathy and dermopathy. For the chronological sequence of extrathyroidal manifestations of AITD, thyroid dysfunction develops first, followed by ophthalmopathy, dermopathy, and finally, acropachy.…”

“…11,16 Both serum GH concentrations and IGF-1 concentrations are increased in virtually all patients with acromegaly. 15 TA is a rare extrathyroid manifestation of autoimmune thyroid disease (AITD), which manifests as soft…”