Pachydermoperiostosis Masquerading as Acromegaly

CONTEXT: Acromegaly usually is suspected on clinical grounds. Biochemical confirmation is required to optimize therapy, but there are other differential diagnoses. CASE DESCRIPTION: We describe a 24-year-old Uzbek man who presented with many clinical symptoms and signs of apparent acromegaly. On examination, the patient showed a rugose folding of his scalp, with the formation of tender, painful, rough skin folds in the parietal-occipital region, resembling cerebral gyri (i.e., cutis verticis gyrate). There was also a thickening and enlargement of the eyelids due to cartilaginous hypertrophy, dystrophic changes of the conjunctiva, and atrophy of the Meibomian glands, with the formation of multiple cysts and granulomas. He perspired excessively. There was thickening of the facial skin, with increased oiliness, increased rugosity, and seborrheic dermatitis. The skin over the hands was thick and apparently fixed to the underlying tissues. However, the patient had a low-normal insulin-like growth factor-1 level. More detailed analysis revealed a family history of relatives with similar problems, and certain features were not in keeping with this diagnosis. The disorder pachydermoperiostosis, or pulmonary hypertrophic osteoarthropathy, was suspected, and next-generation screening confirmed that the patient was homozygous for a pathogenic mutation in the SLCO2A1 gene, c.764G>A (p.Gly255Glu). CONCLUSION: The condition of pachydermoperiostosis may masquerade as acromegaly but is a genetic disorder, usually autosomal recessive, leading to elevated prostaglandin E2 levels. This is an important, albeit rare, differential diagnosis of acromegaly.