Diagnosis of a Rare Endocrine Disorder – A Pain Physician’s Experience
Year: 2023
Type: article
Study design: Case Report
Abstract: Sir, McCune–Albright syndrome (MAS) is a rare sporadic disease resulting from early-onset postzygotic somatic mutations in the GNAS1 gene and is characterized by fibrous dysplasia (FD), café au lait spots, and various endocrine organs involvement.[1] The prevalence of MAS is estimated between 1/100,000 and 1/1,000,000.[2,3] MAS is generally diagnosed based on clinical findings. Although the importance of genetic testing in a clear clinical diagnosis is uncertain, it can be done if it is available. Histological examination is only required in questionable cases. If uncertain histologic findings are noted, confirmation by molecular tests is recommended.[4] We had a 34-year-old female referred to us from the orthopedic department for the complaint of radicular pain in her left leg for the past 6 months. She had a trivial fall from the stairs and sustained pathological fracture on her left lower extremity 2 years back for which open fixation with compression plate was done. Intraoperatively, tachycardia was detected, for which she was investigated postoperatively and diagnosed to have hyperthyroidism. She was started on medications, propylthiouracil and propranolol. One and half years later, she developed pain in the same leg but it mimicked a radicular pain and hence she was referred to us. On detailed history taking, she revealed that she had a precocious puberty, with full development of secondary sexual characteristics by 9 years of age. On clinical examination, there was swelling and tenderness in the right midshaft of the femur and café-au-lait pigmentation on the back [Figure 1]. Computed tomography (CT) lower extremity revealed FD of the femur bone. Following this, whole-body positron emission tomography CT showed the presence of polyostotic FD involving the upper and lower limbs, thorax, and skull [Figure 2]. The coexistence of precocious puberty with polyostotic FD, therefore, made the diagnosis of MAS. Once the diagnosis was made, she was started on bisphosphonates and alendronate combined with calcium and Vitamin D. This resulted in an improvement of bone pain.Figure 1: Clinical examination revealed café au lait spots in the lower back region of the patientFigure 2: Whole-body positron emission tomography computed tomography showing polyostotic fibrous dysplasia involving the upper and lower limbs, thorax, and skullIn our patient, the pain which was thought to be a radicular pain was actually a bone pain due to FD. Hence, treatment with bisphosphonates caused a gradual reduction in the pain. Bisphosphonates are a class of drugs widely indicated to treat osteoporosis. They attach to osteoclasts where they disrupt intracellular enzymatic functions needed for bone resorption. The primary effect of bisphosphonate treatment observed in MAS patients is the improvement of bone pain due to the anti-osteoclastic action of the drug, with reduction of cytokines, and other pain-related substances released by the lesions. Furthermore, improvement of bone mineral density occurs due to inhibition of bone resorption.[5] The purpose of this case report is to emphasize the need for pain physicians to be aware of rare genetic disorders such as MAS, as they can present with atypical symptoms which can mimic common disorders and can lead to improper diagnosis and management. Treatment for MAS involves a multidisciplinary approach, and in this case, we worked closely with endocrinologists and orthopedic surgeons to manage her symptoms. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Source: Indian Journal of Pain
Institution: ESIC Hospital
Language: English
Subfield: Orthopedics and Sports Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4390453069