1 Introduction

McCune-Albright syndrome (MAS) is characterized by multiple endocrine abnormalities, polyostotic fibrous dysplasia, pigmented skin lesions, and/or precocious puberty. Prevalence estimates range from 1/1,00,000 to 1/10,00,000.¹ Gs alpha mutations, which is the cAMP regulating protein, encoded by the GNAS gene, is responsible for the disease.² This leads to formation of scar-like fibrous tissue. It maybe monostotic (affecting single bone) or polyostotic (affecting multiple bones). Common sites include long bones, pelvis, and facial bones. Clinically, bony involvement is predominant on one side and may manifest with pathological fractures, aberrant gait, bone discomfort, and deformities. Multiple operations and comprehensive deformity correction techniques may be necessary to treat progressive limb abnormalities and pathological fractures. Mutations arise spontaneously during embryonic development and the severity of illness depends on the proliferation, migration, and survival of the mutated cell. 4% patients have been documented to have high-grade sarcomas, despite the rarity of malignant change.³ Diagnosis is mainly clinical.

Here we describe a case of an active 15-year-old boy who had been experiencing hip discomfort for a while before being diagnosed with MAS and needing prophylactic fixation to reduce the likelihood of pathological hip fractures.

2 Case report

Parents of an active 15-year-old boy brought him with chief complaints of left hip and thigh pain for the past 3 years. The patient had no history of severe trauma. Initial treatment included physiotherapy and medication which provided no relief. Over the past three years, the moderately intense, dull aching pain progressively spread to his left leg which was relieved with rest and aggravated by activity. On total body examination, the patient had irregularly shaped 12 ​× ​4 cm café-au-lait spots on his left torso. (Fig. 1). His parents described a history of pubic and axillary hair appearing by the age of eight and a rapid growth spurt by the age of twelve. The patient had no history of any prior surgical procedures.

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Fig. 1 Pigmented skin lesions (café-au-lait spots) over left torso.

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Sclerotic lesion visualised in the neck and proximal part of the femur on anteroposterior and lateral radiographs of the left hip (Fig. 2). Magnetic Resonance Imaging (MRI) of the Left Hip and femur showed a hyperintense heterogenous area in the left femoral neck extending into the proximal shaft (Fig. 3). Bone Scanning was done to rule other sites of involvement. It showed multiple osteoblastic lesions in the head, proximal and distal part of left femur, proximal epiphysis and diaphysis of left tibia (Fig. 4). Haematological investigations were done to rule out endocrinopathies. The patient was found to have a deranged thyroid profile. His T3, T4 levels were high and thyroid stimulating hormone (TSH) were low. The presence of hyperthyroidism, café-au-lait pigmentation, and polyostotic fibrous dysplasia together with premature puberty reinforced the McCune Albright Syndrome diagnosis.

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Fig. 2 Pre-operative radiographs showing areas of sclerosis in the neck and left proximal femur.

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Fig. 3 Magnetic Resonance Imaging (MRI) of the Left Hip and femur – T2 weighted image showed a hyperintense heterogenous area in the left femoral neck extending into the proximal shaft (blue arrow). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)

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Fig. 4 Bone scan showing osteoblastic lesions in the head, proximal and distal part of left femur, proximal epiphysis and diaphysis of left tibia.

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After carefully examining the patient's medical history and imaging results, preventive intramedullary proximal femur nailing with curettage was advised as a surgical intervention for pain relief and to avoid further pathological fractures and bone abnormalities. Appropriate pharmacological therapy was started to make the patient euthyroid prior to surgery.

The patient was placed supine on the fracture table. Greater trochanter (GT) was localized and a 5 cm incision was taken, 5 cm proximal to the tip of the trochanter, extending along the axis of the femoral shaft. Blunt dissection of the gluteus maximus done and entry point localized. Entry made just lateral to the tip of the GT and guidewire inserted. First reaming done using a small-sized reamer. Through the entry point, circumferential local curettage of the proximal femur medullary canal was performed. Reamers of increasing sizes were used for the final reaming till contact with the cortices was obtained. Intramedullary tissue sample was taken for histological evaluation. A thorough wash given, and an intramedullary proximal femoral nail is used for fixation. Histopathological analysis showed findings consistent with fibrous dysplasia with no evidence of malignancy (Fig. 5). Immediate Postoperative radiographs were obtained (Fig. 6).

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Fig. 5 Histopatholocgical section shows fibrous tissue with immature woven bone. The fibrous tissue is low cellularity with bland fibroblasts in spindle cell appearance arranged in fascicular pattern.

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Fig. 6 Immediate Post – operative radiographs.

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The wound examination and suture removal were successful following surgery. Full weight bearing was permitted for the patient right after the operation. The patient's subsequent follow-up went without incident. Follow-up radiographs at three years revealed no signs of a fracture, deformity, or tumor growth (Fig. 7). He has been under follow-up for three years with positive clinical results, no recurrence signals, and no restrictions on his ability to lead a normal personal and professional life.

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Fig. 7 3-year follow-up radiographs showing no evidence of fracture, deformity or tumor progression.

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An extensive PubMed search (http://www.ncbi.nlm.nih.gov/pubmed) using the following combinations of keywords: “McCune Albright Syndrome”; or “MAS”; or “McCune Albright Syndrome Surgery” and “McCune Albright Syndrome Nailing”. Only English-language publications were included in the search with no date limitations (Table 1).

3 Discussion

Café-au-lait skin pigmentation, precocious puberty (PP) and polyostotic fibrous dysplasia were originally described as the triad of McCune-Albright Syndrome (MAS).^4,5 Further understanding of the syndrome showed that other endocrine disorders may also be associated with it. These include renal phosphate wasting with or without rickets/osteomalacia,⁶ increased levels of the growth hormone,⁷ or increased thyroid hormone levels.⁸ Original triad can also be found in association with Cushing syndrome.⁹ Liver, heart, parathyroid and pancreas are rarely involved.¹⁰ Fibrous Dysplasia can be monostotic (affecting single bone, MFD) or polyostotic (affecting multiple bones, PFD).¹¹ FD associated with MAS is of polyostotic variety. In general, the most common association of MAS is PFD. But very rarely, in about 1% cases, PFD can be absent from the triad of MAS. This renders the older definitions of MAS incomplete. Thus, a more complete and clinically relevant definition of MAS may include PFD with any one hyperfunctioning endocrine disorder and/or café-au-lait spots.¹² Fibrous dysplasia is a developmental defect primarily affecting osteoblasts. The affected osteoblasts are unable to differentiate properly and cause bone maturation defects.¹³ The accumulation of scar-like fibrous tissue in the bones causes tumor-like lesions in the bones. Patients become symptomatic typically during late adolescence or early adulthood. Treating such lesions is always difficult and no standard guidelines are available for treatment. Patients may present with persistent bone pains, fractures resulting as a result of trivial trauma, pathological fractures or progressive deformities. Chances of recurrence post treatment are high as well.¹⁴ Deformities involving the proximal femur (Shepherd crook deformity, Coxa Vara) are commonly seen. Patients with MAS might have a history of multiple surgeries with extensive internal fixation devices in-situ. The treatment modalities differ from case to case and surgeons usually follow an individualized approach.

In this case, the focus was on pain relief, deformity, and pathological fracture prevention. So, curettage and prophylactic fixation with a long proximal femoral nail was planned for the patient. Curettage of the lesion helps to decompress the proximal femur to achieve pain relief and prophylactic fixation helps prevent deformity and pathological fractures as well as the need for future deformity correction procedures.

4 Limitations

Due to the rarity of MAS, there is a lack of data and evidence demonstrating that preventive intramedullary nailing is a successful therapy strategy in all MAS patients. Large-scale multicentric studies are therefore necessary to provide precise management criteria. Recent research indicates that denosumab may be a successful alternative to surgery, however further research on the safety and discontinuation of denosumab is still being conducted.²⁰

5 Conclusion

In conclusion, MAS and FD can manifest in adolescents with a wide range of symptoms, the most prevalent of which is chronic pain. Therefore, it is crucial to keep MAS/FD in mind when evaluating such individuals. This aids in early diagnosis and treatment. Prophylactic fixation effectively relieves pain, prevents deformity, and lowers the risk of pathological fractures. An intramedullary device or a Dynamic hip screw can be used. The advantages of an intramedullary device over a Dynamic hip screw are a smaller incision, lower dissection, a more secure intramedullary construct, earlier mobility, and weight bearing. Consequently, preventive intramedullary fixation is a fantastic therapeutic technique for MAS/FD.

Funding

No funding in any form has been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.

Author's contribution

All the authors were involved in acquisition, analysis, interpretation and in drafting the manuscript. All authors read and approved the final manuscript.

Institutional ethics committee approval

The protocol was approved by the Medical Ethics Committee.

Parent consent

Consent for publication of radiographic and clinical photos was obtained from the parents.