Primary Hypothyroidism Mimicking Spondyloepiphyseal Dysplasia

We report the case of a 20-year-old male adolescent who presented to the emergency department with a fever and altered mental status. Examination revealed signs of meningeal irritation, and cerebrospinal fluid analysis indicated a diagnosis of tubercular meningitis. The physical examination uncovered features suggestive of hypothyroidism, including marked short stature (height: 128 cm; z-score: –6.1), face puffiness, dry skin, and delayed ankle reflex relaxation. Sexual maturity assessment indicated pubic hair staging of P3 and a testicular volume of 20 mL bilaterally. The discordance between pubic hair staging and testicular volume suggested macro-orchidism [Figure 1]. According to the Greulich–Pyle method, the bone age was 6 years.Figure 1: Showing macro-orchidism with a testicular volume of 20 mL measured using a Prader orchidometerThyroid function tests confirmed primary hypothyroidism, with a total triiodothyronine level of 26 ng/dL (normal: 80–180 ng/dL), a total thyroxine level of 0.3 µg/dL (normal: 4.6–12.0 µg/dL), and a thyroid-stimulating hormone level of >100 µIU/mL (normal: 0.36–5.4 µIU/mL). Additional hormonal evaluation showed a luteinizing hormone level of 0.4 IU/L (reference: 1.2–8.6 IU/L), follicle-stimulating hormone level of 1.6 IU/L (reference: 1.2–19.2 IU/L), and total testosterone of 26.4 ng/dL (reference: 175–781 ng/dL). A skeletal survey showed irregular and fragmented proximal femoral epiphyses and flattened vertebrae with reduced height, indicative of spondyloepiphyseal dysplasia [Figures 2a and 3a]. After 6 months of levothyroxine treatment, follow-up imaging revealed resolution of epiphyseal stippling and improvement in vertebral body height [Figures 2b and 3b].Figure 2: Pretreatment image (a) shows irregular, fragmented proximal femoral epiphyses (black star) with stippling, sclerotic growth plates, and delayed fusion of the triradiate cartilage (black arrow). Post-treatment image (b) demonstrates resolution of stippling, improved epiphyseal contours, and signs of progression in skeletal maturation. However, the triradiate cartilage and greater trochanteric epiphyses (white star) remain unfusedThe skeletal changes observed in hypothyroidism closely resemble and may be mistaken for the skeletal abnormalities characteristic of epiphyseal dysplasias. Hypothyroidism should be considered in the differential diagnosis of spondyloepiphyseal dysplasia, particularly in regions where neonatal thyroid screening is not routinely performed. Timely initiation of thyroid hormone replacement results in significant improvement in epiphyseal morphology and vertebral height. Acknowledgment Nil. Author contributions All four authors were directly involved in patient care. AA and KK reviewed the literature, collected data, and wrote the first draft. HA edited the initial draft. All authors contributed to, reviewed, and approved the final draft of the paper. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.Figure 3: Pretreatment image (a), vertebrae appear flattened with reduced height, increased intervertebral spaces, superior and inferior beaking (black arrow), and osteopenic changes with sclerotic margins. Post-treatment image (b), vertebral height and bone density have improved, with resolution of sclerotic margins and partial improvement in the beaked appearance (black arrow)