Dorsal accessory ectopic breast with polythelia – A marker of occult spinal dysraphism

BACKGROUND: Accessory breast, also known as supernumerary breasts, polymastia, or mammae erraticae, is a clinical condition of having an additional breast. Accessory breasts are usually seen along the embryonic milk line, with the majority located in the axilla. Polythelia is the presence of an additional nipple. We report a rare case of dorsal accessory ectopic breast with three nipples (two well formed and one rudimentary) occurring along with lipomeningomyelocele and diastematomyelia. CASE DESCRIPTION: We report the case of an 18-year-old female who presented with chief complaints of swelling over the upper back since birth and spastic weakness of bilateral lower limbs with inability to walk since 2 years. Three-dimensional computed tomography scan of the dorsal spine was suggestive of a wide bony defect in the posterior spinal elements from D3 to D9 vertebrae. Diastematomyelia was also seen. Magnetic resonance imaging of the dorsal spine was suggestive of a complex spinal dysraphism with lipomeningomyelocele and diastematomyelia. During surgery, the patient's accessory breast was removed, lipomatous tissue and bony septum were excised, and dural repair was done. Histopathological examination was consistent with accessory ectopic breast with lipomeningomyelocele. CONCLUSION: Dorsal accessory breast, although a rare entity, whenever present should alert the clinician regarding the possibility of an underlying occult spinal dysraphism (OSD). Therefore, dorsal accessory breast can also be considered as a marker of OSD.