the dermoid cyst associated with sinus opening located over the skin of the nose was termed as nasal dermal sinus - cyst by sessions in 1982 . it represents very uncommon congenital anomalies with dermoid cyst located in the frontobasal area and nasal dermal sinus . dermal sinus of occipital region or lumbar region associated with dermoid is well known . however , nasal dermal sinus is extremely rare and accounts for about 10% of head and neck sinus . intracranial extension of a nasal sinus is extremely rare and the sinus tract usually traverses either the foramen ceacum or the cribriform plate and further extends to get attached to dura or forms of a cyst within the falx cerebri . anterior neuropore defective closure leads to a defect in anterior cranial fossa floor , i.e. , foramen caecum , cribriform plate , ethmoid bones , and sphenoid . a 2-year - old toddler presented with complaints of a turbid - colored discharge from twin sites including medial canthus of the left eye and dorsum nasal bridge [ figure 1a ] since birth . on admission , he was conscious and normal neurological examination and normal developmental milestones . ( a ) photograph showing dermal sinus at medial canthus of the left eye and another at dorsum of nose in a 2-year - old child . ( b ) photograph of the excised specimen ( c ) intra - operative photograph showing interfalcial dermoid cyst in the relation to falx after retraction of the right frontal lobe noncontrast computed tomography ( ct ) scan head revealed a hypodense well - delineated mass lesion in the interfalcial with defect in the cribriform plates with extension of sinus tract [ figure 2 ] . magnetic resonance imaging ( mri ) brain axial section t2-weighted image showing interfalcine mass lesion with extension through cribriform plate and further , sinus tract better delineated in sagittal section [ figure 3a and b ] . computed tomography scan head of 2-year - old toddler showing hypodense lesion in the anterior cranial fossa floor magnetic resonance imaging brain of interfalcial dermoid with sinus tract in a 2-year - old boy . ( a ) t2-weighted image axial section showing the interfalcial dermoid ( black arrow ) . ( c ) t2 sagittal image even displaying and sinus tract and dermoid cyst ( arrow ) he underwent bicoronal scalp flap and fronto - orbital craniotomy after dural opening and retracting right frontal lobe laterally the yellowish white - colored encapsulated dermoid was visualized . the dermoid was attached to leaflet of the falx [ figure 1b ] after opening capsule , the cheesy white materials with hairs were evacuated and capsule was also completely excised [ figure 1c ] . the sinus tract was well defined and excised ; it was found to be attached to the sinus near the medial canthus of the left eye . he had no fresh discharges till last follow - up after 16 months following the surgical procedure . the sinus tract can externally open at any location on the skin of nose between the glabella and base of the columella . discharging sinus is a common symptom for seeking medical advice ; however , neglected cases may present with either manifestation of local infections , i.e. , periorbital and nasal cellulitis , nasal abscess , anomalies of nose , or osteomyelitis . unfortunately in the neglected cases , infection to the intracranial cavity can produce features of meningitis , abscess , or cerebrospinal fluid leaks . observed dermal sinuses located in the cranial region are rare and usually occur in the posterior fossa and placed along the midline , and laterally placed cranial dermal sinus is also extremely rare . the authors could find only two cases of laterally placed dermoid sinus including their one case in the literature search , who had dermoid in the temporal region having multiple sinuses , but none in the frontonasal region . multiple sinuses located in the canthus and dorsum of nose are not reported till date . however , current case had twin nasal dermal sinuses with associated intracranial dermoid located in the interfalcial region and constitute an interesting first case in the world literature of frontonasal region twin sinus associated with falcine dermoid , who underwent successful surgical repair . neuroimaging feature suggesting intracranial extension are intracranial soft tissue masses and associated bony changes may be widened nasal septum , bifid crista galli , and defects in the cribriform plate . the differential diagnosis of nasal dermal sinus includes dermoid , epidermoid , inflammatory granuloma , and neoplasms . surgical approach may require cranial exposure , nasal approach , or a combination of the two , and is dictated by the location of dermoid and extent of sinus tract . histologically , dermoid cyst contains both ectoderm and the mesodermal derivatives , typically the presence of keratinizing squamous epithelium is associated with hair , smooth muscle , sebaceous and sweat glands , and adipose tissue . early diagnosis with suspicion of intracranial extension must be kept as possibility and providing prompt diagnosis and management can result in good outcome and spare from complication of neglected infective complications . the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s ) has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal . the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed . the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s ) has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal . the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed .
twin nasal dermal sinus with associated intracranial dermoid located in interfalcial region is a very rare occurrence and is reported only in the occipital and temporal regions . 
 however , multiple sinuses located in the canthus and dorsum of nose are not reported till date . 
 authors report an interesting first case of interfalcial dermoid cyst associated with twin discharging dermal sinuses , who underwent successful surgical repair in the world literature . 
 the authors report the management of an unusual case and the review has been discussed briefly .