A 2-year-old girl presented to the otorhinolaryngologydepartment of Grant Medical Foundation, Pune, India, forevaluation of a congenital facial abnormality, with a trunk-like process arising from medial canthus of the left eye andabsent ipsilateral nostril (Fig. 1). The child was referred forimaging evaluation (HRCT and MRI) of the abnormality andto document any associated intra/extracranial anomalies.
Computed tomography scan revealed left-sided sinonasalaplasia with complete absence of the left nasal cavity,maxillary sinus, and ethmoid sinuses. The lateral probosciswas seen as a well-defined trunk-like outgrowth measuring25 mm in length and 14 mm in maximum transverse diameter(Fig. 2A). It was seen arising from the superomedial wall ofthe left orbit through a well-formed bony canal (Fig. 2B).
Magnetic resonance images showed the lateral probosciswith its secretory mucosal lining (Fig. 3A). Coronal T2-weighted images also revealed absent olfactory bulb/olfactory sulcus and olfactory tracts on the left side. (Fig.3B) A left paramedian cleft palate was also identified. Awell-defined lesion was seen in the inferomedial compart-ment of the left orbit measuring 13 × 17 mm. It appeared as asoft tissue density lesion on CT images. The lesion showedan intermediate signal intensity on T1-weighted images andappeared hyperintense on T2-weighted images (Fig. 4).Multiplanar CT and MRI images of the brain did not revealevidence of any associated intracranial abnormality. Nocommunication tract was detected through any anterior skullbase bony defect with the proboscis.
2. Discussion
Proboscis lateralis (PL) is a rare sporadic craniofacialmalformation first defined by W. Foster in 1861 in his
Fig. 1 Clinical photograph (A) and 3D reformatted CT image (B) of the patient showing the tubular trunk-like process arising from medialcanthus of left orbit with absent left nasal cavity.
Fig. 2 Axial HRCT image (A) showing a tubular trunk-like process (white arrow) arising from superomedial aspect of the left orbit withaplasia of ipsilateral nasal cavity and maxillary/ethmoid sinuses (open arrows). Coronal HRCT image (B) shows well-formed bony canal insuperomedial compartment of the left orbit (black arrowhead).
Fig. 3 T1W coronal MR image (A) showing the left-sided proboscis (white arrow). T2W coronal MR image (B) showing normal rightolfactory bulb (white block arrow) and hypoplastic left olfactory groove with absent left olfactory bulb (black arrow).
454 S. Vaid et al.
Fig. 4 Sagittal HRCT (A): left intraorbital soft-tissue density lesion (white asterisk). Sagittal MR images show left-sided intraorbital lesion(white asterisk) with intermediate signal intensity on T1W sequence (B), appearing hyperintense on short tau inversion recovery sequence (C).
455Proboscis lateralis with ipsilateral olfactory pathway
monograph “Congenital Malformations of The HumanBody” [1]. It has a reported incidence of less than1:100,000 [2], occurring in isolation or in association witha wide spectrum of anomalies including hemisinonasalaplasia spectrum, atypical cleft syndrome, abnormalities ofeye/ocular adnexa, mental retardation, corpus callosumagenesis, and encephaloceles [3,4]. The detailed anatomicalfindings were reported first by Selenkoff [5] in 1884.
It occurs because of a developmental defect of the nasalplacode, which is considered to be the primary organizer ofthe nose. Embryologic insult during the fifth week ofgestation, when the primitive nasal placode is converted tonasal pits, is considered responsible for development of theproboscis lateralis. This is usually associated with affectionof ipsilateral paranasal sinuses and nasolacrimal systembecause of closely related development of these structures[6,7]. Olfactory nerves and differentiation of the rhinen-cephalon may also be affected as the nasal placodes areresponsible for their development too [8]. Absence of anyone of the nasal placodes results in heminasal aplasia and,hence, is a frequent finding with proboscis lateralis [9].
Khoo [3] collected 34 cases from literature including one ofhis own and divided them clinically into 4 groups: Group 1: PLwith normal nose (least common); Group 2: PLwith ipsilateraldeformity of nose; Group 3: PL with ipsilateral deformity ofthe nose, eye, and/or ocular adnexa (most common); andGroup 4: PL with ipilateral deformity of the nose, eye, and/orocular adnexa with associated cleft lip and/or cleft palate.
Based on this classification, we categorized our patient toGroup 4 with proboscis lateralis, ipsilateral deformity of thenose, orbital lesion, and cleft palate.
Although Rontal and Duritz [10] have mentionedassociated absence of the ipsilateral olfactory pathway intheir list of 17 anomalies reported in the complete proboscislateralis syndrome, no image documentation of this finding isavailable in the literature to date. We have, however,documented associated ipsilateral absence of the olfactorybulb/sulcus and the olfactory tract in this patient.
Surgery involves a multistage procedure with a multidis-ciplinary approach. Repair of the deformity is undertaken
after complete facial growth. The repair is facilitated byreconstruction of the nose using the proboscis trunk. Hence,it is advisable to preserve the trunk. The proboscis is an idealdonor structure, with a good color and texture match withwhich to reconstruct the heminose. Bone and cartilage graftsare necessary for support [11].
3. Conclusion
Multimodality imaging is essential for preoperativeevaluation of the local sinonasal anomaly and to identifyall the components of this rare congenital facial abnormality.HRCT and MRI compliment each other with CT depictingexquisite bony details and MRI allowing optimal evaluationof mucosal lining of the proboscis, associated orbital lesions,and intracranial anomalies.
References
[1] Foster W. Congenital malformations of the human body, operations forremedying deformities of the lips, consequent on congenitalmalformation, accident, or disease. Dublin Q J Med Sci 1861;32(1):45-52, doi:10.1007/BF02944053.
[2] Harada T, Muraoka M. Proboscis lateralis: a rare bilateral case. AnnPlast Surg 2001;47(3):350-1.
[4] Belet N, Belet U, Tekat A, Küçüködük U. Proboscis lateralis:radiological evaluation. Pediatr Radiol 2002;32(2):99-101 [Epub 2001Dec 8].
[5] Selenkoff A. Ein Fall von Arhinencephalia unilateralis bei einemerwachsenen Manne. Virchows Arch[Pathol Anat] 1884;95:95.
[6] Guerrero J, Cogen M, Kelly D, Wiatrak B. Clinicopathologic reports,case reports, and small case series. Proboscis lateralis. ArchOphthalmol 2001;119:1071-80.
[9] Van Kempen AA, Nabben FA, Hamel BC. Heminasal aplasia: a casereport and review of the literature of the last 25 years. ClinDysmorphol 1997;6(2):147-52.
[10] Rontal M, Duritz G. Proboscis lateralis: case report and embryologicanalysis. Laryngoscope 1977;87:996-1006.
[11] Brown K, Brown OE. Congenital malformations of the nose. In:Cummings CW, editor. Pediatric otolaryngology, head and necksurgery, 3rd ed., 5. St Louis: Mosby; 1998. p. 92-103.
