Prenatal detection of Pai syndrome without cleft lip and palate: a case report.

Summary: Prenatal detection of Pai syndrome without cleft lip and palate: a case report: Pai syndrome is a rarely encountered disease characterized by findings of median cleft lip, facial skin polyps, nasal mucosal polyps and midline central nervous system lipoma. We report a case with prenatal detection of a pericallosal lipoma and a skin tag on the forehead. After delivery, the diagnosis was confirmed as a case of Pai syndrome.Key-words: Pericallosal lipoma - Pai syndrome - Prenatal ultrasoundINTRODUCTIONIntracranial lipomas are rarely observed congenital malformations. They usually occur secondary to the abnormal differentiation of meninx primitiva layer, arachnoid and the inner layer of dura mater (5). They make up less than 0. 1% of all intracranial tumors in the literature. Twenty five-fifty percent of all intracranial lipomas are pericallosal lipomas with partial or complete agenesis of the corpus callosum in some of the patients (5). They can be observed in nodular or curvylinear forms and are usually asymptomatic (5).When an intracranial lipoma is coupled with a facial polyp, it may be suspicious for Pai syndrome. Pai syndrome is a rare disorder in which there are some other associated findings such as median cleft lip, facial skin and nasal mucosal polyps in addition to a midline intracranial lipoma (1,2, 6).CASE REPORTA 40 years old woman (gravida 13, para 12) at 28th week of pregnancy was referred to our perinatology unit because of a hyperechogenic structure in the brain of the fetus. Fetal biometrie measurements were appropriate for gestational age. Cranial ultrasonography revealed a hyperechogenic structure right above the septum pellucidum, neighboring the corpus callosum. Pericallosal artery was intact (Fig. 1). Further, an abnormally shaped nose and a polyp like structure were detected on the forehead (Fig. 2). There was no sign of cleft lip and palate. The rest of the neurosonographical examination was within normal limits. A preliminary diagnosis of pericallosal lipoma was made. The family history did not reveal any findings regarding mental retardation or congenital malformations and an offer of fetal karyotyping was declined by the parents.A male fetus (2740 g / 49 cm) was delivered by cesarean section on the 40th week of pregnancy. The Apgar scores at 1st and 5th minutes were 6 and 8 respectively. The baby did well without the need for neonatal intensive care unit. On physical examination there were dysmorphic features (Fig. 3) such as bifid nose, bilateral nostril polyps, skin tags at the midline of the forehead and on the preauricular area, wide nasal bridge, absence of right eyelid, lipoma on the conjunctiva and big and wide earlobes.Abdominal ultrasonography and otoaccustic emission tests revealed no pathology. On cranial MRI, a 30 mm wide lesion was observed in the pericallosal area, concordant with pericallosal lipoma and characterized with hyperintensity in all sequences. Chromosomal analysis of the peripheral blood cultures revealed a 46,XY normal karyotype.DISCUSSIONPai syndrome was first defined by Pai et al. in 1987 (10). Central nervous system lipomas, median cleft of the upper lip and facial skin polyps form the classic triad to define the syndrome, but the phenotype may be variable (13). A median cleft lip is a frequent finding in the previously reported Pai syndrome cases in the literature (3, 6, 13), however, it was not present in our case. Although the only cranial MRI finding in our patient was a pericallosal lipoma, computerized tomography and/or MRI show additional cranial structural anomalies in 85% of the cases with Pai syndrome (5, 9). For example, Guion et al. reported a Pai syndrome with a huge encephalocele, and the computerized tomography scan demonstrated a general disorganization of the cerebral parenchyma in addition to hydrocephaly in this patient (4). Despite this high rate of central nervous system pathologies, thus far serious neurological disorders such as mental retardation have been reported in only a few cases (8, 3). …