Hypothalamic hamartoma and the Pallister-Hall syndrome.

The Pallister-Hall syndrome (PHS) was initially described as the congenital hypothalamic 'hamartoblastoma' syndrome in 1980. Cardinal manifestations of the syndrome consist of a hypothalamic hamartoma and extracranial abnormalities, initially thought to be fatal in the perinatal period. The original pathologic description of these hypothalamic lesions were from infants who died in the perinatal period and revealed small cells of variable density which resembled primitive undifferentiated germinal cells and appeared to invade the hypothalamic nuclei, suggesting a neoplastic potential. Hypothalamic lesions have now been removed from older infants and children with this syndrome and reveal a more mature histologic appearance typical of a hypothalamic hamartoma. We present 2 new cases of PHS who underwent surgery and demonstrate the maturational nature of the hypothalamic lesion and the phenotypic variability of the syndrome.

Familial Pallister-Hall syndrome: case report and hormonal evaluation.

Pallister-Hall syndrome is a usually lethal dysplasia/malformation syndrome characterized by hypothalamic hamartoblastoma, hypopituitarism, postaxial polydactyly, craniofacial malformations, imperforate anus, and other malformations. We report a familial case in a male infant and his female sib fetus, suggesting autosomal recessive inheritance, or germinal mosaicism for an autosomal dominant mutation, or a segregating submicroscopic chromosome abnormality. Detailed endocrine evaluation on the surviving infant revealed documented pituitary function, pituitary deficit, and hypothalamic deficiency. We suggest that hypothalamic dysfunction contributes to the hypopituitarism seen in Pallister-Hall syndrome.

Asymptomatic large hypothalamic hamartoma associated with polydactyly in an adult.

A hypothalamic hamartoma is a congenital tumor-like neural malformation. It is usually seen in children and is associated with neuroendocrinological symptoms, seizures, or psychological impairments. An asymptomatic hypothalamic hamartoma in an adult is extremely rare. This report describes an asymptomatic adult with a large hypothalamic hamartoma associated with polydactyly in his feet. Both polydactyly and hamartoma are rare lesions; therefore, this may not be a coincidental presentation. It is thought to have occurred in the embryonic period presumably between 37 and 40 gestational days.

Congenital hypothalamic hamartoma syndrome: nosological discussion and minimum diagnostic criteria of a possibly familial form.

We report on congenital hypothalamic hamartomas, discovered at autopsy in 3 unrelated fetuses. In the first 2 patients, the tumor was associated with skeletal dysplasia only. In the third patient, it was part of a non-random congenital malformation association, suggestive of Meckel syndrome. In one family, a previous boy died soon after birth with similar craniofacial and skeletal abnormalities. As far as we know, the association between isolated skeletal dysplasia and congenital hypothalamic hamartomas has not yet been documented in the literature. Nevertheless, a spectrum of skeletal abnormalities has been described in association with congenital hypothalamic "hamartoblastoma" and a constellation of variable visceral malformations under the eponym of "Pallister-Hall syndrome" (PHS). A detailed analysis of the PHS reported cases shows that only skeletal dysplasia and oro-facial abnormalities are present constantly. They show similarities with those found in our first 2 cases. These findings prompt us to consider skeletal dysplasia and oro-facial abnormalities as common denominator and minimum criteria required to define a nosologically distinct, possibly familial entity, which we suggest calling "congenital hypothalamic hamartoma syndrome" (CHHS).

Case report and delineation of the congenital hypothalamic hamartoblastoma syndrome (Pallister-Hall syndrome).

We report one new case of congenital hypothalamic hamartoblastoma syndrome (Pallister-Hall syndrome) and one case of a diencephalic nodule associated with craniofacial malformations. Based on a review of 11 cases of Pallister-Hall syndrome documented by pathological examination, two cases presumed by phenotype, three cases of hypothalamic hamartoma with craniofacial anomalies only, and several cases of related interest, we delineate the clinical, neuroradiologic, and neuropathologic manifestations which aid in differential diagnosis. Clinical manifestations in infants with Pallister-Hall syndrome included postaxial polydactyly with nail dysplasia, short nose with flat nasal bridge, apparently low-set, posteriorly angulated ears, kidney and lung anomalies, congenital heart defects, imperforate anus, and micropenis with undescended or hypoplastic testes in males. These manifestations were associated with varying degrees of panhypopituitarism and pituitary aplasia. In three cases of hypothalamic hamartoma associated with craniofacial anomalies only, the face resembled that of holoprosencephaly. Other cases of hypothalamic hamartoma have had associated palate or heart defects or presented with precocious puberty. Of the infants with a hypothalamic hamartoblastoma at autopsy, neuropathologic findings were consistent with a primitive neuroectodermal tumor. Surgical tissue from our sole survivor suggested such tumors might mature, and the tumor has not recurred. Neuroradiologic diagnosis may be difficult but should be attempted in infants with these clinical manifestations; due to the need for prompt initiation of appropriate therapy.

Congenital hypothalamic hamartoma associated with severe midline defect: a developmental field defect. Report of a case.

We describe a median "cleft" face anomaly (MCFA) with congenital hypothalamic hamartoma in a newborn girl. The MCFA was associated with a frontal midline skull lipoma and a complex congenital heart defect. Possible pathogenetic mechanisms are discussed, and a review of the pertinent literature is given. It is concluded that probably all malformations in our patient are disturbances of a single developmental field defect, ie, the midline.

A cluster of Pallister-Hall syndrome cases, (congenital hypothalamic hamartoblastoma syndrome).

We report on three infants with hand anomalies and congenital hypopituitarism. In two of the cases, a hypothalamic tumor was found; the third infant died without postmortem brain studies. Family history in the first case suggested possible familial recurrence; the mother's sister had died at 17 hr of age with polydactyly, microglossia, and flat nasal bridge (no autopsy done). Our second case was born by cesarean section after a pregnancy complicated by extremely low maternal estriols. At birth, hypopituitarism was diagnosed, a cranial CT scan was read as normal, and hormonal replacement was begun with thyroxine, hydrocortisone, and growth hormone. At 11.5 mo of age she developed seizures; and a repeat CT scan showed a mass extending beneath the hypothalamus. This tumor was removed surgically at 12 mo, the first successful treatment of this disorder. Our third possible case had a bifid epiglottis, hypopituitarism, and hand anomalies. A CT scan at birth failed to reveal a mass in the hypothalamus. This child died from complications of untreated hypopituitarism, and no neuropathology studies were done. These three cases were conceived between March 10th and April 17th in three different years in three geographically contiguous counties of Vermont. Clustering in time and space and possible familial recurrence, in one of these cases, suggest a possible gene/environment interaction.