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H Liapis

Publications and source records attributed to H Liapis.

42 records · Page 3Linked to original sources
PubMed1987

Midline cervical cysts in children. Thyroglossal anomalies.

Deep, midline cervical cysts clinically diagnosed as thyroglossal duct cysts (TDCs), have been pathologically classified as dermoid cysts because of the presence of skin appendages and a squamous epithelial lining. In 75 midline cervical masses preoperatively diagnosed as TDC, we could classify only 54 as TDC, using the preexisting criteria of squamous or ciliated columnar epithelial lining associated with a tract or thyroid follicles. Eleven cysts were reclassified as dermoid, and six were called "mixed" because of features of both dermoid cysts (skin appendages) and TDC (epithelial tract or thyroid follicles). The morphological similarity of all these lesions suggests a common origin, perhaps from totipotential tissue entrapped during the descent of the embryonic thyroglossal duct from the base of the tongue. We conclude that these lesions should be grouped together under the eponym of "thyroglossal anomalies," and that treatment for all should consist of the Sistrunk procedure.

Adolescent↗
PubMedDate not supplied

p53 and Ki-67 proliferating cell nuclear antigen in benign and malignant peripheral nerve sheath tumors in children.

Malignant peripheral nerve sheath tumors (MPNSTs) are uncommon soft tissue tumors. In children with neurofibromatosis 1 (NF1), a MPNST often arises in a pre-existing neurofibroma, or may represent an initial manifestation without other obvious stigmata of the disease. The development of MPNSTs may be associated with instability of the p53 tumor suppressor gene since it is the most frequent genetic abnormality in soft tissue sarcomas. To assess the presence of p53 accumulation in MPNSTs and its correlation with clinical and pathologic features, we studied 12 neurofibromas (NFs), including 4 tumors with cellular features (one congenital) and 10 MPNSTs. Six MPNSTs were associated with NF1, all of which developed within a plexiform neurofibroma. Cell proliferation evaluated with an antibody to Ki-67 and nuclear p53 staining were both detected by immunohistochemistry. We found p53 positivity in 60% of MPNSTs. All NFs except the congenital tumor were p53 immunonegative (P < 0.01). Rare p53-positive nuclei were detected in the transitional zone in two of six MPNSTs arising in plexiform NFs. Ki-67 distinguished the NFs from MPNSTs (P < 0.005). Half of the NF1 patients with p53-positive MPNSTs developed recurrence or metastases or developed a second malignancy within 2 years of diagnosis, whereas patients with p53-positive sporadic MPNSTs were free of disease 1 to 7 years later. We found p53 accumulation more frequently in NF1-associated MPNSTs. p53 mutations may be an additional biologic factor to account for the poor prognosis in these tumors.

Adolescent↗
PubMedDate not supplied

Phenotype/genotype correlations in the ultrastructure of monogenetic glomerular diseases.

Electron microscopy defined classic patterns of hereditary glomerular disease long before genetics revealed an underlying specific mutation. Genetic analysis is now easier to perform in clinical practice but an earlier optimism that genetics would predict disease severity and phenotype is challenged. The classic paradigm is Alport nephritis in which only a subset of mutations may predict glomerular abnormalities and disease severity. Interpretation of ultrastructural pathology of monogenetic diseases like Alport nephritis is complicated when the proband is the first family member to be diagnosed or there is discrepancy between clinical presentation and ultrastructural changes. In this review the authors have selected a dozen cases representative of common monogenetic glomerular diseases as a platform to discuss the utility of diagnostic electron microscopy in the era of molecular genetics. The emphasis is on genotype/glomerular phenotype correlations.

Adolescent↗
PubMedDate not supplied

In situ hybridization of human erythropoietin in pre- and postnatal kidneys.

Due to the transient transcription of the gene of erythropoietin (EPO) in response to hypoxic stimuli, localization within the cell of origin in humans has not been possible. Under acutely induced transcription of the EPO gene, through severe bleeding (hematocrit < 10%), EPO transcripts were detected within renal interstitial cells in rodents. However, by immunohistochemistry or tissue culture, human tubular epithelial cells or glomerular mesangium have been shown to produce EPO, suggesting a species difference. Aiming to investigate the precise location of EPO in intact human kidneys, 38 fetal, infant, and adult kidneys were examined by in situ hybridization. Kidneys from patients with conditions predisposing to severe hypoxia and/or induced polycythemia were utilized, because under these conditions active EPO mRNA synthesis is expected. We found specific EPO mRNA transcripts within a small population of cortical interstitial cells of near-term or postnatal kidneys.

Adult↗