Miguel Reyes-Múgica

A translocation causing increased alpha-klotho level results in hypophosphatemic rickets and hyperparathyroidism.

Phosphate homeostasis is central to diverse physiologic processes including energy homeostasis, formation of lipid bilayers, and bone formation. Reduced phosphate levels due to excessive renal loss cause hypophosphatemic rickets, a disease characterized by prominent bone defects; conversely, hyperphosphatemia, a major complication of renal failure, is accompanied by parathyroid hyperplasia, hyperparathyroidism, and osteodystrophy. Here, we define a syndrome featuring both hypophosphatemic rickets and hyperparathyroidism due to parathyroid hyperplasia as well as other skeletal abnormalities. We show that this disease is due to a de novo translocation with a breakpoint adjacent to α-Klotho, which encodes a β-glucuronidase, and is implicated in aging and regulation of FGF signaling. Plasma α-Klotho levels and β-glucuronidase activity are markedly increased in the affected patient; unexpectedly, the circulating FGF23 level is also markedly elevated. These findings suggest that the elevated α-Klotho level mimics aspects of the normal response to hyperphosphatemia and implicate α-Klotho in the selective regulation of phosphate levels and in the regulation of parathyroid mass and function; they also have implications for the pathogenesis and treatment of renal osteodystrophy in patients with kidney failure.

Total Parenteral Nutrition induced Liver Pathology: An Autopsy Series of 24 Newborn Cases

Total parenteral nutrition (TPN)-induced liver injury is a common complication in neonates managed with newborn intensive care. In several of these cases, irreversible and even fatal liver damage may develop, with patients dying of liver failure. In spite of multiple studies over several years, the pathogenesis of TPN-induced liver damage remains poorly understood. Clinical data from 24 neonates with clinical history of receiving TPN who died at Yale—New Haven Children’s Hospital and had autopsies performed, were collected by medical record review without knowledge of liver pathology findings. Liver histological sections from these patients were evaluated for multiple parameters without knowledge of the clinical course. Continuous data were analyzed by Wilcoxon signed-rank test and Mann-Whitney test, and dichotomous data by Fisher’s exact test; P < 0.05 was considered significant. Different histopathological abnormalities with varying degrees of severity were observed. A progression in the severity of histopathological changes in relation to duration of TPN administration (DTPN) was found. While patients with DTPN of < 2 wk had no fibrosis or only mild degrees of fibrosis, patients with more than 6 wk of DTPN developed moderate-to-severe fibrosis. Similar results were observed for cholestasis and bile duct proliferation. We did not find significant differences for birth weight, gestational age, occurrence of necrotizing enterocolitis, sepsis, or enteral feedings between the group with normal-to-mild liver changes (n = 16), and the group with moderate-to-severe liver changes (n = 8). On the other hand, DTPN was significantly different between these two groups (P = 0.008). Also, patients small for gestational age (P = 0.003) and patients with bronchopulmonary dysplasia (P = 0.001) were more commonly seen in the group with moderate-to-severe histopathological findings. Intracellular copper was detected in 12.5% of patients with moderate-to-severe liver changes, and was found in 50% of patients with normal-to-mild liver findings (P = 0.04). Detection of copper from tissue sections also decreased with DTPN, being observed in 57% of patients with < 2 wk DTPN and in none of the patients with > 12 wk DTPN. Our findings confirm the known significant relationship between the duration of TPN and liver injury. While previously described associations with birth weight, gestational age, enteral feedings, necrotizing enterocolitis, and sepsis were not noted, our study suggests that poor intrauterine growth may be a significant clinical risk factor for TPN-induced liver injury. In addition, our findings suggest that copper may have a protective effect against the development of TPN-induced liver damage.

An Osteoclast-Rich Tumor of the Gastrointestinal Tract with Features Resembling Clear Cell Sarcoma of Soft Parts: Reports of 6 Casesof aGIST Simulator

Six cases are reported of an osteoclast-rich tumor of the gastrointestinal tract that should be segregated from GIST. Five of the cases were located in the small bowel and one in the stomach. The age of the patients ranged from 13 to 37 years. The tumors behaved aggressively, with metastases to regional lymph nodes, liver, and other intraabdominal sites. Microscopically, the tumor cells were medium-sized, predominantly oval, relatively monomorphic, diffusely immunoreactive for S-100-protein, and negative for CD1 17, CD34, HMB-45, and Mart-i. They were admixed with scattered osteoclast-like, multinucleated giant cells which were S-100-protein negative and KPIpositive. One case studied cytogenetically had the karyotype 46XX t(I2;22)(qI3;q12). The cases here reported are interpreted as examples ofa distinctive type of gastrointestinal neoplasm which shares somefeatures with clear cell sarcoma of soft parts (melanoma of soft parts), including in one case the chromosomal translocation that is characteristically associated with that entity.

Early presentation of metastatic medullary carcinoma in multiple endocrine neoplasia, type IIA : Implications for therapy

A girl 5 years 11 months of age, belonging to an extensive kindred with multiple endocrine neoplasia, type IIA (MEN IIA), was found to have multifocal medullary thyroid carcinoma with metastasis in one paraglandular lymph node after positive findings on a calcium-pentagastrin stimulation test. Her sister, 3 years 8 months of age, also had an elevated calcitonin level, and thyroidectomy revealed C-cell hyperplasia and a focus of medullary thyroid carcinoma. These two cases underscore the need for prophylactic thyroidectomies in MEN IIA patients as young as 5 years of age and strict yearly provocative screening beginning at age 1 year.

Surveillance for Early Detection of Aggressive Parathyroid Disease: Carcinoma and Atypical Adenoma in Familial Isolated Hyperparathyroidism Associated With a Germline HRPT2 Mutation

Familial hyperparathyroid syndromes involving mutations of HRPT2 (also CDC73), a tumor suppressor, are important to identify because the relatively high incidence of parathyroid malignancy associated with such mutations warrants a specific surveillance strategy. However, there is a dearth of reports describing experience with surveillance and early detection informed by genetic insight into this disorder.

Rhabdomyosarcoma, Wilms tumor, and deletion of the patched gene in Gorlin syndrome

Background A 5-year-old year girl with a medical history of mental retardation, physical abnormalities and a known interstitial deletion of chromosome 9q22–q32 presented with a palpable suprapubic mass. During ultrasound investigation, a left renal mass was also detected. The patient underwent surgical removal of both neoplasms, which were diagnosed as a rhabdomyosarcoma and a Wilms tumor. Seven years later, she presented with macroglossia and a benign mandibular cyst.Investigations Physical examination, karyotyping, abdominal and pelvic ultrasound, brain CT scan, anatomic pathology analysis with immunohistochemistry, and typing of polymorphic markers in the patched (PTCH) gene region.Diagnosis Gorlin syndrome with synchronous rhabdomyosarcoma and Wilms tumor.Management Left nephrectomy, excision of paravesical tumor, excision of mandibular cysts, chemotherapy, and radiotherapy.

Phosphaturic Mesenchymal Tumor-Induced Rickets

ABSTRACT We describe two prepubertal girls with oncogenic rickets. The first patient, 9 years of age, presented with recent-onset lower-extremity pain. The second girl, presented at 4 years of age following a 9-month period of muscle weakness, bone pain, and poor linear growth. Laboratory analyses in both patients revealed hypophosphatemia and hyperphosphaturia; elevated circulating alkaline phosphatase activity was present in one of them. Radiographic evidence of a generalized rachitic process was evident in both cases. Computerized tomography of the paranasal sinuses and facial bones in patient 1 revealed a small lesion eroding through the inner table of the left mandibular ramus. Microscopic examination of this mass revealed a spindle cell neoplasm with chondroid material, dystrophic calcification, and both osteoclast-like and fibroblast-like cells. Prominent vascularity and marked atypia were present. These features are consistent with a phosphaturic mesenchymal tumor of the mixed connective tissue variant. In the second patient, computerized tomography revealed a lytic lesion located in the right proximal tibia, with histologic features consistent with a phosphaturic mesenchymal tumor of the nonossifying fibroma-like variant. Resection of each tumor resulted in rapid correction of the phosphaturia and healing of the rachitic abnormalities. A careful search for small or occult tumors should be carried out in cases of acquired phosphaturic rickets.

A Role for Macrophage Migration Inhibitory Factor in the Neonatal Respiratory Distress Syndrome

Using a mouse model of neonatal respiratory distress syndrome (RDS), we demonstrate a central role for macrophage migration inhibitory factor (MIF) in lung maturation at the developmental stage when human neonates are most susceptible to RDS. We prematurely delivered mouse pups at embryonic day 18, during the early saccular stage of pulmonary development. Only 8% of the prematurely delivered pups genetically deficient in MIF survived 8 h vs 75% of wild-type controls (p < 0.001). This phenotype was corrected when pups of all genotypes were bred from dams heterozygote for MIF deficiency. Local production of MIF in the lung increased at embryonic day 18, continued until full-term at embryonic day 19.5, and decreased in adulthood, thus coinciding with this developmental window. The lungs of pups genetically deficient in MIF were less mature upon histological evaluation, and demonstrated lower levels of vascular endothelial growth factor and corticosterone – two factors that promote fetal lung maturation. In vitro studies support a role for MIF in surfactant production by pulmonary epithelial cells. In a cohort of human neonates with RDS, higher intrapulmonary MIF levels were associated with a lower likelihood of developing bronchopulmonary dysplasia, a sequelae of RDS (p < 0.03). This study demonstrates for the first time a role for MIF in lung maturation, and supports a protective role for MIF in newborn lung disease.

Congenital primary cutaneous rhabdomyosarcoma in a neonate.

Abstract: We report a case of congenital primary cutaneous rhabdomyosarcoma, solid alveolar type, presenting as a solitary skin lesion on the right upper lip of a 2‐week‐old infant boy. Rhabdomyosarcoma originates from the embryonic mesenchyme precursor of striated muscle. Histologically it belongs to the group of “small round cell tumors.” Its myogenic origin is ascertained by immunohistochemical studies positive for myogenin, muscle‐specific actin, desmin, and myoglobin. Malignancy in the neonatal period is uncommon and the clinical management presents considerable challenges. Congenital alveolar rhabdomyosarcoma is a highly malignant tumor with no record of long‐term survivors. Treatment options include chemotherapy, excision, and radiotherapy. This infants tumor was responsive to chemotherapy and surgery and he was free of disease at the 6‐month follow‐up.

Mesenchymal hamartoma of the liver associated with features of Beckwith-Wiedemann syndrome and high serum alpha-fetoprotein levels.

A 5-month-old girl with clinical features of Beckwith-Wiedemann syndrome (BWS), including a repaired omphalocele, an earlobe crease, enlarged adrenal glands, renal size discrepancy, and hyperinsulinemic hyperglycemia, presented with a 1.9-cm liver nodule. Markedly increased serum alpha-fetoprotein (AFP) levels (1 060 000 mg/L), highly suspicious for hepatoblastoma, were detected, and resection of the liver mass was performed. Histologic sections showed features characteristic of a mesenchymal hamartoma of the liver (MHL). No features of embryonal or fetal hepatocellular proliferation or heterologous stromal components were noted. By immunohistochemistry, the hepatocytes expressed AFP, but no nuclear accumulation of β-catenin was present. Electron microscopy revealed normal, mature hepatocytes. Here we address the diagnostic challenge of the uncommon association of MHL and BWS in the setting of markedly elevated serum AFP levels. In addition, we analyze the unusual pancreatic lesion (focal endocrine adenomatosis) leading to severe hyperinsulinemic hypoglycemia in a patient with possible BWS. We emphasize that MHLs may present with markedly increased serum AFP levels, mimicking hepatoblastomas, and may also be part of the expanding spectrum of findings of BWS.