Pediatric and Developmental Pathology最新文献

Shwachman-Diamond Syndrome (SDS) is a rare autosomal recessive genetic condition with 90% of cases associated with biallelic pathogenic variants in the Shwachman-Bodian-Diamond Syndrome (SBDS) gene on chromosome 7q.11.21. SDS belongs to ribosomopathies since SBDS gene encodes a protein involved in ribosomal maturation. Its phenotypic postnatal hallmark features include growth delay, bone marrow failure, exocrine pancreatic insufficiency, and skeletal abnormalities. We report a first fetal case of Shwachman-Diamond syndrome and extend its phenotype before birth. The clinical features mimicked vascular growth restriction with FGR and shortened long bones, associated with abnormal Doppler indices. Non-restricted fetal autopsy after termination of pregnancy allowed deep phenotyping disclosing the features of fetal skeletal dysplasia. Post-fetopathological trio exome sequencing identified biallelic pathogenic variants in the SBDS gene. Genotype-phenotype correlations confirmed the diagnosis and enabled an adequate genetic counseling of the parents. Our case is another example of the positive impact of fetal autopsy coupled with post-fetopathological genomic studies, even in the cases that were hitherto classified as maternal or fetal vascular malperfusion.

Umbilical cord hemangiomas are rare lesions, for which data on pregnancy outcome is lacking. This study combines a multi-institution 4-case series with a systematic literature search (n = 52) to determine possible pathologic lesion parameters which may have an effect on pregnancy outcome. Of all 56 pregnancies, lesion size ranged from 0.2 to 23.0 cm with pregnancy outcomes ranging from healthy liveborns (58.9%), liveborns with severe complications largely due to prematurity and/or fluid overload (12.5%), intrauterine/neonatal demise (25.0%), and pregnancy termination (3.6%). Of the 52 cases included for statistical analysis, there was no significant association between fetal outcome and vascular lesion location (P = .12) or fetal outcome and single umbilical artery involvement versus involvement of other vasculature (P = .29). The mean length of vascular lesions that resulted in healthy liveborns did not significantly differ from those resulting in severe fetal complications and/or demise (P = .72). Cases resulting in severe complications and/or demise were significantly earlier at delivery than those resulting in healthy liveborns (P < .001). Combined findings suggest that functional lesion characteristics, such as the degree of turbulent flow generated, have more significance than size, especially in early gestation losses. Moving forward, standardized reporting of pathologic lesion characteristics is paramount to better predict pregnancy prognosis.

Spindle cell/sclerosing rhabdomyosarcoma is an infrequent subtype of rhabdomyosarcoma according to the World Health Organization Classification of Soft Tissue and Bone Tumours, which includes a novel category of intraosseous spindle-cell rhabdomyosarcomas (ISCRMS) with EWSR1:: or FUS::TFCP2 fusions. We report a case of ISCRMS with EWSR1::TFCP2 fusion presenting in the femur mimicking osteosarcoma in this unusual primary location. We present an 18-year-old male with relapsed widely metastatic sarcoma, morphologically identical to osteosarcoma responding poorly to chemotherapy, initially presenting in the distal femur. Sections showed a high-grade malignant neoplasm with sheets of epithelioid and spindled cells without obvious rhabdomyoblastic differentiation morphologically containing focal areas resembling new bone/osteoid formation. Molecular sequencing identified t(12;22) EWSR1::TFCP2. The tumor cells were diffusely positive for pancytokeratin, MyoD1, and ALK by retrospective immunohistochemistry. Desmin and SATB2 were focally positive. Myogenin was negative, and INI-1 expression was retained. ISCRMS commonly involves craniofacial and pelvic bones, but rarely originates in long bones, as in this case. Initially, osteosarcoma was the primary diagnostic consideration based on distal long bone location, patient age, and evidence of osteoid formation. Distinction between the two entities may be nearly impossible on morphologic grounds alone, which presents a diagnostic pitfall without molecular or extensive immunoprofiling data.

Ebstein anomaly (EA) is a rare congenital heart defect characterized by abnormal development of the tricuspid valve (TV) and right ventricular myocardium. This study documents 2 dramatic cases of fetal EA characterized by hydrops and cardiomegaly, leading to intrauterine or early neonatal death. These clinical outcomes were associated with morphological abnormalities including severe tricuspid regurgitation, unguarded TV orifice, pulmonary atresia, and flattened right ventricular myocardium. This study highlights that these adverse anatomical features may result in unfavorable clinical outcomes in fetal EA. While timely identification of such features by prenatal ultrasound is crucial for providing accurate prognostic stratification and guiding treatment decisions, fetopsy may be necessary to discern EA among the spectrum of right-heart anomalies.

Background: Placental maternal vascular malperfusion (MVM) is characterized by accelerated villous maturation and has been associated with a decrease in the antiaging protein, alpha-klotho (AK). Our aim was to characterize AK protein and gene expression in the placenta and fetal organs.

Methods: We utilized 2 cohorts. First, we characterized AK protein expression in an autopsy cohort where cases were defined as MVM as the cause of fetal death compared to a stillborn control population. Second, we characterized placental and umbilical cord blood AK gene expression in a liveborn population with and without MVM.

Results: We found decreased protein expression in the villous trophoblastic cells of placentas exposed to severe MVM and decreased AK gene expression in placental tissue exposed to MVM. We did not see any statistically significant differences in fetal organ or umbilical cord blood AK expression based on the presence or absence of MVM. Furthermore, in liveborn infants, we also found increased odds of preterm birth with lower placental AK expression.

Conclusions: Decreased AK gene and protein expression in the placenta in the setting of MVM is consistent with the theory of placental aging in MVM and is associated with increased odds of preterm birth.

Background: Invasive fungal intestinal infections are rare in pediatric patients with limited studies reported to date.

Methods: Retrospective study of invasive intestinal fungal infections in pediatric patients. For fungal specification, 18S rRNA gene PCR was performed using formalin-fixed paraffin-embedded tissues.

Results: A total of 19 cases from 18 patients were included (13 males, 72%) with a median age of 20 days (8 days-14 years). About 13 patients (72%) presented within 67 days of birth and 11 patients (61%) were premature and 14 patients (78%) had a significant medical history. The most common location was the jejunum/ileum (56%) followed by the right colon and terminal ileum (22%). In 10 patients, the fungal elements were seen in the mucosa with 3 extending into the submucosa, and only 3 patients showed full-thickness involvement. Tissue necrosis and angioinvasion were seen in 13 (72%) and 8 (44%) patients, respectively. Morphologically, organisms consistent with Candida spp. were seen in 17 patients and with a mucoraceous mold in 1 patient. A 18S rRNA gene sequencing performed in 18 cases identified Candida dubliniensis in 16 cases and Candida spp. in 2 cases. During the study follow-up period, 56% of the patients died.

Conclusion: In our experience, most cases were due to Candida spp. and predominantly in premature infants and associated with poor outcomes.

Hereditary multiple intestinal atresia (HMIA) with TTC7A mutation is caused by homozygous or compound heterozygous TTC7A gene mutation. It is characterized by multiple small and large intestinal atresias and/or stenoses. TTC7A mutation is described in some patients with inflammatory bowel disease and mild-severe forms of severe combined immunodeficiency without intestinal atresia or stenosis. We present 2 cases of intestinal atresia and documented TTC7A mutation with a novel variant. Both cases had different clinical and pathological manifestations. The first case is a male infant born at 35 weeks of gestation with failure to pass meconium. Intestinal biopsy reveals apoptotic enteropathy with villous atrophy and increased mucosal eosinophils. The second case is referred at birth for antenatally detected umbilical hernia, polyhydramnios and possible upper intestinal obstruction. The resected specimen reveals ileal atresia with partial villous atrophy, decreased number of lamina propria inflammatory cells and absence of plasma cells. In conclusion, these cases reflect an emerging TTC7A pathogenic variant with different histological manifestations and leads to characterization as immune dysregulation disorder. There is a need to differentiate TTC7A mutation associated ones from cases labeled as very early onset IBD and rule out other hereditary immunodeficiencies.

Background: In a non-forensic hospital setting, neonatal death within the first week of life is often related to premature birth and/or lung diseases. Without post-mortem examination, the identification of the cause of death may be challenging. Autopsy can confirm the clinical diagnosis, uncover additional information or change the diagnosis. Our study aimed to assess the correlation between the clinical diagnosis and post-mortem findings in early neonatal deaths.

Methods: The retrospective study included autopsy cases with neonatal deaths within the first 7 days of life (arbitrary time interval 2006-2021). Discrepancies between clinical and histopathological findings were classified into 3 groups: (i) full agreement, (ii) additional findings discovered by autopsy, or (iii) autopsy changed the diagnosis.

Results: A cohort of 27 cases could be identified and lung pathologies were the most common finding (56%). Additional findings could be discovered in 48% of cases. Major discrepancies which changed the clinical diagnosis could be found in 11% (n = 3/27) of cases.

Conclusion: Frequently, post-mortem examinations validate the clinical diagnosis while revealing crucial information in a few cases. In these discrepant cases, autopsy findings can provide information for genetic counselling and quality control of clinical management.

Langerhans cell sarcoma (LCS), a rare malignant neoplasm in the general category of myeloid neoplasms characterized by overtly malignant Langerhans cells (LC) with conspicuous mitotic activity including atypical forms. Although most cases occur in adults, rare examples of LCS have been reported in children with variable clinical outcome. We present 2 childhood cases of Langerhans cell neoplasm with high grade sarcomatous features and OSBPL9::BRAF fusion and BRAF V600E mutation.