Congenital syphilis presenting with granulomatous scalp nodules.

We describe a case of congenital syphilis in an adopted infant with a unique dermatologic presentation of scalp granulomas, along with lymphadenopathy, anemia, and elevated liver transaminases. To our knowledge, this cutaneous morphology has not been previously reported in the literature. This case highlights the varied clinical presentation of congenital syphilis and the diagnostic challenge it poses for clinicians, especially in the context of unknown prenatal history/unknown risk factors, or if syphilis is acquired during pregnancy after routine screening is performed. As the incidence of congenital syphilis has more than tripled in recent years, this diagnosis should be considered when a neonate or infant presents with unexplained skin nodules.

Clinicopathological features of C3 glomerulopathy in children: a single-center experience.

BACKGROUND: C3 glomerulopathy (C3G) is defined by dominant glomerular deposition of C3 and minimal or no immunoglobulin, with two subtypes-dense deposit disease (DDD) and C3 glomerulonephritis (C3GN)-distinguished by features on electron microscopy (EM). Given that this rare disease has generally unfavorable yet highly variable outcomes, we sought out to review the histopathology, complement/genetic studies, and renal outcomes of pediatric patients with C3G at our institution. METHODS: All native kidney biopsies performed in a single pediatric hospital over a 10-year period were reviewed for features of C3G. Of 589 biopsy reports, we identified 9 patients fulfilling the diagnostic criteria for C3G and retrospectively reviewed their clinical chart and renal biopsy findings. RESULTS: We identified 4 patients with DDD, 4 with C3GN, and 1 indeterminate case, with features of both C3GN and DDD. Five patients were positive for one or more nephritic factors (C3NeF, C4NeF, C5NeF) with 1 patient additionally positive for complement factor H (CFH) autoantibody. Genetic testing done in 5 of the 9 patients failed to identify any causative mutations. Three patients showed progressive renal dysfunction over a mean follow-up period of 33 months. CONCLUSIONS: Complement and genetic studies are now routinely recommended for patients with a histopathological diagnosis of C3G. Careful interpretation of these studies and their prognostic and therapeutic implications in conjunction with biopsy findings is needed to further understand the pathophysiology of this rare disease in children.

EGFR Exon 20 Insertion/Duplication Mutation in Fibrous Hamartoma of Infancy With Predominantly Pseudoangiomatous Pattern Mimicking Giant Cell Fibroblastoma.

We describe a case of fibrous hamartoma of infancy (FHI) with predominant pseudoangiomatous histologic pattern that harbors a recently described characteristic molecular feature of FHI: EGFR exon 20 insertion/duplication mutation. A left axillary mass of an 8-month-old male was biopsied. Microscopic findings revealed a CD34-positive spindle cell proliferation accompanied by slit like spaces within collagen, mimicking giant cell fibroblastoma. The mass was excised. The vast majority of the mass showed histologic findings similar to the biopsy. However, the peripheral rim of the mass demonstrated focal triphasic histology suggestive of FHI. Giant cell fibroblastoma was excluded by a negative COL1A1/ PDGFB fusion by reverse transcriptase-polymerase chain reaction. Targeted Sanger sequencing revealed the presence of an EGFR exon 20 insertion/duplication mutation. We posit that identification of the characteristic EGFR exon 20 molecular aberration may be of diagnostic value in FHI with variant histology and help exclude more aggressive diagnoses.