Background Symplastic hemangioma is a benign superficial abnormal buildup of blood vessels, with morphological features which can mimic a pseudo malignancy. A few cases have been reported in the literature. We report here, a unique case of calvarial symplastic hemangioma, which is the first case in the calvarial region. Case presentation A 29-year-old male patient, with a left occipital calvarial mass since childhood, that gradually increased in size with age, was associated with recurrent epileptic fits controlled by Levetiracetam (Keppra), with no history of trauma. He presented to the emergency room with a recent headache, vomiting, frequent epileptic fits and a decrease in the level of consciousness 1 day prior to admission. A CT scan showed three diploic, expansile, variable sized lytic lesions with a sunburst appearance; two that were biparietal, and one that was left occipital, which were all suggestive of calvarial hemangiomas. However, the large intracranial soft tissue content, within the hemorrhage of the occipital lesion was concerning. The patient had refused surgery over the years; however, after the last severe presentation, he finally agreed to treatment. The two adjacent, left parietal and occipital lesions were treated satisfactorily using preoperative embolization, surgical resection, and cranioplasty. Histopathology revealed cavernous hemangiomas, in addition to symplastic hemangioma (pseudo malignancy features) on top at the occipital lesion. The right parietal lesion was not within the surgical field; therefore, it was left untouched for follow-up. Conclusions Histopathology and radiology examinations confirmed the diagnosis as symplastic hemangioma, on top of a pre-existing cavernous hemangioma. To the best of our knowledge, this is the first case of a calvarial symplastic hemangioma, which we report here.

The present study aimed to determine genomic changes in sporadic intracranial hemangioblastoma (HBL), and the mutation patterns were analyzed using next-generation DNA sequencing (NGS). In this NGS analysis of the HBL tumor, 67 variants of 41 genes were identified. Of these, 64 were single-nucleotide variants (SNVs), two were exonic insertions and deletions (INDEL), and one was an intronic INDEL. In total, 15 were missense exonic variants, including an insertion variant in the NRAS gene, c.1_2insA, and a deletion variant, c.745delT, in the HNF1A gene, both of these mutations produced a termination codon. Other exonic missense variants found in the tumor were CTNNB1 , FGFR3 , KDR , SMO , HRAS , RAI1 , and a TP53 variant (c.430C>G). Moreover, the results of the present study revealed a novel variant, c.430C>G, in TP53 and two missense variants of SND1 (c.1810G>C and c.1814G>C), which were also novel. ALK (rs760315884) and FGFR2 (rs1042522) missense variants were reported previously. Notably, a total of 10 previously reported single-nucleotide polymorphisms (SNPs) were found in this tumor in genes including MLH1 (rs769364808), FGFR3 (rs769364808), two variants (rs1873778 and rs2228230) in PDGFRA , KIT (rs55986963), APC (rs41115), and RET (rs1800861). The results of this study revealed a synonymous mutation (SNP) in c.1104 G>T; p. (Ser368Ser) in the MLH1 gene. In this amino acid (AA) codon, two other variants are also known to cause missense substitutions, c.1103C>G; p. (Ser368Trp); COSM6986674) and c.1103C>T; p.(Ser368Leu; COSM3915870), were found in hematopoietic and urinary tract tissue, respectively. However, three SNPs found in genes such as ALK , KDR , and ABL1 in the HBL tumor in this study were not reported in UCSC, COSMIC, and ClinVar databases. Additionally, 19 intronic variants were identified in this tumor. One intronic SNV was present in each of the following genes: EGFR , ERBB4 , KDR , SMO , CDKN2B , PTEN , PTPN11 , RB1 , AKT1 , and ERBB2 . In PIK3CA and FBXL18 genes, two intronic variants were present, and in the SND1 gene, three intronic variants were detected in the HBL tumor presented in this study. Notably, only one of these was reported in the catalog of somatic mutations in canc...