Clinicopathologic and molecular features of intracranial desmoplastic small round cell tumors

Desmoplastic small round cell tumors (DSRCTs) are highly aggressive sarcomas that most commonly occur intra-abdominally, and are defined by EWSR1-WT1 gene fusion. Intracranial DSRCTs are exceptionally rare with only seven previously reported fusion-positive cases. Herein, we evaluate the clinical, morphologic, immunohistochemical and molecular features of five additional examples. All patients were male (age range 6-25 years; median 11 years), with four tumors located supratentorially and one within the posterior fossa. The histologic features were highly variable including small cell, embryonal, clear cell, rhabdoid, anaplastic and glioma-like appearances. A prominent desmoplastic stroma was seen in only two cases. The mitotic index ranged from <1 to 12/10 HPF (median 5). While all tumors showed strong desmin positivity, epithelial markers such as EMA, CAM 5.2 and other keratins were strongly positive in only one, focally positive in two and negative in two cases. EWSR1-WT1 gene fusion was present in all cases, with accompanying mutations in the TERT promoter or STAG2 gene in individual cases. Given the significant histologic diversity, in the absence of genetic evaluation these cases could easily be misinterpreted as other entities. Desmin immunostaining is a useful initial screening method for consideration of a DSRCT diagnosis, prompting confirmatory molecular testing. Demonstrating the presence of an EWSR1-WT1 fusion provides a definitive diagnosis of DSRCT. Genome-wide methylation profiles of intracranial DSRCTs matched those of extracranial DSRCTs. Thus, despite the occasionally unusual histologic features and immunoprofile, intracranial DSRCTs likely represent a similar, if not the same, entity as their soft tissue counterpart based on the shared fusion and methylation profiles.

Undifferentiated sarcoma of the orbit with angiomyxoid features

A 7-month-old female infant developed a grade 3 un-differentiated sarcoma with angiomyxoid features of the right orbit. The tumor expanded rapidly 2 months after an initial sub-total resection and extended posteriorly toward the right cavernous sinus. After treatment with ifosphamide, doxorubicin, and proton beam radiation, there was no discernible residual tumor 20 months after starting chemotherapy.

Placental and fetal findings in intrauterine Candida lusitaniae infection following in vitro fertilization and embryo transfer

Intrauterine infection with non- albicans Candida species is rare but can be catastrophic to the fetus. A subset of intrauterine infections with non- albicans Candida species has occurred in women who have undergone in vitro fertilization and embryo transfer (IVF-ET). We report a case of a 33-year-old healthy woman, pregnant with triplets by in vitro fertilization, who experienced preterm premature rupture of membranes of fetus A at 16 weeks' gestation and subsequently developed oligohydramnios in all 3 fetuses. Following elective pregnancy termination, microscopic examination and molecular analysis demonstrated Candida lusitaniae chorioamnionitis and pneumonia in all 3 fetuses associated with granulomatous inflammation. Our case is only the 2nd report of C. lusitaniae chorioamnionitis and should raise awareness that C. lusitaniae intrauterine infection is associated with IVF-ET. We also show here that C. lusitaniae can cause granulomatous intraplacental inflammation and intrauterine pneumonia.