Intraoperative Consultations of Central Nervous System Tumors: A Review for Practicing Pathologists and Testing of an Algorithmic Approach.

Intraoperative consultations or frozen sections for central nervous system (CNS) tumors present a significant challenge for surgical pathologists because of their relative rarity and diversity. Yet, such lesions are encountered by every surgical pathologist, and a basic understanding of clinical, radiological and genetic information is critical to successfully evaluate CNS frozen sections. It is often beneficial to have a systematic approach or an algorithm, and to be aware of the common pitfalls and mimickers when dealing with these lesions. We propose such an algorithm in an effort to construct a sensible approach to CNS frozen sections that considers recent developments in the WHO CNS tumor classification. The algorithm was developed for surgical pathologists who are occasionally faced with making diagnosis of CNS tumors on frozen sections. To test the algorithm and its practicability, we selected a group of tumors among a total of 3288 consecutive intraoperative consultations performed at UCSF between 2013 and 2017. The selected cases represented lesions that may be encountered in everyday surgical pathology and constituted a fair reflection of the main group. The algorithm was used by three of the authors who did not have formal neuropathology training and had been in surgical pathology practice for at least 3 years. There was a very high level of concordance among the authors' diagnosis (interobserver concordance: 0.83-0.97-kappa value) using the algorithm with high intraobserver reliability (concordance 93%, p < 0.001). We suggest that an algorithmic approach is an effective means for the surgical pathologists, and may help reach diagnosis during frozen sections.

Urgent surgical management of congenital intracranial hemangiopericytoma in a preterm neonate.

Hemangiopericytoma is a rare mesenchymal tumor originating from capillary pericytes, known as Zimmermann pericytes. The adult form is not uncommon and generally malignant but tumor is found rarely in children. Here we describe an intracranial hemangiopericytoma in a preterm newborn whose had the tumor resected successfully shortly after birth.

Microcystic, elongated, and fragmented pattern of invasion in relation to histopathologic and clinical prognostic factors in endometrioid endometrial adenocarcinoma.

OBJECTIVE: To investigate the association of microcystic, elongated, and fragmented (MELF) pattern of invasion with prognostic factors in endometrioid endometrial adenocarcinoma (EEA). MATERIAL AND METHODS: Stained tissue sections from 83 cases of EEA operated by the same gynecologic oncologist were reviewed to identify cases showing MELF-type invasion in this retrospective study. The association of MELF pattern with age, tumor grade, depth of myometrial invasion, and presence of lymphovascular space invasion (LVSI) was analyzed. RESULTS: FIGO grade 2 and grade 1 tumors were evident in 53.0% and 38.6% of patients, respectively. Depth of myometrial invasion was <50% in 72.0% of patients, and LVSI was absent in 77.1%. MELF pattern was confirmed in 35 (42.2%) patients. Presence of MELF pattern was associated with significantly higher mean ± standard deviation age (62.9±6.9) years vs. 58.9±9.1 years, p=0.033), and found to be more likely in patients with high-grade tumor (FIGO grade III; 85.7% vs. 14.3%, p<0.001), deep (≥50%) myometrial invasion (78.3% vs. 21.7%, p<0.001), and presence of LVSI (94.7% vs. 5.3%, p<0.001) as compared with absence of MELF pattern. CONCLUSION: In conclusion, our findings revealed a high rate of MELF pattern among patients with EEA alongside the association of MELF pattern with poor prognostic factors such as high grade tumor, deep myometrial invasion, and LVSI.

Treatment of seborrheic keratosis in bilateral external auditory canal using fiber CO2 laser.

In this article, we report a 33-year-old female patient with lesions of bilateral external auditory canals who was treated using fiber CO2 laser without canaloplasty. Histopathological examination confirmed the diagnosis of irritated type seborrheic keratosis, which is rare in external auditory canal. Twelve months after the treatment, the patient showed no signs of recurrence.