Search

Background: Accurate and precise diagnosis is central to treating central nervous system (CNS) tumors, yet tissue diagnosis is often a neglected focus in low- and middle-income countries (LMICs). Since 2016, the WHO classification of CNS tumors has increasingly incorporated molecular biomarkers into the diagnosis of CNS tumors. While this shift to precision diagnostics promises a high degree of diagnostic accuracy and prognostic precision, it has also resulted in increasing divergence in diagnostic and management practices between LMICs and high-income countries (HICs). Pathologists and laboratory professionals in LMICs lack the proper training and tools to join the molecular diagnostic revolution. We describe the impact of a 7-year long twinning program between Canada and Pakistan on pathology services. Methods: During the study period, 141 challenging cases of pediatric CNS tumors initially diagnosed at Aga Khan University Hospital (AKUH), Karachi, were sent to the Hospital for Sick Children in Toronto, Canada (SickKids), for a second opinion. Each case received histologic review and often immunohistochemical staining and relevant molecular testing. A monthly multidisciplinary online tumor board (MDTB) was conducted to discuss the results with pathologists from both institutions in attendance. Results: Diagnostic discordance was seen in 30 cases. Expert review provided subclassification for 53 cases most notably for diffuse gliomas and medulloblastoma. Poorly differentiated tumors benefited the most from second review, mainly because of the resolving power of specialized immunohistochemical stains, NanoString, and targeted gene panel next-generation sequencing. Collaboration with expert neuropathologists led to validation of over half a dozen immunostains at AKUH facilitating diagnosis of CNS tumors. Conclusions: LMIC-HIC Institutional twinning provides much-needed training and mentorship to pathologists and can help in infrastructure development by adopting and validating new immunohistochemical stains. Persistent unresolved cases indicate that molecular techniques are indispensable in for diagnosis in a minority of cases. The development of affordable alternative molecular techniques may help with these histologically unresolved cases. [ABSTRACT FROM AUTHOR]

Spindle epithelial tumor with thymus-like differentiation (SETTLE) is a rare malignant thyroid tumor showing thymic or related branchial pouch differentiation. The tumors are composed predominantly of spindle cells along with focal epithelial component and ductular formations. SETTLE occurs in young patients, with indolent growth and a tendency to develop delayed blood-borne metastases. We herein report two cases of SETTLE with a follow-up period of 64 months and 30 months, respectively.

Sarcomatoid carcinoma of prostate is an extremely rare but aggressive neoplasm. It is generally associated with a poor prognosis. About 100 cases have so far been reported in the English literature. We report the case of a 64-year-old male with a very rapidly progressive disease that ultimately involved the whole lower urinary tract and rectum. The management of this case along with etio-pathogenesis and literature review is discussed. [ABSTRACT FROM AUTHOR]