ABSTRACT
Background The cavernous sinus is a complex space composed of extradural venous plexus within dural folds. Several important structures like the carotid artery, cranial nerves, and sympathetic nerve fibers traverse through this space. Radiological diagnosis may not be definitive and in the context of discordance between clinical and neuroimaging diagnosis, histopathological evaluation becomes essential for diagnosis and management. Literature on the pathological spectrum of lesions is scarce as, with a shift in the treatment paradigm, most small lesions of cavernous sinus are treated with radiosurgery. However, surgical management still plays a role for larger lesions and in radiologically ambiguous cases for planning the definitive management. Materials and Methods We retrospectively reviewed all surgically resected lesions of the cavernous sinus over the last two decades (1998-2019). The clinical presentation, neuroimaging features, and histopathological findings were reviewed. Lesions extending from sella and other adjacent areas were excluded. Results Thirty-eight cases of isolated cavernous sinus mass lesions were diagnosed over the last two decades (1998-2019). Cavernous hemangiomas (19 cases, 50%) constituted the most frequent pathology, followed by aspergilloma, meningioma, schwannoma, metastatic adenocarcinoma, chondrosarcoma, and chordoma. Overall, 29.4% (10/34) could not be accurately diagnosed on neuroimaging. Of these, four cases of cavernous hemangiomas were mistaken for either meningioma (three cases) or schwannoma (one case). Neither chordoma nor chondrosarcoma was suspected. Conclusion This is the first study in literature, enumerating the pathological and imaging spectrum of surgically resected cavernous sinus lesions. Cavernous hemangiomas, metastases and chordomas, and chondrosarcoma posed the greatest difficulty in diagnosis on neuroimaging and the reasons for the same are analyzed. In the context of clinical and neuroimaging discordance in diagnosis, pathological characterization becomes essential for appropriate and timely management.
ABSTRACT
Infections of the central nervous system (CNS) presenting as space-occupying lesions are not uncommon, particularly in developing countries. Most often, infective organisms gain entry into the CNS through the hematogenous route, seed the parenchyma, and cause tissue destruction. Subsequently, some form mass lesions in a manner similar to neoplastic growths. The commonality in pathogenesis and pathology between infective agents and neoplastic cells underlies the similarities in their presentations. Although neoplasms are the common considerations in the presence of enhancing lesions with perilesional edema and mass effect on neuroimaging, nonneoplastic conditions-in particular, infectious lesions--can have similar imaging characteristics. The widening spectrum of opportunistic and newly recognized pathogens has added to the difficulties. Biopsy diagnosis is mandatory for neoplasms, both for confirmation of diagnosis as well as grading, but most infectious lesions are managed conservatively if the diagnosis is established by noninvasive means. This review discusses some of the common infectious lesions that mimic CNS neoplasms, with emphasis on pyogenic, tuberculous, and fungal lesions as well as parasitic and viral infections that present as intracranial space-occupying lesions. The data of infective lesions that mimicked intracranial neoplasms, from our institute, over the last 5 years, are also presented. Awareness of the pathogenetic basis of tissue injury and host response, resulting in the spectrum of clinical and imaging patterns as well as a high index of clinical suspicion, are essential for accurate diagnosis, to ensure appropriate management.