Pictorial Review of Post COVID-19 Acute Invasive Fungal Sinusitis: Clinical Radiologists' Perspective

Acute invasive fungal sinusitis (AIFS) is a rapidly progressive infection predominantly seen in immunocompromised patients. There is an increasing incidence of AIFS post COVID-19 infection. Yet, there is sparse literature regarding spectrum of cross-sectional imaging findings (CT and MRI) in these patients, which is prudent for appropriate timely surgical intervention. This study aims to highlight spectrum of imaging findings in patients with post-COVID-19 AIFS integrating the clinical details from presentation to follow-up. We retrospectively reviewed the demographics, clinical details and radiological imaging of 31 histopathological proven cases of post COVID-19 AIFS. MR and CT images of these patients were retrieved from the PACS and analysed. 90-day follow-up of these patients was obtained. Statistical analysis was performed using descriptive statistics. Cross-sectional imaging showed nasal cavity involvement in all patients, bilateral in (15, 48%) cases; predominant involvement of maxillary (31, 100%) followed by ethmoid sinuses (29, 93.5%) was seen. MR showed patchy/complete loss of normal mucosal enhancement in the turbinates and sinuses as predominant imaging finding. Maxillary sinus walls erosions were seen in 28 cases (90%). Rhino-orbital and rhino-orbito-cerebral mycosis was seen in 24 (77%) and 14 (45%) respectively. Optic nerve-sheath complex was involved in 15 (48%) cases. Cerebral involvement was seen in form of meningeal enhancement, cerebritis, ischemic changes, cavernous sinus and intracranial arterial thrombosis and aneurysms. Comprehensive knowledge of imaging features of AIFS and recognition of extent of their spread allows radiologists to play pivotal role in alerting the clinician for appropriate therapy to avoid protracted and fatal outcome.

Retinal histopathology of an XLRP carrier with a mutation in the RPGR exon ORF15

X-linked retinitis pigmentosa comprises the severe forms of RP, with early onset of night blindness, rapid constriction of visual fields and eventual loss of central acuity. Of the five distinct XLRP loci identified on the X chromosome, mutations have been found only in the RP2 and RPGR genes. Of these, mutations in RPGR are more common, particularly in a mutational hot spot that was identified in the newly discovered exon ORF15. We report on an extended family with a microdeletion in RPGR exon ORF15 and the retinal histopathology of a female carrier of this mutation. We found a 1bp deletion at position 632 in exon ORF15 in affected members of family XLRP-319. This mutation alters the reading frame of the predicted RPGR protein, resulting in a premature stop codon. The mutation segregated with disease in three generations of the family and was associated with severe early onset retinal disease in affected men. The retina from a 75 year old carrier female donor had slight photoreceptor loss in the less diseased areas. More severe atrophy with retinal pigment epithelium (RPE) migration was present in areas of the mid- and far periphery. By immunocytochemistry, loss of rhodopsin labelling in rods was found in the areas of focal atrophy and loss of uniform cone spacing was apparent even in well preserved regions. Small multifocal areas of outer retinal degeneration were present in the better preserved regions of the eye. In these foci, rod and cone loss did not coincide. The dissociation of rod and cone degeneration in areas of focal disease is consistent with random X-inactivation early in embryonic development and the occurrence of distinct patterns of radial (rod) and tangential (cone) dispersion during clonal expansion early in photoreceptor differentiation.