Paranasal sinus cancer claimed the #10 position for ACF abnormalities as a malignant tumor arising from paranasal sinus epithelium comprising the most common malignant anterior skull base tumor. Our Classic Clue section starts us thinking about an older male woodworker with a moderately enhancing mass destroying the skull base and adjacent paranasal sinus habitually having its epicenter near a paranasal sinus. Incidence: Approximately 1 per 1,000,000. Diagnostic Delay: As early symptoms are often ignored by both patients and doctors, patients perpetually present for imaging at advanced stages. Even patients presenting for imaging at early stages sometimes have their studies interpreted by less experienced radiologists who fail to fathom the early tumor signs. Clinical Issues address extension into the nasal cavity, orbit, oral cavity, and pterygoid muscle. Pertinent plain film, nuclear medicine, angiographic, CT, and MRI features are described including T1, T2, T1Gd, DWI, ADC, and STIR. 18F FDG PET/CT has high sensitivity and moderate specificity and seems superior to conventional CT and MR imaging for finding residual/recurrent tumor. Multiple representative MRI images are provided for perusal. Differential Diagnosis examines multiple heavy hitters which sometimes show similar imaging findings. Treatment and Prognosis discusses surgery, chemotherapy, and radiotherapy with expected outcomes.