Rapid and unusual spread of basaloid squamous cell carcinoma of the maxillary sinus. Basaloid squamous cell carcinoma is a variant of epidermoid carcinoma with a morphology consisting of both basaloid and squamous cell components. It is a high-grade tumour with a propensity for nodal and systemic metastases. In this report, we present the aggressive course of a basaloid squamous cell carcinoma of the maxillary sinus in a 28-year-old patient who died only four months after the initial diagnosis. We describe the unusual spread of the disease to the scalp, pancreas, kidney, adrenal gland, ovaries, lungs and bone marrow.