Imaging the butterfly: A rare presentation of bilateral primary small lymphocytic lymphoma in the infratemporal fossa with incidental detection.

The infratemporal fossa is a deep anatomical space rarely involved in lymphoproliferative disorders. Small lymphocytic lymphoma (SLL), a low-grade subtype of non-Hodgkin lymphoma (NHL), is exceptionally rare in this region, with only a few cases reported in the literature. We report the first known case of a 48-year-old patient with a primary, bilateral, butterfly-shaped SLL of the infratemporal fossae, discovered incidentally during imaging after a road traffic accident. Clinical signs of infratemporal fossa involvement are often nonspecific or absent, particularly in indolent forms like SLL. Diagnosis relies on imaging, histopathology, and immunohistochemistry. Treatment typically involves chemotherapy, especially purine analogues, while surgery is usually limited to diagnostic biopsy. Long-term follow-up with laboratory and radiologic monitoring is essential due to the risk of recurrence or systemic involvement, including the spleen, liver, and lymph nodes.