From breast mass to paralysis: lymphocytic mastitis as the sentinel manifestation of Sjögren’s syndrome

Sjögren's syndrome is a systemic autoimmune disease classically characterized by sicca symptoms; however, extra glandular manifestations may precede glandular involvement and, in rare cases, present as life threatening emergencies. We report a middle-aged patient who presented with acute flaccid paralysis due to severe hypokalaemia secondary to distal renal tubular acidosis, requiring intensive care admission. Notably, the patient had undergone breast excision two years earlier for a painful breast mass, with histopathology highly suggestive of lymphocytic mastitis, which was misdiagnosed and treated as a breast abscess. Subsequent immunological evaluation confirmed primary Sjögren's syndrome. Prompt electrolyte correction and immunosuppressive therapy resulted in complete neurological recovery. LEARNING POINTS: Sjögren's syndrome may initially present with rare extra glandular manifestations, preceding classical sicca symptoms and leading to significant diagnostic delay.Lymphocytic mastitis can represent an early autoimmune manifestation of Sjögren's syndrome and may closely mimic infectious or malignant breast disease.Distal renal tubular acidosis is the most frequent renal manifestation of Sjögren's syndrome and may result in life-threatening hypokalemia and acute flaccid paralysis.