Idiopathic granulomatus lobular mastitis. A forgotten clinical diagnosis

To review clinicopathological features of all cases diagnosed as idiopathic granulomatous lobular mastitis (IGLM) in our hospital and compare them with other data from the Kingdom of Saudi Arabia.

Reports of all breast specimens received in histopathology laboratory in Qatif Central Hospital, Kingdom of Saudi Arabia over a 14 year period (1988 through to 2002) were collected and those diagnosed as IGLM were selected for analysis of both pathological material and clinical data.

Eleven patients representing 1.6% of all breast specimens were diagnosed as IGLM. The mean age was 35 years (range 25-50). Both breasts were equally affected. The most frequent presenting symptom was a breast mass of 2-22 weeks duration. The most common clinical diagnosis was chronic abscess (5 patients). Relation to pregnancy, lactation or oral contraceptives pills was elicited in 4 patients. Recurrence at different time intervals occurred in 3 patients. Microscopically there was an evident granulomatous inflammation mostly in lobular distribution. Ductal inflammation with epithelial changes was noted in most cases. Staining and cultures were negative for both mycobacterium and fungal organisms.

Granulomatous mastitis is not unheard of and clinicians should keep it in their list of differential diagnosis of breast lumps so appropriate handling of breast specimens including microbiological studies can be pursued. Utility of fine needle aspiration biopsy as a diagnostic tool is to be considered.