Recurrent granulomatous mastitis associated with breast sparganosis: a case report

Granulomatous mastitis is an uncommon chronic inflammatory breast disease with diverse etiologies, including infectious causes.

Here, we report the case of a 74-year-old Thai woman with recurrent breast mastitis due to rare breast sparganosis. Four years after an initial diagnosis of granulomatous mastitis of unknown etiology, she presented with a new painless breast mass at a different site. Histopathological examination of a new lesion revealed a cestode worm surrounded by reactive lymphoid hyperplasia. Molecular identification using PCR targeting Cytochrome Oxidase subunit I (COI) gene highly suggested the causative species as Spirometra mansoni and retrospective PCR of the initial breast lesion was also positive for the same species. The patient underwent surgical excision followed by praziquantel therapy, without recurrence at 12-months of follow-up.

This case underscores the need to consider parasitic infection as a cause of granulomatous mastitis in endemic regions and highlights the value of molecular diagnostics when histopathology is inconclusive. Complete surgical excision remains the cornerstone of treatment, making an accurate diagnosis essential, as management differs from other forms of granulomatous mastitis.