Incidental mastocytosis in a lady with Cowden syndrome: a case report

Cowden syndrome (CS) is an extremely uncommon hereditary cancer syndrome which results from a mutation in one of the tumour suppressor gene, known as PTEN. This, in turn, leads to widespread manifestation of harmatomas in multiple organs including skin and gastrointestinal tract. CS is also associated with an increased risk of cancer development namely in the breast, thyroid and endometrium. Mast cells have been linked to cancer development and in mammary tumours, it has been postulated to result in invasiveness. At present, existing case reports documented the presence of mast cells solely in soft tissues harmatomas in patients with Cowden syndrome (PHOST). We report a case of locally advanced breast cancer diagnosed in a young 37 -year -old lady of Asian descent with CS. Upon screening the contralateral breast, she was found to have atypical ductal hyperplasia (ADH) following stereotactic biopsy and subsequent prophylactic mastectomy showed low grade ductal carcinoma in situ (DCIS) situated away from the biopsy site. Incidental mastocytosis was discovered in both mastectomy specimens. Appropriate adjuvant anticancer treatment was prescribed. As she did not display any symptoms of systemic mastocytosis, no treatment was needed. This is the first reported case of mastocytosis in patients afflicted with CS and synchronous breast cancer. More research can be done to examine this relationship between mast cells and v induced breast cancer and to evaluate for differences in tumour biology and clinical outcomes as compared to nonhereditary mammary cancers.