Case report: Unique ultrasound feature of thyroid metastases in occult breast cancer

Abstract

Occult breast cancer is an uncommon type of breast cancer. Metastases of occult breast cancer to other tissues are rather rare. We present a rare case of thyroid metastases in a 46-year-old woman who underwent occult breast cancer. The first ultrasound (US) examination of the thyroid showed that the left lobe was enlarged but had normal thyroid function. At first, this case was misdiagnosed as thyroiditis based on the thyroid US features. However, the cytological and histological results showed that nests of the neoplastic cells were found. Further immunohistochemistry results confirmed that these neoplasms were derived from breast tissue. Analysis using the successive US scans revealed that the sizes and echo of the thyroid repeatedly changed after the radiotherapy and chemotherapy treatment. To our knowledge, this is the first reported case of occult breast carcinoma presenting with thyroid metastases. This case can easily be misdiagnosed as thyroiditis due to the metastasis area not manifesting as regular suspicious nodules or diffused punctate calcifications.

Case report: Uncommon multiple metastases from occult breast cancer revealed by 68Ga-DOTATATE PET/CT

“…According to previous literature and case reports, the most common sites of pathological diagnosis or metastasis were the axilla, bone, and orbit. Meanwhile, some uncommon sites had also been reported, including gastrointestinal tract, liver, lung, thyroid, and brain (8)(9)(10). OBC patients with distant metastatic disease have a much worse prognosis, with a 5-year survival of 14.3% (8).…”

Thyroid Metastasis from Primary Breast Cancer

“…The vast majority of TMs are metachronous [ 20 ], detected after a mean time of 2.3 years in head and neck cancers [ 10 , 21 ], a mean time of 9.4 years in renal cell carcinoma [ 22 ], and even after 21 years in intestinal neuroendocrine tumors [ 23 ]. In our literature review, we found 38 papers published between 2000 and the end of January 2023 that satisfied our search criteria, consisting of 58 cases of TM that originated from BC [ 5 , 9 , 11 , 17 , 18 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ]. We summarized the cases in Table 2 .…”