Korean J Pathol.  2007 Dec;41(6):412-415.

Metastatic Medullary Carcinoma of Thyroid to Breast; A Case Initially Diagnosed as Primary Invasive Lobular Carcinoma: A Case Report

• Lee Y
• An J
• Kim CH
• Yeom BW
• Choi JS
• Chae YS

Abstract

Metastasis to the breast from medullary carcinoma of the thyroid is extremely rare. We report a case of metastatic medullary carcinoma of the thyroid which presented as multiple breast masses with ipsilateral axillary lymphadenopathy in a 48-year-old woman. Six years ago, she underwent total thyroidectomy and neck dissection because of palpable neck masses, with a diagnosis of medullary thyroid carcinoma. Histological features of breast masses showed single- file or linear-cord arrangements, with plasmacytoid appearance, and the initial diagnosis was invasive lobular carcinoma. She underwent modified radical mastectomy. The tumor cells were diffusely positive for E-cadherin, calcitonin and thyroid transcription factor-1 (TTF-1) and were metastatic medullary carcinoma of thyroid. In the patients with a history of medullary carcinoma of the thyroid, a careful examination is necessary for a breast mass composed of solid and cord-like clusters of small round to ovoid cells with plasmacytoid appearance. Immunohistochemical staining for E-cadherin, calcitonin and TTF-1 could be helpful for differential diagnosis.

Keyword

Medullary carcinoma; Thyroid; Breast; Metastasis; Invasive lobular carcinoma

MeSH Terms

Breast*
Cadherins
Calcitonin
Carcinoma, Lobular*
Carcinoma, Medullary*
Diagnosis
Diagnosis, Differential
Female
Humans
Lymphatic Diseases
Mastectomy, Modified Radical
Middle Aged
Neck
Neck Dissection
Neoplasm Metastasis
Thyroid Gland*
Thyroid Neoplasms
Thyroidectomy
Cadherins
Calcitonin