Secretory carcinoma was once used exclusively as a term for rare, slowly growing breast tumors without reference to their location in the breast. It is now termed mammary secretory carcinoma because secretory carcinoma has sometimes been used to name tumors which develop in non-breast tissues but have the microscopic appearance of, and a critical gene abnormality found in, mammary secretory carcinoma. This genetic abnormality is a balanced genetic translocation that forms a ETV6-NTRK3 fusion gene which appears involved in promoting the development and/or progression of all these tumors.[1][2]
The formerly termed secretory carcinomas include:
Mammary secretory carcinoma, also termed secretory carcinoma of the breast, is a slow growing breast cancer that develops in female adults and, in a significant percentage of cases, males and children.[3] While rare, it is the most common type of breast cancer that develops in children.[4] (Mammary secretory carcinoma, termed secretory carcinoma at the time, was first described in 1966.[5])
As of 2021, 26 cases of secretory carcinoma of the skin had been reported.[9][10] In a review of 25 cases, the skin tumors occurred in 16 females and 9 males aged 13 to 98 years (mean: 51.8 years). These tumors most common locations were the axilla (10 cases), neck (3), and lip (3 cases) with single cases occurring in other skin sites such as a cheek, eyelid, thigh, or skin at the base of a breast nipple. The tumors were treated primarily by surgical removal plus in some cases nearby lymph noderadiotherapy. Although these patients need to be followed for longer periods, at the times of their last follow-up reports, all of these patients' tumors had taken indolent courses without recurring or metastasizing to distant tissues.[11][9][10] However, in a recent report not included in the series of 25 cases, a 31-year-old female was diagnosed with an axillary secretory carcinoma of the skin and treated with surgical removal of the tumor and radiotherapy to nearby lymph nodes; 4 years later, the patient developed metastasizes in both lungs.[10] Most of these tumors consisted of cells that expressed the NTRK3-ETV6 fusion gene. (Secretory carcinoma in the skin was first described in 2009.[10])
Salivary gland–type carcinoma of the thyroid
Salivary gland–type carcinoma of the thyroid, also termed intrathyroidal mammary analog secretory carcinoma, has been reported in 12 cases in the English language.[12] In a review of 11 cases, salivary gland–type carcinomas of the thyroid were diagnosed in adult females (9 cases) and males (2 cases) with an average age 61.5 years (range: 36–74 years). These individuals presented with a thyroid mass with two individuals complaining of shortness of breath and one individual complaining of hoarseness. Their tumors' microscopic histopathology resembled that described in the pathology section of mammary secretory carcinoma and consisted of tumor cells that expressed the NTRK3-ETV6 fusion gene. All cases were treated by thyroidectomy (removal of the thyroid gland) plus radiotherapy in 6 cases and/or chemotherapy in 3 cases. Six of 10 individuals experienced local recurrences (n = 3) or one or more metastases (n = 3) after initial treatment; their tumors had invaded nearby normal thyroid tissues, trachea, mediastinum, and/or and cartilage and metastasized to the liver, lung, kidney, bone, and/or soft tissues. Salivary gland-type carcinoma of the thyroid appears to be a more aggressive disease than mammary secretory carcinoma or MASCSG.[2] (Salivary gland-type carcinoma of the thyroid was first described in 2015.[13])
Secretory carcinomas located in other sites
Tumors with the microscopic histopathology of secretory carcinomas and consisting of cells that express the NTRK3-ETV6 fusion gene have been reported to occur in the nasal cavity of a 51 year old (tumor size: 1.5×1.5×0.4 cm) and 62 (tumor size: 4×4×1.5) year old woman,[14] an ethmoid sinus of a 67-year-old female,[15] lung of a 62-year-old female (8.5 cm in largest dimension),[16] and vulva of a 51-year-old female.[17]
^Knaus ME, Grabowksi JE (August 2021). "Pediatric Breast Masses: An Overview of the Subtypes, Workup, Imaging, and Management". Advances in Pediatrics. 68: 195–209. doi:10.1016/j.yapd.2021.05.006. PMID34243852. S2CID235786044.
^Khalele BA (2017). "Systematic review of mammary analog secretory carcinoma of salivary glands at 7 years after description". Head & Neck. 39 (6): 1243–1248. doi:10.1002/hed.24755. PMID28370824. S2CID3073024.
^Skálová A, Vanecek T, Sima R, Laco J, Weinreb I, Perez-Ordonez B, Starek I, Geierova M, Simpson RH, Passador-Santos F, Ryska A, Leivo I, Kinkor Z, Michal M (2010). "Mammary analogue secretory carcinoma of salivary glands, containing the ETV6-NTRK3 fusion gene: a hitherto undescribed salivary gland tumor entity". The American Journal of Surgical Pathology. 34 (5): 599–608. doi:10.1097/PAS.0b013e3181d9efcc. PMID20410810. S2CID19924608.
^ abcdTaniguchi K, Yanai H, Kaji T, Kubo T, Ennishi D, Hirasawa A, Yoshino T (August 2021). "Secretory carcinoma of the skin with lymph node metastases and recurrence in both lungs: A case report". Journal of Cutaneous Pathology. 48 (8): 1069–1074. doi:10.1111/cup.14028. PMID33882152. S2CID233352244.
^Bishop JA, Taube JM, Su A, Binder SW, Kazakov DV, Michal M, Westra WH (January 2017). "Secretory Carcinoma of the Skin Harboring ETV6 Gene Fusions: A Cutaneous Analogue to Secretory Carcinomas of the Breast and Salivary Glands". The American Journal of Surgical Pathology. 41 (1): 62–66. doi:10.1097/PAS.0000000000000734. PMID27631515. S2CID23882212.
^Baloch ZW, Asa SL, Barletta JA, Ghossein RA, Juhlin CC, Jung CK, LiVolsi VA, Papotti MG, Sobrinho-Simões M, Tallini G, Mete O (March 2022). "Overview of the 2022 WHO Classification of Thyroid Neoplasms". Endocrine Pathology. 33 (1): 27–63. doi:10.1007/s12022-022-09707-3. PMID35288841. S2CID247440666.
^Baneckova M, Agaimy A, Andreasen S, Vanecek T, Steiner P, Slouka D, Svoboda T, Miesbauerova M, Michal M, Skálová A (June 2018). "Mammary Analog Secretory Carcinoma of the Nasal Cavity: Characterization of 2 Cases and Their Distinction From Other Low-grade Sinonasal Adenocarcinomas". The American Journal of Surgical Pathology. 42 (6): 735–743. doi:10.1097/PAS.0000000000001048. PMID29543674. S2CID3911820.
^Lurquin E, Jorissen M, Debiec-Rychter M, Hermans R, Hauben E (November 2015). "Mammary analogue secretory carcinoma of the sinus ethmoidalis". Histopathology. 67 (5): 749–51. doi:10.1111/his.12702. PMID25828788. S2CID1487884.
^Huang T, McHugh JB, Berry GJ, Myers JL (April 2018). "Primary mammary analogue secretory carcinoma of the lung: a case report". Human Pathology. 74: 109–113. doi:10.1016/j.humpath.2017.10.027. PMID29104113.
^Nguyen JK, Bridge JA, Joshi C, McKenney JK (May 2019). "Primary Mammary Analog Secretory Carcinoma (MASC) of the Vulva With ETV6-NTRK3 Fusion: A Case Report". International Journal of Gynecological Pathology. 38 (3): 283–287. doi:10.1097/PGP.0000000000000501. PMID29672325. S2CID5031074.