“Secretory” Carcinoma of the Skin Mimicking Secretory Carcinoma of the Breast: Case Report and Literature Review

Abstract

Secretory carcinoma is a unique kind of adenocarcinoma. It has distinct histological features and a special genetic change, that is, t (12; 15) (p13; q25) translocation which leads to the expression of the ETV6-NTRK3 fusion gene. Secretory carcinoma has been found to occur both in the breast and salivary gland. Here the authors present a case of 22-year-old woman with a unique cutaneous neoplasm located at the axilla. The tumor was characterized histologically with the formation of round to ovoid microcysts and papillary structure, which was similar to the secretory carcinoma of the breast and salivary gland. Furthermore, the gene sequence analysis of reverse-transcription polymerase chain reaction products demonstrated the expression of the ETV6-NTRK3 fusion gene. To the authors' knowledge, this is the first case of secretory carcinoma from the skin which has the same genetic change as those from the breast and salivary gland. Local excision was performed on this patient. She had been followed up for nearly 1 year. No recurrence or metastasis was found yet.

Primary cutaneous secretory carcinoma: A previously overlooked low‐grade sweat gland carcinoma

“…Mild nuclear pleomorphism and rare mitotic figures, as in our case, may be noted, as well as perineural invasion . Immunohistochemically, tumor cells are positive for S100, mammaglobin and CK7 . (Table ) Other markers, usually positive although not consistently, have been reported (epidermal growth factor, CAM5.2, CK19, EMA, mucin 1, mucin 4, gross cystic disease fluid protein 15).…”

“…ETV6‐NTRK3 is demonstrable in up to 83% of cases, usually by FISH . Regarding prognosis, this neoplasm seems to behave as a low‐grade sweat carcinoma as in the 8 cases reported with a mean follow up of 43 months (6‐144 months), no patient presented node involvement or metastasis . Most of the cases were treated with surgical excision and only one sentinel lymph node biopsy was performed and was negative…”

“…Twelve cases of primary cutaneous secretory carcinoma (PCSC) have been published; 9 of them showed the ETV6‐NTRK3 translocation and an additional case had a heterozygous deletion of ETV6 in 25% of cells (Table ) . These cutaneous tumors are related to secretory breast carcinoma (SBC) and mammary analogue secretory carcinoma (MASC) from the salivary glands, with all sharing a balanced chromosomal translocation of t(12;15)(p13;q25) that leads to ETV6‐NTRK3 gene fusion.…”

“…PCSC affects females more frequently than males (8:5) with a mean age at diagnosis of 42.3 years (age range from 13 to 71 years), most common location is the axilla (7 cases), but it can affect the neck, cheek, forearm, flank and groin. ETV6‐NTRK3 is demonstrable in up to 83% of cases, usually by FISH .…”

“…PCSC affects females more frequently than males (8:5) with a mean age at diagnosis of 42.3 years (age range from 13 to 71 years), most common location is the axilla (7 cases), but it can affect the neck, cheek, forearm, flank and groin. ETV6‐NTRK3 is demonstrable in up to 83% of cases, usually by FISH . Regarding prognosis, this neoplasm seems to behave as a low‐grade sweat carcinoma as in the 8 cases reported with a mean follow up of 43 months (6‐144 months), no patient presented node involvement or metastasis .…”