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

Primary Cutaneous Secretory Carcinoma: A Case Report and Literature Review

Cutaneous secretory carcinomas (CSCs) are primary neoplasms of the skin that have been just recently described in the literature through case reports and series. In this case, a cutaneous lesion was found on the left temporal region of an 83-year-old male. He was referred to plastic surgery for complete excision, with negative margins confirmed by pathology. Histology, immunostaining, and genetic testing showed characteristics confirming the diagnosis of CSC and were supported by the information present in the current literature. Our patient showed no evidence of nodal disease or recurrence during regular follow-ups. Given the rarity of CSCs, we aim to present our experience regarding the diagnosis, pathological analysis, and management of our patient as well as summarize the present literature to further open avenues of research.

Secretory carcinoma of the breast limited to the dermis: Cutaneous or breast primary?

We offer a case of a 22-year-old woman who presented with a painless breast mass. Physical examination of the breast was unrevealing other than a palpable mass in close proximity to the nipple areolar region. No lymphadenopathy was noticed in the axilla or supraclavicular region. Sonographic assessment was performed and the findings were classified as Breast Imaging Reporting and Data System category 4. Because of the proximity of the mass to the skin surface, an excisional biopsy was performed. Final pathology disclosed a 5-mm invasive carcinoma. On pathologic examination, histopathologic and immunophenotypes supported the diagnosis of secretory carcinoma; however, whether the origin was from the breast parenchyma or skin tissue was not clearly discernable. Therefore, the patient was scheduled for sentinel lymph node biopsy with plans for axillary dissection if positive. While the overall prognosis for secretory carcinoma is good, with a low chance of metastasis, any ambiguity in breast mass diagnosis should be discussed in a multidisciplinary tumor board and should be treated aggressively particularly in younger patients.

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Apocrine and Eccrine Differentiation

Adnexal tumors of the skin are a rare group of benign and malignant neoplasms that exhibit morphological differentiation toward one or more of the adnexal epithelium types present in normal skin. Tumors deriving from apocrine or eccrine glands are highly heterogeneous and represent various histological entities. Macroscopic and dermatoscopic features of these tumors are unspecific; therefore, a specialized pathological examination is required to correctly diagnose patients. Limited treatment guidelines of adnexal tumor cases are available; thus, therapy is still challenging. Patients should be referred to high-volume skin cancer centers to receive an appropriate multidisciplinary treatment, affecting their outcome. The purpose of this review is to summarize currently available data on pathogenesis, diagnosis, and treatment approach for apocrine and eccrine tumors.

Secretory carcinoma of the skin with lymph node metastases and recurrence in both lungs: A case report

Secretory carcinoma of the skin is an extremely rare adnexal tumor, histopathologically identical to homologous lesions in the salivary glands and breast tissue. Although this tumor was previously reported as indolent, we report a case of secretory carcinoma of the skin with metastases and recurrence. The patient, a 31-year-old women, had a subcutaneous mass in the right axilla. The resected specimen contained a circumscribed mass, with proliferating tumor cells that exhibited prominent nucleoli. They exhibited glandular and papillary growth patterns and there were amphophilic secretions in the glands. Immunohistochemically, the tumor cells were positive for mammaglobin and S100. The tumor was surrounded by sweat glands and there was no mammary glandular tissue, suggesting that it was derived from axillary sweat glands. Accordingly, we made a diagnosis of secretory carcinoma of the skin. Four years after the operation, there were metastases in both lungs. The resected specimen revealed a tumor identical to that of the original skin tumor. Next-generation sequencing-based multiplex gene assay performed on the metastatic tissue revealed an ETV6-NTRK3 fusion gene. This is a rare case report of secretory carcinoma of the skin with lymph node metastases and recurrence in both lungs.

Secretory Carcinoma of the Skin: Report of 6 Cases, Including a Case With a Novel NFIX-PKN1 Translocation

Secretory carcinoma of the skin is a rare adnexal carcinoma, which is morphologically and immunohistochemically identical to secretory carcinoma of the breast and is associated with the presence of t (12;15) translocation, resulting in the ETV6-NTRK3 gene fusion. Nineteen cases of primary cutaneous secretory carcinoma have been previously published in the literature. In this study, we describe 6 new cases of secretory carcinoma of the skin. The study group consisted of 5 female patients and 1 male patient, ranging in age from 57 to 98 years (mean: 74.2, median: 74). Locations included the axilla (2), neck, eyelid, thigh, and nipple base, each one. Microscopically, all but 1 tumor were well circumscribed and nonencapsulated and exhibited characteristic abundant secretions within the microcystic and tubular spaces comprised by bland oval, round to cuboidal neoplastic cells. In addition, solid areas and focal pseudopapillae were seen, and, in 1 case, a focal mucinous component with small lakes of mucin containing small tumor nests or tubules of the neoplastic cells was present. The remaining neoplasm was mostly solid and papillary, with only few characteristic lumina containing secretions. Immunohistochemically, all cases expressed S-100 protein, mammaglobin, STAT5, GATA3, and NTRK. ETV6-NTRK3 gene fusion was detected in 5 cases, whereas, in the remaining tumor, a novel NFIX-PKN1 gene fusion was found.

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

INTRODUCTION

Twelve cases of primary cutaneous secretory carcinoma (PCSC) have been published, 9 showing ETV6-NTRK3 translocation, a characteristic finding shared with secretory breast carcinoma and mammary analogue secretory carcinoma.

CASE REPORT

A 34-year-old female presented a solitary nodule on the right groin. Biopsy revealed a secretory carcinoma staining positive with CK7, CAM5.2, mammaglobulin and S100 and negative with GATA3, CK20, podoplanin, calponin and CDX2. ETV6-NTRK3 was demonstrated by Fluorescence in situ hybridization (FISH).

DISCUSSION

PCSC is a rare neoplasm, described in the skin in 2009, that affects more frequently females with a mean age of 42.3 years and it is most commonly located in axilla. Histopathologically, these tumor cells are characterized by bubbly eosinophilic secretions diastase-resistant and bland nuclei and they are arranged in various growth patterns, including microcystic, tubular, solid and papillary. S100, mammoglobin and CK7 are usually positive. We review the main histopathological features to rule out histopathologic mimics such as breast metastasis, salivary tumors, cribriform carcinoma and primary cutaneous adenoid cystic carcinoma. GATA3 negative staining, as in our case, can help to rule out breast metastasis. Moreover, long-term benign follow up (144 months) in this case as well as follow-up data on outcomes from literature review support that PCSC is a low-grade sweat gland carcinoma.

ETV6 rearrangement in a case of mammary analogue secretory carcinoma of the skin

Mammary analog secretory carcinoma of salivary glands is a relatively recently recognized entity that harbors the ETV6-NTRK3 fusion transcript. To date, only rare cases of mammary analog secretory carcinoma of the skin have been reported. A 57-year-old man presented with a 6.0 cm cystic mass in the axilla, involving the dermis and superficial subcutis. Microscopically, the tumor exhibited nodular aggregation of tubular and microcystic structures embedded in the dense fibrotic and hyalinized stroma. Characteristic 'colloid-like' eosinophilic secretory material was present within intraluminal spaces. Tumor cells were largely characterized by vesicular nuclei with inconspicuous nucleoli and pink vacuolated cytoplasm. With respect to immunohistochemistry, tumor cells were intensely positive for AE1/AE3, Cam 5.2, and CK7, whereas Ber-EP4 and CEA were completely negative. A dual color break-apart fluorescence in situ hybridization probe identified rearrangement of the ETV6 gene locus on chromosome 12. The patient is alive with no evidence of recurrent disease or metastasis 3 years after the initial surgery. In conclusion, we report a rare example of mammary analog secretory carcinoma of the skin with ETV6 rearrangement. Awareness of this unique cutaneous tumor and subsequent reporting of additional cases is necessary for better characterization of its completely clinicopathologic spectrum.