Nodular hidradenoma of the breast: A case report with literature review. Indian J Surg. 2009;71:43-45. [PMID: 23133109 DOI: 10.1007/s12262-009-0010-y]

Clear cell hidradenoma of the breast with MAML2 gene rearrangement

Clear cell hidradenoma is a rare benign tumor of the breast, its origin and pathogenesis are controversial. We have experienced a case of breast clear cell hidradenoma with mastermind like transcriptional coactivator 2 (MAML2) gene rearrangement. The patient found a painless mass with a hard texture in the left breast areola without nipple discharge. Microscopically, the tumor was cystic and solid, locally arranged in a glandular structure, covered by single cuboidal cells; it was composed of clear cells, epidermoid cells, and basaloid cells; there were no necrosis or mitotic figures. Immunohistochemical staining showed that the tumor cells positively expressed low-molecular cytokeratin 7, low-molecular cytokeratins (Cam5.2), high-molecular cytokeratin 5/6, cytokeratin 14, CD117, and p63; and did not express calponin, and smooth muscle myosin heavy chain. The cuboidal cells were positive for SOX10 but negative for p63. Additionally, periodic acid-Schiff reaction showed purple-red granules in the tumor cytoplasm, but Alcian blue staining showed no blue mucus in the cytoplasm. The split signals of MAML2 gene were detected by fluorescence in situ hybridization. Subtle histological and immunophenotypical differences may help to distinguish breast clear cell hidradenoma from common breast tumors. Furthermore, the MAML2 gene rearrangement may be a molecular genetic characteristic of breast clear cell hidradenoma.

Genetic and Immunohistochemical Profiling of Mammary Hidradenoma and Comparison to Mucoepidermoid Carcinoma

Mucoepidermoid carcinoma (MEC) is exceedingly rare in the breast, with <45 cases reported in the literature. Although estrogen receptor/progesterone receptor/human epidermal growth factor 2 triple-negative, MEC is characterized as a special subtype of breast carcinoma with significantly better prognosis than conventional basal-type tumors. Cutaneous hidradenoma (HA) is considered a benign adnexal neoplasm showing histomorphologic overlap with MEC. Rare cases of HA have also been reported in the breast, but these are relatively uncharacterized. In this study, we examined the clinicopathologic, immunohistochemical (IHC), and genetic features of 8 breast HAs, in comparison to 3 mammary MECs. All cases were positive for MAML2 break-apart fluorescence in situ hybridization. Eight cases demonstrated a CRTC1::MAML2 fusion, and one MEC harbored a CRTC3::MAML2 fusion; the latter is a novel finding in the breast. Mutational burden was very low, with only one HA exhibiting a MAP3K1 pathogenic alteration. By IHC, both MEC and HA demonstrated cell type-dependent expression of high- and low-molecular-weight keratins and p63, as well as negative to low-positive estrogen receptor and androgen receptor. Smooth muscle myosin and calponin highlighted an in situ component in the 3 cases of MEC; expression of these myoepithelial markers was negative in HAs. Additional distinguishing characteristics included the growth pattern and tumor architecture, the presence of glandular/luminal cells in HA, and overall higher IHC expression of SOX10, S100 protein, MUC4, and mammaglobin in MEC. Morphologic findings were also compared to a series of 27 cutaneous nonmammary HAs. Mucinous and glandular/luminal cells were identified in significantly more mammary HAs than nonmammary lesions. The findings provide insight into the pathogenesis of MAML2-rearranged neoplasms of the breast, underscore the overlapping genetic features of MEC and HA, and highlight similarities to their extramammary counterparts.

Clear Cell Hidradenocarcinoma: a Rare Identity Difficult to Recognize - Case Report and Review of the Literature

Hidradenocarcinoma (HC) is a malignant and aggressive sweat gland tumour. It is a rare occurrence, accounting for about 6% of malignant eccrine cancers and less than 1% of all cutaneous neoplasms. It is a malignant tumor which can manifest itself in any area of the body, including the anterior surface of the trunk, the torso, scalp, face, and extremities. It is apparent that HC has a high propensity for lymphatic metastasis. The suggested treatment approach for HC implies making a wide surgical excision with negative margins. Nevertheless, such tumours are aggressive and recur locally in 50% of cases; they also produce metastases in 60% of cases. The overall five-year survival rate is 30%. Here, we present the case of a 68-year-old Caucasian male with unknown diagnosis of malignant neoplasm of inguinal cutaneous skin of sweat gland called hydrocarcinoma.

Clear Cell Hidradenoma of the Breast Diagnosed on a Core Needle Biopsy: A case report and review of the literature

Clear cell hidradenoma (CCH) is a tumour originating from the eccrine sweat glands. It usually presents in the limbs, axilla or trunk. CCH of the breast is rare and can present as a cystic lesion in the breast that can be easily misdiagnosed as malignancy. We report a 36-year-old female patient who presented at the Sultan Qaboos University Hospital Breast Clinic, Muscat, Oman, in 2018 with a lump in her left breast. Ultrasound examination reported a complex cystic lesion with a solid, vascular component. An ultrasound-guided core needle biopsy was suggestive of clear cell hidradenoma. Surgical excision was performed and histopathology confirmed the diagnosis of CCH of the breast. This is the first ever case of a diagnosis of CCH made using core needle biopsy. CCH can be challenging to diagnose; therefore, awareness of its histopathological and ultrasonographic features are essential to avoid misdiagnosis and over treatment.

Case Report and Literature Review of Nodular Hiradenoma, a Rare Adnexal Tumor That Mimics Breast Carcinoma, in a 20-Year-Old Woman

Nodular hidradenoma is an uncommon cutaneous adnexal tumor arising from sweat glands. In the skin, it usually presents as a solitary dermal nodule; excision is curative in most cases. In rare instances, it may present as a breast mass and can mimic breast carcinoma clinically and radiologically, causing diagnostic dilemmas for the treating physician and pathologist. Herein, we discuss a case of nodular hidradenoma in a 20-year-old Hispanic woman as a rapidly growing mass in the breast that mimicked breast carcinoma. We discuss the rare presentation of this uncommon tumor and the differential diagnosis of this entity, as well as the results of our literature review on the topic.

Malignant sweat gland tumor of breast arising in pre-existing benign tumor: A case report

BACKGROUND

Sweat glands belong to skin appendages. Sweat gland tumors are uncommon, especially when they occur as malignant tumors in the breast. We report a case of malignant sweat gland tumor of the breast, including imaging and pathological findings.

CASE SUMMARY

A 47-year-old woman visited our hospital with a non-tender palpable lesion in her left breast. The lesion had not shown changes for 10 years. However, it recently increased in size. Sonography showed a well circumscribed cystic lesion with internal debris and fluid-fluid level. Magnetic resonance imaging showed a well circumscribed oval mass with T1 hyper-intensity compared to muscle and T2 high signal intensity. There was a small enhancing mural component in the inner wall of the mass. The tumor was resected. Its pathologic result was a malignant transformation of benign sweat gland tumor such as hidradenoma. The lesion was treated with excision and radiation therapy. At 1-year follow up, there was no local recurrence or metastasis in the patient.

CONCLUSION

In the case of a rapid growing cystic mass in the nipple and subareola, it is necessary to distinguish it from a malignant sweat gland tumor.

Atypical Hidradenoma Mimicking Primary Mammary Carcinoma on Breast Fine-Needle Aspiration: A Case Report with Long-Term Follow-Up

BACKGROUND

Fine-needle aspiration (FNA) is well-established as an accurate technique for the diagnosis of palpable breast masses. While the differential diagnosis of such lesions usually focuses on benign or malignant mammary proliferations, a subset of breast neoplasms arises from skin and soft tissue. Skin adnexal neoplasms such as hidradenoma can pose a particular pitfall on breast FNA cytology (FNAC) as epithelial proliferations that are not of ductal or lobular origin.

CASE

A 59-year-old female presented with a superficial breast mass. FNAC revealed a hypercellular lesion with marked nuclear atypia that was highly suspicious for carcinoma. However, at partial mastectomy, the histological features of the tumor were consistent with atypical hidradenoma. Negativity for estrogen receptor (ER) and progesterone receptor (PR) confirmed the diagnosis. Eighteen years later, the patient remains free of recurrence or metastasis.

CONCLUSIONS

This report offers the first description of findings of atypical hidradenoma on FNAC. In the breast, its high cellularity and nuclear atypia can mimic a primary mammary carcinoma on FNAC. Although breast and skin adnexal tumors show a immunohistochemical overlap, negative ER and PR stains in a low-grade tumor can suggest a nonmammary lesion. Skin adnexal neoplasms should be considered in the differential diagnosis of superficial breast tumors.

Clear cell hidradenoma of breast mimicking atypical breast lesion: a diagnostic pitfall in breast cytology

Clear cell hidradenoma (CCH) is an uncommon skin adnexal tumor arising from eccrine glands. Although several kind of skin adnexal tumors arise in the breast tissue, CCH of the breast is an extremely rare entity. Failure to identify its cytomorphologic features and rarity of this tumor may lead to misdiagnosis on fine needle aspiration cytology. Hereby we report a case of 30-year-old female who presented with painless lump in left breast since 10 months. Fine needle aspiration cytology of lump yielded fluid material. On May-Grunwald-Giemsa stained smears, a possibility of atypical breast lesion was considered and patient was advised a biopsy examination. Final diagnosis of CCH was made on histopathologic examination. Awareness of cytomorphologic features of breast CCH will prevent misdiagnosis as malignant or atypical breast lesions and will allow for correct management of the patients.

Nodular hidradenoma of male breast: Cytohistological correlation

Nodular hidradenoma is an established entity as a skin adnexal tumor arising from eccrine sweat glands. A skin adnexal tumor located in the breast is unusual and is one of the differential diagnoses for subareolar breast nodules. With the exception of gynecomastia, other lesions of the male breast are not very common. The review of literature showed only 25 reported cases till date. The rarity of this neoplasm and failure to identify its morphologic features may lead to misdiagnosis. Being itself rare, cytological features of this lesion are hardly encountered in case reports. We report a case of an 18-year-old male who presented with a left breast lump and underwent fine needle aspiration and was diagnosed as having a benign skin adnexal tumor. Later it was confirmed by histopathology to be a nodular hidradenoma.