Infiltrating syringomatous adenoma of the nipple: clinical presentation and literature review

Syringomatous tumor of the nipple: a case report

Syringomatous tumor of the nipple is a benign, locally infiltrative tumor. There are reports in the literature of tumor recurrence in cases of incomplete excision. Clinical and mammographic findings in syringomatous tumors are like those of breast carcinoma and the pathologist has a fundamental role in final tumor diagnosis. Therefore, the aim of this study was to report a case of syringoma located in the areolar region. A 33-year-old woman reported that she had noticed a nodule in her left areolar region 4 years previously (February 2019). A breast ultrasound was performed, detecting intraparenchymatous breast cysts. Surgical resection of the nodule was indicated although it was not performed. Two years later, in August 2021, the patient underwent a mastopexy with prosthesis inclusion. Histopathology study of the surgical specimen revealed a syringomatous tumor with positive margins. Thirteen (13) months after diagnosis (September 3, 2021 - October 16, 2022), the patient is doing well and receives clinical follow-up.

Multimodality Imaging of Benign and Malignant Diseases of the Nipple-Areolar Complex

The nipple-areolar complex (NAC), a unique anatomic structure of the breast, encompasses the terminal intramammary ducts and skin appendages. Several benign and malignant diseases can arise within the NAC. As several conditions have overlapping symptoms and imaging findings, understanding the distinctive nipple anatomy, as well as the clinical and imaging features of each NAC disease process, is essential. A multimodality imaging approach is optimal in the presence or absence of clinical symptoms. The authors review the ductal anatomy and anomalies, including congenital abnormalities and nipple retraction. They then discuss the causes of nipple discharge and highlight best practices for the imaging workup of pathologic nipple discharge, a common condition that can pose a diagnostic challenge and may be the presenting symptom of breast cancer. The imaging modalities used to evaluate and differentiate benign conditions (eg, dermatologic conditions, epidermal inclusion cyst, mammary ductal ectasia, periductal mastitis, and nonpuerperal abscess), benign tumors (eg, papilloma, nipple adenoma, and syringomatous tumor of the nipple), and malignant conditions (eg, breast cancer and Paget disease of the breast) are reviewed. Breast MRI is the current preferred imaging modality used to evaluate for NAC involvement by breast cancer and select suitable candidates for nipple-sparing mastectomy. Different biopsy techniques (US -guided biopsy and stereotactic biopsy) for sampling NAC masses and calcifications are described. This multimodality imaging approach ensures an accurate diagnosis, enabling optimal clinical management and patient outcomes. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Unraveling the Mysteries of Perineural Invasion in Benign and Malignant Conditions

Perineural invasion (PNI) is defined as the dissemination of neoplastic cells within the perineural space. PNI can be a strong indicator of malignancy and is linked to poor prognosis and adverse outcomes in various malignant neoplasms; nevertheless, it can also be seen in benign pathologic conditions. In this review article, we discuss various signaling pathways and neurotrophic factors implicated in the development and progression of PNI. We also describe the methodology, benefits, and limitations of different in vitro, ex vivo, and in vivo models of PNI. The spectrum of presentation for PNI can range from diffuse spread within large nerves ("named" nerves) all the way through localized spread into unnamed microscopic nerves. Therefore, the clinical significance of PNI is related to its extent rather than its mere presence or absence. In this article, we discuss the guidelines for the identification and quantification of PNI in different malignant neoplasms based on the College of American Pathologists (CAP) and World Health Organization (WHO) recommendations. We also describe benign pathologic conditions and neoplasms demonstrating PNI and potential mimics of PNI. Finally, we explore avenues for the future development of targeted therapy options via modulation of signaling pathways involved in PNI.

Asymptomatic syringomatous adenoma of the nipple: A rare nipple neoplasm

Syringomatous adenoma of the nipple is a very rare benign tumor, with radiographic and clinical characteristics that are difficult to differentiate from malignant tumors. Less than 60 cases have been identified thus far and most studies have not included radiographic findings. As such, the neoplasm requires more characterization within the literature. The usual clinical presentation of syringomatous adenoma of the nipple is symptomatic with a solitary, unilateral nipple mass within the subareolar region which may be tender and/or painful and may cause nipple inversion or discharge. We present a case of a 43-year-old woman that is unique, as the patient was asymptomatic and only presented following standard screening mammography. Moreover, we offer further characterization of the neoplasm through documented imaging and histologic findings.

Syringomatous Adenoma of the Nipple in a Male Breast: A Case Report With a Brief Review of Literature and Histomorphological Approach to Diagnosis

Syringomatous adenoma of the nipple (SAN) is a benign and locally infiltrative lesion possibly arising from the sweat gland ducts in the nipple-areolar region. This rare lesion has been reported in the female breast; however, reports on the male breast are extremely rare. Although benign, SAN has a high risk of recurrence. The clinical presentation and histomorphological features often mimic a malignancy. Hence, an awareness of this lesion is required to make a correct diagnosis. In this report, we describe the histomorphological features of SAN in a male breast.

Multimodality approach to the nipple-areolar complex: a pictorial review and diagnostic algorithm

The anatomic and histologic characteristics of the nipple-areolar complex make this breast region special. The nipple-areolar complex can be affected by abnormal development and a wide spectrum of pathological conditions, many of which have unspecific clinical and radiological presentations that can present a challenge for radiologists. The nipple-areolar complex requires a specific imaging workup in which a multimodal approach is essential. Radiologists need to know the different imaging modalities used to study the nipple-areolar complex, as well as their advantages and limitations. It is essential to get acquainted with the acquisition technique for each modality and the spectrum of findings for the different conditions. This review describes and illustrates a combined clinical and radiological approach to evaluate the nipple-areolar complex, emphasizing the findings for the normal morphology, developmental abnormalities, and the most common benign and malignant diseases that can affect this region. We also present a diagnostic algorithm that enables a rapid, practical approach to diagnosing condition involving the nipple-areolar complex.

Small Glandular Proliferations of the Breast With Absent or Attenuated Myoepithelial Reactivity by Immunohistochemistry: A Review Focusing on the Differential Diagnosis and Interpretative Pitfalls

CONTEXT

-Small glandular proliferations of the breast encompass a variety of benign, atypical, and malignant lesions that show some overlapping morphologic features. Myoepithelial stains are frequently used in the workup of these lesions in order to rule out or establish a diagnosis of invasive carcinoma. Some benign lesions show absent or diminished myoepithelial staining, and may represent an interpretative pitfall, particularly in small core biopsy samples.

OBJECTIVE

-To review small glandular proliferations of the breast that show absent or diminished staining with myoepithelial immunohistochemical markers.

DATA SOURCES

-The study comprised a review of published literature and clinical case material.

CONCLUSIONS

-The interpretation of myoepithelial stains in small glandular proliferations of the breast can, on some occasions, represent a challenge in diagnosing these lesions. Recognition of the key histopathologic features and immunohistochemical staining patterns of the entities in the differential diagnosis is crucial in their workup.

Syringomatous adenoma of the nipple: a case report

Introduction

Syringomatous adenoma of the nipple is a very rare benign tumor. To the best of our knowledge, there are no reports of a syringomatous adenoma of the nipple metastasizing, although these tumors are known to infiltrate locally and to recur if not totally resected.

Case presentation

Our patient was a 41-year-old Japanese woman who complained of stiffness of her right nipple with abnormal discharge. Local resection of the tumor was performed. The pathological diagnosis was syringomatous adenoma of the nipple, and the resection margin was found to be positive. Accordingly, additional resection was recommended, but our patient did not allow another operation. After 1.5 years of careful follow-up, no local recurrence or distant metastasis has been observed.

Conclusion

The optimal initial management of syringomatous adenoma of the nipple demands complete resection with histologically negative margins. However, from a cosmetic viewpoint, nipple-sparing resection could represent an alternative option for the treatment of syringomatous adenoma of the nipple.

Infiltrating syringomatous adenoma of the nipple: Sonographic and mammographic features with pathologic correlation

We report the case of a 39-year-old woman complaining of painless unilateral nipple enlargement for 3 weeks. She had no family history of breast cancer. Clinical examination revealed left nipple enlargement without pain, erythema, or skin changes m no associated palpable breast or axillary masses. Ultrasound showed several bright foci in the left nipple suggestive of microcalcifications. Neither solid nor cystic masses were detected. The mammogram performed subsequently confirmed the presence of multiple pleomorphic microcalcifications within the nipple. Wedge biopsy showed a syringomatous adenoma. Wide local excision of the nipple was performed. The postoperative course was uneventful.

Low-grade adenosquamous carcinoma of the breast with diverse expression patterns of myoepithelial cell markers on immunohistochemistry: a case study

This paper reports a case of low-grade adenosquamous carcinoma (LGASC) arising in a 69-year-old woman, who presented with a 1-cm palpable mass on her right breast. Core needle biopsy diagnosed the mass as a fibroadenoma. After six months, the mass increased in size, and the patient received subsequent mammotome excision. On microscopic examination, bland-looking small glands were infiltrating into the fibrotic stroma with lymphocytic infiltrates at the periphery. Hematoxylin and eosin staining revealed relatively easily detectable myoepithelial cells along the outside in each of the glandular structures with variable degrees of squamous metaplasia. Based on histologic features, the patient was diagnosed with LGASC. LGASC is a rare variant of metaplastic carcinoma, which is characterized by a favorable prognosis. Due to the bland cytology and presence of myoepithelial cells, LGASC can be misdiagnosed as benign lesion. Additionally, inconsistent expression of myoepithelial markers could aid the diagnosis of LGASC.

Low-grade adenosquamous carcinoma of the breast

Low-grade adenosquamous carcinoma is a rare and unique form of invasive mammary carcinoma. Though it is categorised as a variant of metaplastic carcinoma, it differs from its counterparts in this heterogeneous category by its relative clinical indolence, also reflected histologically in its low-grade cytomorphology. Descriptions of such a tumour were reported as early as 1912. However, low-grade adenosquamous carcinoma was only formally recognised in 1987 with the publication of Rosen and Ernsberger's landmark paper. Since then, several case reports and larger series have reaffirmed the clinicopathological characteristics of this unusual and uncommon tumour. Due to its rarity, however, many aspects of low-grade adenosquamous carcinoma, including its immunohistochemical and genetic profiles, remain unclear. This paper reviews the literature on this entity from 1987 to date, summarising its clinical and pathological features, and highlighting the diagnostic challenges it poses.

Nipple adenoma arising from axillary accessory breast: a case report

Nipple adenoma is a relatively rare benign breast neoplasm, and cases of the disease arising from the axillary accessory breast have very seldom been reported in the English literature. We report a case of nipple adenoma arising from axillary accessory breast including clinical and pathological findings. An 82-year-old woman presented with the complaint of a small painful mass in the right axilla. Physical examination confirmed a well-defined eczematous crusted mass that was 8 mm in size. The diagnosis of nipple adenoma was made from an excisional specimen on the basis of characteristic histological findings. Microscopic structural features included a compact proliferation of small tubules lined by epithelial and myoepithelial cells, and the merging of glandular epithelial cells of the adenoma into squamous epithelial cells in the superficial epidermal layer. Because clinically nipple adenoma may resemble Paget’s disease and pathologically can be misinterpreted as tubular carcinoma, the correct identification of nipple adenoma is an important factor in the differential diagnosis for axillary tumor neoplasms.

Small Glandular Proliferations of the Breast

This article discusses the most common small glandular proliferations, namely sclerosing lesions (sclerosing adenosis and radial scar), tubular carcinoma, and epithelial displacement after needle core biopsy, as well as less common entities, such as low-grade adenosquamous carcinoma, microglandular adenosis, and syringomatous adenoma. Due to significant morphologic overlap, these entities are easily mistaken for one another. The similarities and differences among these lesions in their clinicopathologic features, radiologic findings, and immunohistochemical profiles are emphasizesd.

Immunohistochemical staining characteristics of low-grade adenosquamous carcinoma of the breast

BACKGROUND

Low-grade adenosquamous carcinoma (LGASC) is an uncommon variant of metaplastic carcinomas of the breast. The immunohistochemical profile of this entity has not been well characterized and is likely because of its seemingly inconsistent staining patterns when commonly used immunohistochemical stains are employed. We set out to further elucidate the immunohistochemical profile of this uncommon entity in a sizable cohort of patients.

MATERIALS AND METHODS

Thirty cases of LGASC were identified in our files. Commonly used immunohistochemical stains such as myoepithelial and cytokeratin markers used to evaluate a small glandular proliferation in the breast (the differential diagnosis of which includes LGASC) were utilized. The pattern and location of immunoreactivity were recorded in each case. Results were compared for staining trends.

RESULTS

All cases of LGASC demonstrated variable staining in both lesional glands and stromal cells for myoepithelial (p63, smooth muscle myosin, smooth muscle actin, CD10, calponin) and cytokeratin (CK AE1/3, CK5/6, CK7, CK 34βE12, Cam 5.2) markers. Within a single case, circumferential staining using myoepithelial markers was complete, discontinuous, and absent in over a third of the studied cases. A minority of cases showed either complete circumferential staining (or complete absence) by any single immunohistochemical stain. Lamellar staining of stromal cells surrounding glands was best highlighted using smooth muscle myosin heavy chain or calponin. Using cytokeratin stains, core staining (luminal glandular cells demonstrating distinctly stronger staining intensity than the basally located cells in the same gland) was observed in approximately half of the studied cases. These lesional stromal cells were negative for all cytokeratins, with the exception of 1, which was focally positive for 1 cytokeratin immunostain (CK7) while being negative for 3 others.

CONCLUSIONS

LGASC consistently stains in an inconsistent manner using commonly used immunohistochemical stains. In addition, we found lamellar staining and core staining using myoepithelial and cytokeratin stains, respectively, to be distinctive and therefore diagnostically valuable.

Synchronous bilateral infiltrating syringomatous adenoma of the breast

Infiltrating syringomatous breast adenoma is an uncommon mammary neoplasm composed of angulated glandular structures with a variable amount of epidermoid differentiation which proliferate in a background of dense collagenous stroma. The patient presented with bilateral hardness and oedema of the nipples. Ultrasound and mammography revealed microcalcifications in retromammilary regions of both nipples. Histological examination of the resected specimens showed angulated glands and solid cords, lined by an inner layer of epithelial cells and an outer layer of myoepithelial cells, immersed in desmoplastic stroma. Within the solid cords reminiscent of squamous cells, occasionally aggregated in keratinizing cysts were found. To the best of our knowledge this is the first described case of bilateral infiltrating syringomatous breast adenoma with synchronous presentation. Infiltrating syringomatous adenoma is a rare lesion. A finding of infiltrating syringomatous adenoma in one breast should prompt careful examination of the opposite breast with adequate follow-up.

Origin and differentiation of breast nipple syringoma

Similarities in morphology and in glandular and squamous differentiation patterns amongst syringomas of the breast nipple and of the skin suggest a common nature, but the origin of nipple syringoma remains undefined. Using triple immunofluorescence analysis, we found that cells immunopositive for basal keratins K5 and 14 undergo differentiation into glandular and squamous cell lineages. Both tumour types expressed K10, indicative of squamous lineage, but there were specific differences in their glandular lineage. In contrast to the breast nipple syringoma, which expressed glandular keratins K8/18/19, syringoma of the skin only expressed the glandular keratin K19. Therefore, syringomas of the breast nipple and of the skin resemble glandular lineages of the breast nipple duct or eccrine duct epithelium, respectively. From these results we conclude that K5/14-positive cells of the breast nipple ducts are the putative cells of origin for syringomas of the nipple, which highlights the organotypic glandular differentiation potential.