Sebaceous carcinoma of the breast

Rare Breast Cancers Review

BACKGROUND/OBJECTIVES

Breast cancer is one of the most common malignancies in women, with rare subtypes presenting unique clinical challenges. This review provides a comprehensive analysis of rare breast cancers, including both epithelial and non-epithelial subtypes, and explores their epidemiology, pathology, prognosis, and treatment approaches.

METHODS

A systematic review was conducted focusing on recent advancements in the treatment of rare breast cancer subtypes. Articles were selected based on criteria emphasizing studies from the past five years, with older foundational studies included where necessary. The analysis incorporated molecular profiling, clinical trials, and advancements in targeted and immunotherapies, where possible.

RESULTS

Rare epithelial subtypes, such as tubular, mucinous, and medullary carcinomas, demonstrate distinct clinical and pathological features, with generally favorable prognoses compared to invasive ductal carcinoma (IDC). Non-epithelial cancers, including sarcomas and primary breast lymphomas, require individualized treatment due to aggressive behavior and poor prognosis in certain cases. Recent advancements in targeted therapies (e.g., HER2 inhibitors, PI3K inhibitors, and PARP inhibitors) and immunotherapies (e.g., PD-1 inhibitors) have shown promise in improving outcomes for specific molecularly characterized subtypes.

CONCLUSIONS

While the management of common breast cancers has become increasingly sophisticated, rare subtypes continue to pose challenges due to limited research and small patient populations. Advances in molecular profiling and next-generation sequencing are pivotal in identifying actionable mutations and expanding personalized treatment options. Future research should focus on clinical trials and collaborative efforts to refine treatment strategies and improve outcomes for these rare subtypes.

Invasive Breast Carcinoma With Sebaceous Morphologic Pattern Showing Lymph Node Macrometastasis: A Case Report

Invasive ductal carcinoma of no special type can present with various patterns. It is not possible to diagnose them through imaging alone. Microscopic examination is necessary to accurately identify and characterize them. The sebaceous pattern was historically considered a distinct subtype of breast carcinoma. However, the number of cases is relatively small and the prognosis has not been fully established. In this paper, we present a case of invasive ductal carcinoma with focal sebaceous features, which had a macrometastasis to the axillary lymph nodes showing the sebaceous morphology.

Specific cell differentiation in breast cancer: a basis for histological classification

Breast parenchyma progenitor cells show a high degree of phenotypic plasticity reflected in the wide range of morphology observed in benign and malignant breast tumours. Although there is evidence suggesting that all breast cancer (BC) arises from a common epithelial progenitor or stem cell located at the terminal duct lobular units (TDLUs), BC shows a broad spectrum of morphology with extensive variation in histological type and grade. This is related to the complexity of BC carcinogenesis including initial genetic changes in the cell of origin, subsequent genetic and epigenetic alterations and reprogramming that occur at various stages of BC development and the interplay with the surrounding microenvironment, factors which influence the process of differentiation. Differentiation in BC determines the morphology, which can be measured using histological grade and tumour type. Histological grade, which measures the similarity to the TDLUs, reflects the degree of differentiation whereas tumour type reflects the type of differentiation. Understanding BC phenotypic differentiation facilitates the accurate diagnosis and histological classification of BC with corresponding clinical implications in terms of disease behaviour, prognosis and management plans. In this review, we highlight the potential pathways that BC stem cells follow resulting in the development of different histological types of BC and how knowledge of these pathways impacts our ability to classify BC in diagnostic practice. We also discuss the role of cellular differentiation in producing metaplastic and neuroendocrine carcinomas of the breast and how the latter differ from their counterparts in other organs, with emphasis on clinical relevance.

Histology of Luminal Breast Cancer

Background

Invasive breast cancer (IBC) can be categorized into prognostic and predictive molecular subtypes (including luminal breast cancer) using gene expression profiling. Luminal IBC comprises a variety of histological subtypes with varying clinical and pathological features.

Summary

IBC of no special subtype is the most common histological subtype in general and likewise within luminal IBC. Classical invasive lobular breast cancer, typically clustering into luminal subgroup, is characterized by discohesive growth and loss of E-cadherin expression. Infrequent, morphologically distinct luminal IBC subtypes are tubular, invasive cribriform, mucinous, and invasive micropapillary carcinomas. Breast carcinoma with apocrine differentiation, with characteristic expression of androgen receptor (AR), often clusters into the luminal AR category. Rarely, neuroendocrine neoplasms of the breast can be seen. IBC of the male breast usually matches with the luminal subtype.

Key Messages

Independently from histological subtypes, invasive breast cancer (IBC) can be divided into molecular subtypes based on mRNA gene expression levels. Using this molecular subtyping, risk scores based on gene expression profiling (established for hormone receptor-positive, HER2-negative IBC), grading, and Ki-67 index, prognosis of patients with luminal breast cancer and response to chemotherapy can be predicted. In routine diagnostics, the expression of estrogen receptor (ER) and progesterone receptor (PR), HER2 status, and the proliferation rate (Ki-67) are used to determine a surrogate (molecular-like) subtype. Within luminal(-like) IBC, no special subtype and invasive lobular breast carcinoma are the most common histological subtypes. Other rare histological subtypes (e.g., tubular carcinoma) should be recognized due to their distinct clinical and pathological features.

Special type breast carcinoma: Sebaceous carcinoma of the breast; A case report and review of literature

Sebaceous carcinoma of the breast is an extremely rare tumor. To the best of our knowledge only 15 cases have been reported in literature. Herein, we report a case of sebaceous carcinoma of the breast and describe the histopathologic features of sebaceous carcinoma of the breast in an elderly female.

Sebaceous Carcinoma of the Breast: Fact or Fiction? A Case Report and a Review of the Literature

Introduction. Previously considered an exceedingly rare entity, sebaceous carcinoma of the breast is now regarded in the World Health Organization 2019 classification as a "special histopathological pattern" of invasive breast carcinoma of no special type. Case Description. In this article, we report the case of a fine needle aspiration cytology and the histopathological features of a breast carcinoma with clear-cut morphological features suggesting sebaceous differentiation, but showing no positive staining with the anti-adipophilin antibody. Conclusions. A morphologically clear-cut sebaceous differentiation is not invariably associated with adipophilin positivity; moreover, in breast carcinoma, adipophilin positivity does not automatically imply sebaceous differentiation. At present, immunomorphological evidence for the recognition of sebaceous carcinoma as a "special type" breast carcinoma subtype is too weak.

Sebaceous carcinoma of the breast predominantly characterized by intraductal growth: a case report

Background

Sebaceous carcinoma (SC) is frequently classified as periocular or extraocular. Extraocular SC is rare and mainly occurs in the head and neck, the major salivary glands, or oral mucosa. SC of the breast, lung, and ovary is particularly rare, and the few cases of SC of the breast predominantly exhibit intraductal growth.

Case presentation

A 47-year-old Japanese woman was referred to our hospital with accumulated polymorphic calcification in the left breast which was detected using mammography. Ultrasonography revealed an irregular 13-mm mass in the left breast, and analysis of a core needle biopsy revealed noninvasive ductal carcinoma. Total mastectomy and sentinel lymph node biopsy were performed. Histopathology demonstrated that carcinoma in situ (CIS) represented a significant lesion, and the cytoplasm of tumor cells was clear with numerous minute vacuoles. Immunohistochemical analysis demonstrated that most tumor cells expressed adipophilin. Together, these findings led to a diagnosis of SC, mainly comprising CIS.

Conclusions

We encountered a rare case of SC of the breast with predominant CIS.

Impact of surgery and adjuvant treatment on the outcome of extraocular sebaceous carcinoma: a systematic review and individual patient's data analysis of 206 cases

BACKGROUND

Extraocular sebaceous carcinoma (EOSC) is an aggressive malignancy of the sebaceous gland. Surgery is considered the cornerstone of treatment, but there is lack of clarity about extent and adjuvant treatment.

METHODS

We conducted a systematic review and analysis of individual patient data of all published cases of EOSC to look into demography, pattern of care, importance of type of surgery, and other adjuvant treatment and survival outcome. A search of PubMed and Google Scholar was done with the key words sebaceous carcinoma, extraocular sebaceous carcinoma, and Muir-Torre syndrome till December 2017. The data were compiled in an Excel chart and analyzed using SPSS IBM software.

RESULTS

Data of 206 patients were retrieved. Median age at presentation was 65 years (range: 11-96 years). Surgery was performed in all except 13 patients. Of these 13, eight were deemed inoperable for extensive disease, and five had metastatic disease. Median PFS and OS for the entire cohort were 84 months (95% CI: 10-158 months) and 92 months (95% CI: 59-126 months). Univariate analysis revealed significantly poor survival for patients with a metastatic disease, regional nodal metastasis, and those with Mohs micrographic or incomplete surgery.

CONCLUSION

EOSC is a disease of elderly patients with good prognosis. Complete surgery with regional lymph node dissection is standard treatment. The role of adjuvant radiotherapy is debatable but can be considered in patients with incomplete surgery or high-risk factors.

Caracterização anatomopatológica e imuno-histoquímica dos tumores das glândulas cutâneas em cães

RESUMO O presente estudo objetivou caracterizar os aspectos anatomopatológicos e imuno-histoquímicos dos tumores das glândulas cutâneas em cães. A caracterização morfológica seguiu a classificação atualizada da Organização Mundial de Saúde. Para a caracterização imuno-histoquímica, utilizaram-se anticorpos monoclonais primários anti-citoqueratina 14 (CK14), vimentina, p63, calponina, EGFR e Ki-67. Dos animais examinados, 66,67% (18/27) eram machos e 33,33% (9/27) fêmeas, 21 tinham raça definida e seis eram sem raça definida (SRD), com idade variando entre sete e 15 anos. Dos tumores caracterizados, 40,74% eram hepatoides (11/27), 29,63% sebáceos (8/27), 25,92% apócrinos (7/27) e 3,70% meibômio (1/27). Os tumores malignos representaram 55,56%, e os benignos 44,44%. Com esses resultados, foi possível demonstrar que os tumores das glândulas cutâneas em cães são frequentes, sem predileção por raça, sexo e com idade superior ou igual a sete anos. Os anticorpos CK 14, p63, vimentina e EGFR foram imunoexpressos nas células basais, células de diferenciação sebácea dos tumores hepatoides e de meibômio e células mioepiteliais. Entretanto, a vimentina e o EGFR não demonstraram imunomarcação para os tumores sebáceos. A calponina foi um bom marcador para as células mioepiteliais. O índice de Ki-67 foi mais acentuado nos tumores malignos em relação aos benignos. No entanto, estudos futuros utilizando maior número de casos se fazem necessários.

Sebaceous carcinoma of the breast in a patient with a pathogenic BRCA2 (886delGT) mutation - focus on histopathologic and immunohistochemical features

Sebaceous carcinoma of the breast (SCB) is a rare variant of ductal carcinoma arising within the mammary gland and containing at least 50% of malignant cells with sebaceous differentiation. Only 11 cases that adjust to the criteria delineated in the WHO classification have been published in the English literature, to the best of our knowledge. Here, we present the first SCB arising in the context of a deleterious BRCA2 mutation, focusing on the histopathologic and immunohistochemical features of this exceedingly rare tumor.

Sebaceous carcinoma of the breast: a case report

Background

Sebaceous carcinoma of the breast is a distinct variant of invasive ductal carcinoma. It is rare and only several cases have been reported.

Case presentation

An 80-year-old woman noted bloody discharge from her left nipple and palpated a lump in her left breast. Ultrasonography revealed a 19-mm mass in the left breast. Fine-needle aspiration suggested invasive ductal carcinoma. Partial mastectomy and sentinel lymph node biopsy were performed. On histological examination, the tumor revealed solid growth of small, round uniform cells with clear cytoplasm, partially intermingled with vacuolated cells indicative of sebaceous differentiation. The tumor cells contained abundant Sudan Black B-positive lipid droplets in the cytoplasm, and they were immunohistochemically positive for adipophilin. They were negative for estrogen receptor, progesterone receptor, and androgen receptor; positive for cytokeratin 7 and Ber-EP4; and partially positive for epithelial membrane antigen. Based on these findings, the patient was diagnosed with sebaceous carcinoma of the breast.

Conclusions

We diagnosed a rare case of sebaceous carcinoma of the breast.

A case of sebaceous carcinoma arising in a benign cystic teratoma of the ovary and review of the literature

Objective:

To present an extremely rare case of sebaceous carcinoma arising in a mature cystic teratoma of the ovary.

Clinical presentation and intervention:

A 66-year-old woman presented with abdominal discomfort and a pelvic mass. Abdominal and pelvic ultrasound, as well as CT scan, revealed a 27 cm complex right pelvic mass, which was diagnosed histologically as a sebaceous carcinoma arising in a mature cystic teratoma. The patient underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy, peritoneal washings, appendicectomy and infracolic omentectomy.

Conclusion:

This case adds to the rare reports in the literature of sebaceous carcinoma occurring in a mature cystic teratoma. The clinical behaviour and optimal management of this entity are not well established. The patient has been well for 32 months following surgery with no evidence of recurrent disease clinically.

Sebaceous metaplasia in a canine mammary gland non-infiltrative carcinoma with myoepithelial component

Sebaceous metaplasia in canine mammary tumors is a rare condition with only 1 case documented. The current study describes a case of sebaceous metaplasia in a mammary gland carcinoma of an 8-year-old intact, nulliparous female Poodle dog with a subcutaneous tumor located in the left fifth mammary gland. The lesion measured 0.7 cm × 0.5 cm × 0.6 cm in diameter, was firm, circumscribed, painless, non-haired, and non-ulcerated, and did not adhere to deep tissues. The cut surface was non-lobulated, non-encapsulated, whitish to gray, and opaque. Histological evaluation revealed 3 different populations of cells: the first was composed of columnar to cuboidal malignant epithelial cells arranged in intraductal papillary projections, the second of myoepithelial cells associated with a myxoid stroma, and the third presenting sebaceous metaplasia similar to those previously described in both human and veterinary medicine.

Mammary adenoma with sebaceous differentiation in a dog

The current report describes a complex canine mammary adenoma with a rare histological feature characterized by sebaceous differentiation of tumor cells. A 13-year-old, mixed-breed, intact female dog had mammary tumors on the right mammary chain. Histologically, one of the masses was composed of bilayered ductal structures with luminal epithelial cells together with basaloid or myoepithelial cell components. Within the tumor, there were a number of lobules and nests of large foamy cells associated with basaloid reserve-like cells similar to sebaceous gland. Squamous metaplasia was also seen within the tumor. Immunohistochemical staining indicated that the tumor cells with sebaceous differentiation were positive for cytokeratin (CK)14 and that the associated basaloid reserve-like cells were positive for p63. In contrast, other luminal epithelial tumor cells were positive for CK18 and CK19, but not for CK14 and p63. The myoepithelial cells were positive for α-smooth muscle actin and p63. The expression of p63 in both sebaceous basaloid reserve-like cells and myoepithelial cells, and their structural continuity within the tumor tissue, suggested a common origin of these 2 components.

Metaplastic Carcinoma of the Breast With Dominant Squamous and Sebaceous Differentiation in the Primary Tumor and Osteochondroid Metaplasia in a Distant Metastasis

Metaplastic breast carcinoma is an uncommon tumor that develops from conventional ductal mammary carcinoma, usually consisting of squamous and/or spindle cell components and/or mesenchymal elements. Although several morphological subtypes of metaplastic breast carcinoma are known, sebaceous metaplasia has not yet been described in this context. The authors report a case of an 84-year-old woman with a huge, ulcerated primary tumor in her left breast that had already been present for 10 years. Pulmonary and bone metastases and a tumor nodule in the contralateral breast were also detected at the time of admission. Left simple mastectomy was performed. Histological examination of the tumor revealed metaplastic carcinoma consisting of ductal carcinoma, which immunohistochemically exhibited a triple-negative immunoprofile, along with dominant areas of squamous and sebaceous differentiation. Adjuvant chemotherapy was subsequently given with partial regression of the systemic metastases. Seven months after surgery and diagnosis, a new, rapidly growing, large soft tissue metastatic tumor appeared in the intramuscular compartment of the patient’s right thigh, which was removed and histologically examined. Morphologically this metastatic tumor showed ductal adenocarcinoma along with areas of sebaceous differentiation and, in addition, osteochondroid metaplasia. Immunohistochemically, unlike the primary, this tumor expressed HER-2. The case is presented because of its rarity, and sebaceous differentiation is also proposed as a novel type of metaplasia in this context, expanding the spectrum of the histological patterns of metaplastic breast carcinoma. The literature concerning breast sebaceous lesions is reviewed, and the hypothetical biological mechanisms responsible for the tumor pathogenesis in this case are discussed.

Complex mammary adenoma with sebaceous differentiation in a dog

Sebaceous metaplasia arising within a complex adenoma of the left fourth mammary gland is described in a 9-year-old miniature pinscher bitch. Microscopically, the tumour was composed of tubular and ductular structures admixed with clusters of spindle-shaped, myoepithelial-like cells and units formed of well-differentiated sebocytes surrounded by basaloid cells. Abundant lipid droplets were identified within the latter population by Sudan III staining. Immunohistochemical expression of cytokeratin AE1/AE3 was detected in epithelial cells and in the cells with sebaceous differentiation.

Radiologic and pathologic findings in breast tumors with high signal intensity on T2-weighted MR images

Various histopathologic components in benign and malignant breast lesions may generate hyperintense signal at T2-weighted magnetic resonance (MR) imaging. A comparison of the specific histologic features found in breast lesions with a high-signal-intensity appearance on unenhanced T2-weighted turbo spin-echo MR images obtained without spectral fat suppression shows that this MR imaging characteristic is often suggestive of the differential diagnosis. Histopathologic features that may produce high signal intensity in breast lesions include extensive necrosis, a cystic or microcystic component, an adipose or sebaceous component, mucinous stroma, loose myxoid stroma, stromal edema, and hemorrhagic changes. A more nuanced understanding of the correlation between the MR imaging appearance and specific pathologic findings may help radiologists achieve earlier and more accurate differentiation among this group of breast lesions.

Mammary carcinoma with sebaceous differentiation in a dog

This report describes an invasive mammary carcinoma with a rare distinctive feature characterized by sebaceous differentiation of tumor cells. This tumor occurred in a 10-year-old female mixed breed dog. The patient had two masses in the left fifth mammary gland. Grossly, the masses were firm, whitish to light brown, and superficially ulcerated. On cut surface, they were multilobulated with foci of necrosis. Microscopically, the tumors were composed of two distinctive neoplastic components, intraductal papillary adenocarcinoma and sebaceous carcinoma. The regions of sebaceous tumor were clumped separately, contained well-developed sebaceous cells and keratinized epithelial cells, and were surrounded by few to several layers of basaloid cells. The cells with abundant foamy cytoplasm that resembled sebaceous cells were also found within the intraductal papillary-like nests of mammary carcinoma, providing evidence of sebaceous metaplasia. Sebaceous differentiation in a mammary gland tumor is possible, because skin appendages and ductal apparatus of the mammary gland share a common anlagen. This tumor had an aggressive behavior with lymphatic metastasis. Consequentially, the dog had a poor prognosis.

Sebaceous carcinoma of the breast: case report and review of the literature

Sebaceous differentiation has been described in only limited examples of benign and malignant epithelial lesions of the breast. We report a rare case of mammary sebaceous carcinoma to further delineate its morphologic features. Microscopically, the tumor, arising in the right mammary gland of a 63-year-old woman, was composed of well-defined solid sheets or lobules of atypical epithelial cells including many large pale or clear cells with often scalloped nuclei and coarsely vacuolated cytoplasm, in which abundant lipid droplets were identified with oil-red-O staining. Immunohistochemical expressions of cytokeratin, epithelial membrane antigen, and receptors of estrogen and progesterone were detected, whereas GCDFP-15, S-100 protein, vimentin, alpha-smooth muscle actin, p63, androgen receptor, and the HER2/neu protein were not expressed. Besides, a subset of the tumor cells co-expressed synaptophysin, neurofilament, and PGP9.5, suggesting neuroendocrine differentiation that is a hitherto undescribed phenomenon in the mammary tumors with sebaceous features. This case would expand the morphologic diversity of carcinoma of the breast.

Sebaceous carcinoma and the T-antigen

Carcinomas of sebaceous glands are uncommon. They are traditionally classified into ocular and extraocular sebaceous carcinomas (SC). Ocular SC tend to be more common and more aggressive than extraocular SC. However, the latter can occasionally follow a fatal course. Histologically, SC should be classified into 1) SC in situ; 2) SC, infiltrating, low-grade with or without pagetoid spread; 3) SC, infiltrating, high-grade, with or without pagetoid spread; and 4) SC with extraocular and extracutaneous involvement, including metastases. Immunohistochemistry plays a minor role in the diagnosis of SC. Thomsen-Friedenreich (T) antigen can be a helpful tool in differentiating SC (strong T-antigen reactivity in basaloid cells) from other mimicking neoplasms (basaloid cells are T-antigen negative). The histologic differential diagnosis, pathogenesis, and management of SC are reviewed.