Adenoid cystic carcinoma of the breast: Experience at a tertiary care centre of Northern India

Solid basaloid adenoid cystic carcinoma of the breast: A high-grade triple negative breast carcinoma which rarely responds to neoadjuvant chemotherapy

Solid basaloid adenoid cystic carcinoma of the breast (SB-AdCC) is an exceedingly rare but important entity that warrants clear separation from classic AdCC (C-AdCC) for optimal treatment. This case series retrospectively reviewed the diagnosis and treatment of 20 breast AdCCs. While four breast pathologists reached consensus on the diagnosis of all C-AdCCs, there was considerable disagreement when diagnosing pure SB-AdCCs. The morphology and immunohistochemical profiles of SB-AdCC closely resemble those of basaloid triple-negative breast carcinoma (TNBC). Molecular profiling of SB-AdCC revealed frequent mutations in the Notch pathway and alterations in chromatin modifiers, such as CREBBP and KMT2D. MYB-NFIB fusion was rare and detected in only 2 of 9 (22.2 %) SB-AdCCs. Axillary lymph node metastasis was present in 2 of 10 patients with SB-AdCC at the time of surgery. During a median follow-up of 27 months, one patient with SB-AdCC developed axillary recurrence. Moreover, 6 of 12 (50.0 %) patients with SB-AdCC developed distant metastases. Of the three patients who underwent neoadjuvant chemotherapy for SB-AdCC, one achieved near-complete pathological response, while the remaining two had minimal response. In conclusion, this series underscores the aggressive clinical course of SB-AdCC, similar to conventional TNBC. Pathologically, SB-AdCC also closely mimics conventional TNBC. It is imperative for pathologists to clearly indicate C-AdCC or SB-AdCC or give a percentage of each component to ensure appropriate treatment strategies and avoid both over-treatment and under-treatment.

Solid basal adenoid cystic carcinoma of the breast: A case report and literature review

RATIONALE

Adenoid cystic carcinoma (AdCC) is a rare malignancy of the breast with a low Ki-67 index and good prognosis. Owing to the rarity of breast AdCC, the misdiagnosis rate is as high as 50%, and there is no consensus or recognized guidelines for the treatment of this disease. Therefore, it is necessary to conduct a detailed clinical and pathological analysis in combination with a literature review to improve our understanding, diagnosis, and treatment of the disease.

METHODS

A 68-year-old woman sought medical attention due to a recently increasing mass in the breast. The left breast mass was 1.3 cm × 1 cm in size. We analyzed the morphology, immunohistochemistry, and molecular characteristics of the tumor removed by surgery, and reviewed relevant literature.

DIAGNOSES

Solid basal AdCC of the breast.

INTERVENTIONS

We performed biopsy, immunohistochemistry and molecular testing on surgical resection specimens.

OUTCOMES

Combining morphological and immunohistochemical features, it is consistent with solid basal AdCC of the breast, and Fish detected MYB gene break.

LESSONS

Due to the high misdiagnosis rate of AdCC, accurate histopathological diagnosis is particularly important. At present, breast conserving surgery and local tumor resection are mainly used for the treatment of breast AdCC, and postoperative adjuvant radiotherapy is feasible.

Adenoid Cystic Carcinoma of the Breast: Radiologic-Pathologic Correlation

Adenoid cystic carcinoma (ACC) is an uncommon malignancy occurring most frequently in the salivary glands. Breast ACC is rare. Pain is common at the site of ACC; otherwise, presentation is similar to other primary breast cancers. Adenoid cystic carcinomas classically lack calcifications; the imaging manifestations of ACC are otherwise highly variable, likely related to multiple pathologic growth patterns. While ACC in other regions of the body tends to be more aggressive, ACC involving the breast typically has less aggressive biologic characteristics. Classic-type breast ACC has a lower tendency to recur locally with radiation, metastasize to regional lymph nodes, and spread to other parts of the body. Perineural spread of disease can be seen but is not common. The rarer solid basaloid-type has a higher tendency for local or distant spread and recurrence. Although ACC is usually triple receptor-negative (estrogen receptor, progesterone receptor, human epidermal growth factor-2 receptor), the indolent nature of this tumor dictates its management. With classic-type ACC, the inclusion of axillary surgery has no consensus and the use of chemotherapy or hormonal therapy is rare. Axillary nodal surgery and chemotherapy are often included in management of the more aggressive solid basaloid-type. An understanding of the breast imaging, histopathology, and clinical course is key for appropriate treatment and follow-up of ACC.

Breast adenoid cystic carcinoma: a report of seven cases and literature review

Background

Primary adenoid cystic carcinoma (ACC) of breast is rarely seen clinically. It is a special subtype of triple-negative breast cancer characterized by low expression of Ki-67, low malignant potential, slow progression and favorable prognosis. To date, treatment for this disease is controversial and no consensus is reached. We analyzed clinical manifestations and pathological characteristics of seven primary breast ACC cases and reported in combination with literature review to promote understanding, diagnosis and treatment of this disease.

Case presentation

We collected seven breast ACC cases pathologically diagnosed and treated in Department of breast surgery of the First Affiliated Hospital of China Medical University from January 2015 to December 2018. We organized and summarized the clinical, imaging, pathological and prognostic information and performed statistical analysis. The median age was 60 years (ranging from 54 to 64 years). Tumors of all patients were detected by immunohistochemistry. Molecular types were mostly triple negative (4/7), and Ki-67 expression was low (5/7). Lymph node metastases were absent in all patients received axillary lymph node surgery. Median follow-up time was 39 months (ranging from 25 to 68 months). There was no occurrence of relapse, distant metastasis or death.

Conclusion

Breast ACC is accompanied with favorable diagnosis, which is different from typical triple-negative breast cancer. Accurate diagnosis of ACC is particularly important.

Special Histologic Type and Rare Breast Tumors - Diagnostic Review and Clinico-Pathological Implications

Breast cancer is the most common malignant tumor in females. While most carcinomas are categorized as invasive carcinoma, no special type (NST), a diverse group of tumors with distinct pathologic and clinical features is also recognized, ranging in incidence from relatively more common to rare. So-called "special histologic type" tumors display more than 90% of a specific, distinctive histologic pattern, while a spectrum of tumors more often encountered in the salivary gland may also arise in the breast. Metaplastic carcinomas can present diagnostic challenges. Some uncommon tumors harbor pathognomonic genetic alterations. This article provides an overview of the key diagnostic points and differential diagnoses for this group of disparate lesions, as well as the salient clinical characteristics of each entity.

Evaluation of efficacy of chemotherapy for mucinous carcinoma: a surveillance, epidemiology, and end results cohort study

Background

In this study, we investigated the impact of chemotherapy on breast cancer-specific survival (BCSS) in patients with mucinous carcinoma using the surveillance, epidemiology, and end results (SEER) database.

Methods

A large-scale SEER-based retrospective analysis was conducted; 13,329 patients with mucinous carcinoma from 1994 to 2014 were identified. Clinicopathological characteristics were compared using the chi-square test. BCSS curves were generated using the Kaplan-Meier method. The prognostic significance of all demographic and clinicopathological characteristics and treatment patterns were calculated using univariate and multivariate regression analyses.

Results

Mucinous carcinoma was demonstrated to be less aggressive than invasive ductal carcinoma and predicted a better prognosis in the Kaplan-Meier analysis (hazard ratios = 0.336, 95% confidence interval: 0.308-0.368, p < 0.001). Univariate and multivariate analyses revealed that chemotherapy did not provide any additional benefit for patients with mucinous carcinoma. Predictors for receiving chemotherapy were younger age, estrogen receptor-negative, progesterone receptor-negative, and human epidermal growth factor receptor 2-positive status, higher grade, larger tumor size, lymph node involvement, radiation reception, and mastectomy. Further subgroup analysis verified that regardless of the hormone receptor (HR) and lymph node (LN) status, patients did not benefit from chemotherapy.

Conclusion

Our study showed that patients with HR+/LN- mucinous carcinoma did not benefit from chemotherapy and that chemotherapy could not improve the survival of all subtypes of mucinous carcinoma based on large-scale SEER data. These results support that patients with mucinous carcinoma could be exempt from chemotherapy. Additional research is needed to further evaluate the impact of adjuvant treatments, particularly in patients with favorable histology.

Special subtypes with favorable prognosis in breast cancer: A registry-based cohort study and network meta-analysis

BACKGROUND

We aimed to explore whether cribriform and adenoid cystic carcinoma had comparable prognoses to mucinous, tubular and papillary carcinoma, which were long recognized as favorable histologies by NCCN guidelines.

METHODS

A retrospective analysis based on the Surveillance, Epidemiology, and End Results Study (SEER) database (1994-2014) was conducted. The prognostic significance of all clinicopathological factors was calculated using univariate and multivariate analyses. A systematic review based on PubMed and network meta-analysis was conducted.

RESULTS

From the SEER database, the histologic subtypes of breast cancer (tubular, cribriform, adenoid cystic, mucinous, and papillary) were sorted by overall survival (OS) (94.4%, 91.6%, 90.8%, 87.6%, and 84.2%, respectively) and tubular, cribriform, mucinous, papillary, and adenoid cystic carcinoma by breast cancer-specific survival (BCSS) (99.4%, 98.4%, 97.7%, 95.2%, and 94.9%, respectively). A network meta-analysis combining 11 studies (886,649 patients) was conducted, which demonstrated consistent outcomes. SEER-based analyses revealed that, among the favorable subtypes, systemic chemotherapy did not improve OS or BCSS in hormone receptor-positive, node-negative patients, validating that these subtypes are generally associated with excellent outcomes, for which systemic chemotherapy may not be warranted.

CONCLUSIONS

Our data are consistent with guidelines suggesting that the mucinous, tubular, and papillary subtypes of breast cancer have favorable histologies. SEER data and meta-analysis supports this favorable category to include adenoid cystic and cribriform carcinoma, whose OS and BCSS outcomes are comparable to the former three. These findings add to the body of data, suggesting that patients with these histologic subtypes confer excellent prognosis, which may guide optimal therapeutic management strategies.

Concurrent breast adenoid cystic carcinoma and primary squamous cell carcinoma: report of a rare case with single institutional case reviews

Background

Adenoid cystic carcinoma and primary squamous cell carcinoma are both rare breast neoplasms, which possess drastically different morphological and molecular features as well as distinguishing clinical behaviors and prognosis.

Case presentation

In this report, we described a rare case in which concurrent adenoid cystic carcinoma and keratinizing squamous cell carcinoma were diagnosed in contralateral breasts in an 85 year-old female patient. The patient had a history of adenoid cystic carcinoma diagnosed 11 years ago, which was treated by partial mastectomy followed by whole breast radiation. The recurrent carcinoma on the same side of the breast was small in size but appeared to involve an intraductal papilloma. Also, a newly occurred large cystic mass was identified on the contralateral breast, which histologically presented as a keratinizing squamous cell carcinoma with no glandular differentiation. No in situ or invasive carcinoma was identified in the overlying skin of the lesion, and no malignancy in a second site was found by PET-CT. Therefore, this lesion was mostly likely a primary squamous cell carcinoma of the breast.

Conclusion

The concurrence of two such rare neoplasms was likely an incidental finding or was therapy-related. However, more mechanistic studies are needed in order to understand whether predisposing genetic alterations exist in this rare case. Besides, cases of both breast adenoid cystic carcinoma and carcinoma with predominant squamous differentiation diagnosed in our institution were reviewed, which help to better characterize their clinicopathological features.