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

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.

Cylindroma of the breast with CYLD gene mutation: a case report and review of the literature

BACKGROUND

Cylindroma of the breast is a rare benign neoplasm. Since its first description in 2001, 20 cases have been reported in the literature.

METHODS AND RESULTS

We report another case of this rare tumor in a 60-year-old woman with demonstration of the underlying molecular alteration. Histologically, the tumor showed the typical "jigsaw" pattern of a dual population of cells with a triple-negative phenotype. The pathognomonic mutation of the CYLD gene mutation was detected by whole exome sequencing. Cylindromas show morphological overlap with the solid-basaloid variant of adenoid cystic carcinoma, which renders this differential diagnosis difficult. However, distinction of these two lesions is of outmost importance, since cylindromas, in contrast to solid-basaloid variant of adenoid cystic carcinoma, behave in an entirely benign fashion.

CONCLUSIONS

Careful evaluation of morphological features such as mitotic figures and cellular atypia is crucial in the diagnostic work-up of triple-negative breast lesions. It is important to keep cylindroma in mind as a pitfall and possible differential diagnosis for the solid-basaloid variant of adenoid cystic carcinoma. Molecular detection of CYLD gene mutation is helpful in cases with ambiguous histology. With this case report, we aim to contribute to a better understanding of mammary cylindroma and facilitate the diagnosis of this rare entity.

Optimal surgical procedure for treating early-stage adenoid cystic carcinoma of the breast

To explore the superiority of breast conservation surgery (BCS) to mastectomy in treating early-stage adenoid cystic carcinoma of the breast (BACC). Patients with surgically treated stage I/II BACC were enrolled between 2000 and 2019 in the SEER database; they were divided into the BCS and mastectomy groups. Overall survival (OS) and disease-specific survival (DSS) were compared between the two groups, and Cox hazard regression models were used to determine the independent predictors. Of the 583 patients in the study, 386 were included in the BCS group. The 10-year OS rates for the BCS and mastectomy groups were 78% (95% CI: 74-82%) and 76% (95% CI: 70-82%), respectively, but the difference was not statistically significant (p = 0.968). The 10-year DSS rates for the BCS and mastectomy groups were 95% (95% CI: 93-97%) and 89% (95% CI: 85-93%), respectively, and the difference was statistically significant (p = 0.002). Pathological examination of regional lymph nodes and adjuvant treatment were not associated with improved OS or DSS, but age, disease grade, and lymph node metastasis were independent prognostic factors. For stage I/II BACC, BCS can achieve more satisfactory 10-year OS and DSS than mastectomy.

[Surgery of primary tracheal tumors]

OBJECTIVE

To determine the main forms of primary tracheal cancer (PTC), to specify the indications for various surgeries in these patients depending on extent and localization of lesion.

MATERIAL AND METHODS

There were 263 PTC patients. Benign tumors were diagnosed in 68 (25.9%) patients, malignancies - in 195 (74.1%) cases. Tracheal cancer includes 3 basic morphological variants - adenocystic cancer (49.7%), carcinoid (18.7%) and squamous cell carcinoma (19.0%). Other forms of malignancies were much less common. We applied endoscopic intraluminal and open surgeries. In malignant PTC, open surgeries were performed in 165 (84.6%) out of 195 patients. Baseline palliative endoscopic treatment was performed in 30 patients. They underwent airway recanalization (with subsequent tracheal stenting in 19 patients). Endoscopic resection was preferred for benign tumors.

RESULTS

Twenty (12.1%) patients died after open surgery, and 1 (3.3%) patient died after endoscopic procedure. Most lethal outcomes occurred in early years of development of tracheal surgery. The causes of mortality were tracheal anastomotic failure in 12 patients, pneumonia in 6 patients, and arterial bleeding in 2 patients. Severe postoperative period was observed in all 3 patients after tracheal replacement with a silicone prosthesis. Long-term treatment outcomes depended on morphological structure of PTC. Favorable results were observed in patients with neuroendocrine tumor (carcinoid), worse outcomes in adenocystic cancer and unfavorable results in squamous cell carcinoma (p<0.0013). Five-year survival rates were 75%, 65.6%, and 13.3%; 10-year survival rates were 75%, 56.2%, and 13.3%, respectively. These outcomes after combined treatment of primary tracheal cancer were significantly better compared to lung cancer (p<0.05 when compared to global data).

CONCLUSION

Treatment of primary tracheal cancer should be based on classical principles of modern oncology (combined therapy, tumor resection with lymphadenectomy). Open and endoscopic interventions are justified. PTC is characterized by more favorable outcomes compared to lung cancer. It is difficult to analyze long-term results in tracheal cancer depending on various features of tumor process due to small number of observations. Accurate conclusions require multiple-center studies, preferably with international participation, which can convincingly prove certain concept.