obsolete pleomorphic adenoma of the breast

Pleomorphic Adenoma of the Breast: A Rare and Misdiagnosed Tumor

Pleomorphic adenoma of the breast is a rare, benign tumor that accounts for less than 100 reported cases in the literature. It primarily occurs in post-menopausal women, frequently in a peri-areolar location [10]. This tumor is characterized by an admixture of epithelial and myoepithelial cells embedded in abundant myxomatous stroma [12].

Clinical and Histologic Appearance

The clinical appearance of pleomorphic adenoma can be challenging and may lead to misdiagnosis of invasive carcinoma. The tumor is typically well-circumscribed, with a greatest dimension of up to 5.5 cm [11]. Pathologists should keep this tumor in mind when encountering a tumor with a prominent myxomatous stroma.

Diagnosis and Treatment

Careful diagnosis based on paraffin sections is necessary to prevent unnecessary surgical overresection. Local excision with clear margins is an appropriate treatment for pleomorphic adenoma of the breast [14]. In cases of inconclusive and equivocal FNAC reports, intraoperative frozen section examination can help in the diagnosis and provide valuable information regarding the margins of resected tumor [15].

Key Points

• Pleomorphic adenoma of the breast is a rare, benign tumor accounting for less than 100 reported cases.
• It primarily occurs in post-menopausal women, frequently in a peri-areolar location.
• The clinical appearance can be challenging and may lead to misdiagnosis of invasive carcinoma.
• Local excision with clear margins is an appropriate treatment.
• Careful diagnosis based on paraffin sections is necessary to prevent unnecessary surgical overresection.

References:

[10] Chen, 1990; Foschini et al., 2017; Sato et al., 2005 [12] Abstract. Pleomorphic adenoma of the breast is a rare, benign tumor accounting for 68 cases in the literature. [14] Mastology 221;31:e2200064 1 Pleomorphic adenoma of the breast Marina Sonagli1* , Georgia Terra Lustre di Flora1, Tábata Alves Domingos1, Vinicius Felipe Cardona1 1, Solange Maria Torchia de Carvalho , Cynthia Aparecida Bueno de Toledo Osório1, Fabiana Baroni Alves Makdissi1 [15] An excision of PA adenoma should be ideally performed with the help of frozen section analysis.

Diagnostic Tests for Obsolete Pleomorphic Adenoma of the Breast

Pleomorphic adenoma, also known as a benign mixed tumor, is a rare type of tumor that can occur in the breast. While it's not commonly found in the mammary gland, its diagnosis and management are crucial to prevent misinterpretation with malignant tumors.

Diagnostic Modalities:

• Ultrasound: A 5.5 cm hypoechoic mass with lobulated margins was noted on ultrasound in a reported case of pleomorphic adenoma of the breast [12].
• Biopsy: A biopsy showed an atypical cartilaginous lesion, leading to a diagnosis of pleomorphic adenoma [12]. Fine-needle aspiration and core needle biopsy are useful tools for diagnosing fibroadenomas but may not be sufficient for phyllodes tumors, which require excisional biopsy [5].
• Frozen Section Analysis: An intraoperative frozen section examination can help in the diagnosis of pleomorphic adenoma with classical histomorphology and provide valuable information regarding the margins of resected tumor [15].

Other Diagnostic Considerations:

• Pleomorphic adenoma might be misinterpreted clinically and pathologically as a malignant tumor, so differential diagnoses include fibroadenoma, phyllodes tumor, and metaplastic carcinoma [13].
• Molecular testing in breast cancer can provide diagnostic, prognostic, and therapeutic information, but its application may vary depending on the specific tumor subtype [14].

References:

[1] Cserni G. (2022). Core needle biopsy sampling in surgical procedures. [Cited by 15]

[5] Fine-needle aspiration and core needle biopsy for diagnosing fibroadenomas.

[12] Pleomorphic adenoma of the breast: a rare case report.

[13] Differential diagnoses for pleomorphic adenoma.

[14] Molecular testing in breast cancer.

[15] Intraoperative frozen section examination for pleomorphic adenoma.

Treatment Options for Obsolete Pleomorphic Adenoma of the Breast

Pleomorphic adenoma of the breast, also known as a salivary-type tumor, is a rare and benign neoplasm that primarily occurs in post-menopausal women. While surgical excision with adequate margins is the treatment of choice, there are limited options for drug treatment.

• Trastuzumab: A patient with HER2-positive pleomorphic adenoma achieved a complete response for over two years with trastuzumab in combination with capecitabine [1]. However, this case report highlights the rarity and variable histologic appearance of breast pleomorphic adenomas, making it challenging to recognize and treat.
• Chemotherapy: When chemotherapy is considered in HER2-negative patients, the combination of carboplatin with a taxane should be considered [2]. However, there is limited evidence on the effectiveness of chemotherapy for pleomorphic adenoma of the breast.
• Targeted therapies: HER2-directed therapies, including trastuzumab, pertuzumab, tucatinib, TDM1, and TDxd, have been effectively used in multiple cancer types that over-express HER2 [7]. However, their efficacy in treating pleomorphic adenoma of the breast is unknown.

Current Recommendations

The recommended treatment for pleomorphic adenoma of the breast is local resection with 3 mm of clear margins to avoid disruption of the tumor capsule [14]. This approach aims to minimize recurrence and ensure adequate excision. In cases where surgery is not feasible, definitive radio(chemo)therapy may be considered [9].

Future Directions

Further research is needed to explore effective drug treatment options for pleomorphic adenoma of the breast. Given the rarity and variable histologic appearance of this tumor, collaborative efforts between clinicians and researchers are essential to develop evidence-based guidelines for diagnosis and treatment

Based on the provided context, it appears that pleomorphic adenoma of the breast (PAB) can be challenging to diagnose and may be misinterpreted as other conditions.

Possible Differential Diagnoses:

• Metaplastic carcinoma [10]
• Fibroadenoma [13]
• Phyllodes tumor [13]
• Malignant adenomyoepithelioma [2]

These differential diagnoses are mentioned in the context, which suggests that PAB can be confused with other