Invasive solid papillary carcinoma with neuroendocrine differentiation of the breast: a case report and literature review

Morphologically In Situ Solid Papillary Carcinoma of the Breast With Lymph Node and Lung Metastasis: A Rare Case Report and Literature Review

Solid papillary carcinoma (SPC) is rare, accounting for less than 1% of all breast cancers. According to the 5th edition of the WHO Classification of Breast Tumors (2019), SPC is divided into invasive (ISPC) and in situ (SPC in situ) subtypes. ISPC is characterized by an irregular or jigsaw pattern lacking myoepithelial cells, while SPC in situ is well-circumscribed, regardless of myoepithelial cell presence. Metastasis is infrequently reported, with most patients involving lymph nodes and arising from ISPC. Metastases from SPC in situ without myoepithelial cells have rarely been reported. We present a 66-year-old woman with a 28 × 13 mm hypoechoic breast mass detected on ultrasound. Microscopic examination revealed well-circumscribed nests of SPC, positive for ER, PR, and synaptophysin, with a Ki-67 proliferation index of 10%. HER2 was negative. Myoepithelial markers, including p63, smooth muscle actin, keratin 5/6, p40, and CD10, were all negative, confirming the absence of a myoepithelial layer. Axillary lymph node dissection revealed metastasis in three of eighteen lymph nodes, with the metastatic foci demonstrating the same well-circumscribed SPC architecture as the primary tumor in the breast. Additionally, a lung biopsy exhibited metastatic SPC with identical histomorphology and immunohistochemical profile to the primary tumor. Although rare, SPC presenting a well-circumscribed morphology, and classified as in situ according to the WHO, should be approached with caution when myoepithelial cells are absent, as the in situ histomorphology does not necessarily exclude the potential for metastasis.

Solid Papillary Carcinoma with Invasion in the Male Breast: A Case Report and Literature Review

Introduction

Solid papillary carcinoma (SPC) accounts for approximately 1% of all breast cancer cases and occurs primarily in postmenopausal women. We report a rare SPC with invasion in the male breast.

Case Presentation

A 73-year-old Japanese man presented with bloody nipple discharge and a palpable left breast mass. Mammography revealed a well-defined high-concentration mass. Ultrasonography scans demonstrated an intracystic 10 mm mass under the left nipple without enlarged axillary lymph nodes. A core needle biopsy revealed a ductal carcinoma with nuclear grade 1, which excluded an invasive carcinoma. Magnetic resonance imaging exhibited a 7 mm intense early enhancement in the left breast. A left mastectomy and sentinel lymph node biopsy were performed. The patient was diagnosed with pathological stage IA (T1b N0 M0) breast carcinoma, an invasive pure SPC type without neuroendocrine markers. The patient was treated with oral tamoxifen and survived without any recurrence for 12 months.

Conclusion

Invasive SPC of the male breast may occur as a palpable mass or nipple discharge in older men and has a good prognosis.

Infiltrative solid papillary carcinoma of the breast with axillary lymph node metastasis: a case report

BACKGROUND

Solid papillary carcinoma (SPC) is a rare breast papillary tumor variant. The main histological features of SPC consist of neoplastic cell-rich nodules with thin fibrovascular cores, often accompanied by mucous secretion and neuroendocrine differentiation. Infiltrative solid papillary carcinoma (ISPC) tumor cells have an invasive, map-like growth pattern with serrated irregular growth. Due to its unique clinicopathological features, SPC is classified as two pathological tissue types based on the 2019 WHO classification of breast tumors: SPC in situ and ISPC.

CASE PRESENTATION

We report a case of a 55-year-old female patient who was admitted to the hospital due to a painless left breast mass that had persisted for two years. Mammography suggested a mass in the left upper outer quadrant (BI-RADS 4B), and ultrasound of the breast demonstrated a cystic mass of the left breast (US_BI_RADS 4 C) with multiple enlarged lymph nodes in the left axilla. Postoperative pathology revealed ISPC with one lymph node metastasis in the left breast. Modified radical mastectomy was performed on the left breast. Subsequently, the patient received letrozole endocrine therapy, epirubicin hydrochloride and cyclophosphamide chemotherapy, and radiotherapy of the left chest wall and left upper and lower clavicular regions. After 17 months of follow-up, there was no evidence of recurrence or distant metastasis.

CONCLUSIONS

SPC is a group of heterogeneous tumors. SPC in situ has a good prognosis. In contrast, ISPC has a unique histological morphology and growth pattern with invasive biological behavior that can lead to lymph node and distant metastases.

Cytological study of 44 cases with solid papillary carcinoma and a systemic review of solid papillary carcinoma and neuroendocrine tumor of the breast

BACKGROUND

Solid-papillary carcinoma (SPC) of the breast is a rare variant of low-grade in situ and invasive carcinoma but there are only a few of the cytologic studies.

METHODS

We examined 44 cases of SPC of the breast to define the cytologic features. We also made a systemic review of reported cases of SPC and neuroendocrine tumor (NET) of the breast.

RESULTS

Both of our and the reviewed cases with SPC were very similar in the cytologic finding. It included hypercellularity, highly discohesive clusters, numerous isolated cells, small nuclei, finely granular chromatin of salt-and-pepper appearance, inconspicuous nucleoli, low nuclear-cytoplasmic ratio, and a plasmacytoid appearance. Moreover, SPC and NET had frequently all of these features in common. Capillary vessels structures and mucinous substance were not frequently seen in our and the reviewed cases with SPC. Rosette and pseudorosette were very rare in the cytologic specimen. The immunocytochemistry with our 9 cases with SPC indicated diffuse positivity for chromogranin A and/or synaptophysin.

CONCLUSION

Many cytologic features are frequently shared by SPC and NET of the breast. However, the vascular structure may not be a precise criterion for SPC. Rosette and pseudorosette are rarely helpful for the cytologic diagnosis.

Invasive Micropapillary Carcinoma of the Breast With Solid Papillary Carcinoma: A Case Report

Invasive micropapillary carcinoma and Solid papillary carcinomas are rare histologic subtypes of breast cancer. Co-existence of tumors of the breast like invasive ductal and lobular carcinomas, or invasive ductal carcinoma and mucinous carcinomas have been reported before. But the existence of invasive micropapillary carcinoma with solid papillary carcinoma is a rare occurrence. Here, we are reporting a rare case of a 60-year-old female with a mass in her left breast. The histopathology report showed a tumor containing these two histologic subtypes. Recognition of all tumor subtypes is necessary, as this can impact the treatment strategy.

Clinicopathological Characteristics and Prognostic Profiles of Breast Carcinoma with Neuroendocrine Features

BACKGROUND

Breast carcinoma with neuroendocrine features includes neuroendocrine neoplasm of the breast and invasive breast cancer with neuroendocrine differentiation. This study aimed to investigate the clinicopathological features and prognosis of this disease according to the fifth edition of the World Health Organization classification of breast tumors.

MATERIALS AND METHODS

A total of 87 patients with breast carcinoma with neuroendocrine features treated in the First Medical Center, Chinese PLA General Hospital from January 2001 to January 2022 were retrospectively enrolled in this study.

RESULTS

More than half of the patients were postmenopausal patients, especially those with neuroendocrine neoplasm (62.96%). There were more patients with human epidermal growth factor receptor 2 negative and hormone receptor positive tumors, and most of them were Luminal B type (71.26%). The multivariate analysis showed that diabetes and stage IV disease were related to the progression-free survival of breast carcinoma with neuroendocrine features patients (p = 0.004 and p < 0.001, respectively).

CONCLUSION

Breast carcinoma with neuroendocrine features tended to be human epidermal growth factor receptor 2 negative and hormone receptor positive tumors, most of them were Luminal B type, and the related factors of progression-free survival were diabetes and stage IV disease.

The Spectrum of Mucinous Lesions of the Breast

CONTEXT.—

Mucinous lesions of the breast encompass many entities ranging from benign to malignant and nonneoplastic to neoplastic. Lesions discussed under this category are mucocele-like lesion, mucinous carcinoma, mucinous micropapillary carcinoma, solid papillary carcinoma, mucinous cystadenocarcinoma, mucoepidermoid carcinoma, invasive lobular carcinoma with extracellular mucin, mucinous ductal carcinoma in situ, and metastasis.

OBJECTIVE.—

To review clinical, pathologic, and molecular features of mucinous lesions of the breast, their differential diagnoses, and challenging features on core needle biopsies.

DATA SOURCES.—

The existing scientific and clinical literature as of December 2021.

CONCLUSIONS.—

The category of mucinous lesions of the breast is vast and the differential diagnosis can be challenging, especially on core needle biopsies. In all cases, clinical, radiologic, and pathologic correlation is necessary to reach a comprehensive diagnosis. Given that the prognosis and management of each entity is different, being aware of these entities and their nuances is critical for a pathologist to guide accurate management.