Tall cell carcinoma of the breast with reversed polarity (TCCRP) with mutations in the IDH2 and PIK3CA genes: a case report

Tall Cell Carcinoma with Reversed Polarity of the breast: Clinicopathological insights, molecular profile, and future therapeutic directions

Tall Cell Carcinoma with Reversed Polarity (TCCRP) is a rare and distinct subtype of invasive breast carcinoma, first described in 2003. It is histologically characterized by tall columnar epithelial cells with reversed nuclear polarity and shares morphological features with papillary thyroid carcinoma (PTC). However, its unique molecular signature, including IDH2 and PIK3CA mutations, differentiates it from other breast cancer subtypes. A retrospective systematic study of 91 published cases of TCCRP was conducted, including two cases from our institution. Clinical, pathological, molecular, and treatment-related data were collected and analyzed. Descriptive statistics and Kaplan-Meier survival analysis were employed to evaluate disease-free survival (DFS) and overall survival (OS). Subgroup analyses explored associations between clinical features, molecular markers, and outcomes. The median age at diagnosis was 64 years, with a predominance of small tumors (mean size: 10.4 mm, T1 stage). Histologically, hallmark features included reversed nuclear polarity (100 %), nuclear grooves, and intranuclear pseudoinclusions. Immunohistochemical analysis confirmed a triple-negative profile (ER-/PR-/HER2-) in most cases, with consistent breast-specific marker expression (GATA3, CK7). Molecular testing revealed frequent IDH2 R172 (84.6 %) and PIK3CA (72.5 %) mutations. Surgical management, predominantly breast-conserving surgery (BCS), was the primary treatment, with adjuvant therapies rarely utilized. At a median follow-up of 35.8 months, recurrence occurred in only 2.2 % of cases, and the overall survival rate was 100 %. TCCRP is a rare, low-grade breast cancer subtype with a favorable prognosis and low recurrence risk based on currently available data, but longer follow-up studies are needed to confirm this observation. Its distinct histological and molecular features enable accurate diagnosis and differentiation from other breast cancers and metastatic thyroid carcinoma. Given its indolent nature, conservative treatment strategies, including BCS, are effective, and adjuvant therapies can be minimized. Future research should explore targeted therapies for IDH2 and PIK3CA mutations to expand treatment options for this unique subtype.

Tall cell carcinoma with reverse polarity of the breast in a young patient: A case report

INTRODUCTION AND IMPORTANCE

Tall cell carcinoma with reverse polarity (TCCRP) is a rare and newly recognized subtype of invasive breast carcinoma, first described in 2003. It shares histological similarities with tall cell papillary thyroid carcinoma, characterized by papillary structures with reverse cellular polarity. Due to its rarity, TCCRP has been poorly understood, and fewer than 100 cases have been reported globally. This report presents the first case of TCCRP in South Tunisia, contributing to the growing body of knowledge regarding this rare tumor.

CASE PRESENTATION

A 34-year-old woman with no significant personal or family history of breast cancer presented with an incidental finding of a 1 cm breast mass. Imaging studies revealed an atypical mass classified as ACR 4a. Histological analysis following lumpectomy showed circumscribed nests of epithelial cells with delicate fibrovascular cores, resembling papillary structures. Immunohistochemical staining revealed diffuse positivity for cytokeratin 5/6 and calretinin, and negativity for estrogen, progesterone, HER-2, and TTF1. The diagnosis of TCCRP was confirmed. The tumor was classified as SBR grade I, with no lymphovascular invasion or carcinoma in situ. No metastasis was observed in the 31 axillary lymph nodes.

CLINICAL DISCUSSION

TCCRP primarily affects women over 60, with a low incidence in younger individuals. It typically presents as a small, palpable breast mass. Histologically, TCCRP exhibits a solid-papillary architecture with tall cells, reverse polarity, and rare foamy histiocytes. Immunohistochemical findings include negative estrogen, progesterone, HER-2, and TTF1 markers, along with positive staining for calretinin. Molecular studies have revealed IDH2 and PIK3CA mutations in the majority of cases. Despite being triple-negative, TCCRP has a favorable prognosis, with low rates of metastasis or recurrence.

CONCLUSION

TCCRP is a rare subtype of invasive breast carcinoma with distinct histological and immunohistochemical features. It is characterized by an indolent clinical course and an excellent prognosis. Conservative surgical management with clear margins is the optimal treatment approach, with no clear indications for lymph node dissection, chemotherapy, or radiotherapy.

A new subtype of papillary ductal carcinoma in situ with tall cell and reversed polarity morphology: a rare case report

BACKGROUND

According to previous studies, tall cell carcinoma with reversed polarity can be easily distinguished from ductal carcinoma in situ based on the absence of myoepithelium and a typical histologic feature. However, to the best of our knowledge, no cases of papillary ductal carcinoma exhibiting tall cell and reversed polarity features with intact myoepithelium have been reported, and thus its diagnosis and prognosis remain unclear.

CASE PRESENTATION

A 54-year-old female with a palpable lump in her right breast for 3 years. There were no other symptoms found. A preoperative ultrasound examination showed an oval, well-circumscribed, anechoic cystic appearance with hypoechoic adnexal nodules, classified as 3-4a in the Breast Imaging Reporting Data System. Surgical excision revealed an in-situ breast carcinoma exhibiting a solid papillary pattern and tall cell with reversed polarity of nuclei. After thorough postoperative pathology, immunohistochemistry, and next-generation sequencing, we hypothesized that it might be a new ductal carcinoma in situ subtype with tall cells and reversed polarity of the mammary gland.

CONCLUSIONS

We herein present a rare case of papillary ductal carcinoma in situ with tall cell and reversed polarity morphology breast cancer, which can closely mimic tall cell carcinoma with reversed polarity and ductal carcinoma in situ. Thorough evaluations of histologic features, immunohistochemistry results, and genetic alterations are significant in identifying this rare entity. In addition, this type of breast cancer is low-malignant and has a favorable prognosis without any adjuvant therapy after complete resection.

Clinicopathological characterization of tall cell carcinoma with reversed polarity of the breast: A case report and review of the litterature

INTRODUCTION

Tall cell carcinoma of the breast with reverse polarity (TCCRP) is a recently described rare entity with low potential for malignancy which exhibits morphological features with tall cell variant of papillary thyroid carcinoma. Immunohistochemical and molecular studies help establish the diagnosis.

CASE REPORT

We report the case of a 45-year-old woman with no significant medical or surgical history who presented with mastodynia. Physical examination was negative. Screening by bilateral mammography revealed a mass of the right breast which was classified as 4B. The mass was surgically excised. The pathological report concluded to a TCCRP of the breast with free margins. The tumor cells were negative for hormone receptors as well as for the Human Epidermal Growth Factor Receptor-2 (HER2neu). The patient underwent a sentinel lymph node dissection that was negative followed by loco-regional radiotherapy. Chemotherapy and endocrine therapy were not indicated for the patient. After 24 months of follow-up, no signs of loco-regional or distant recurrences have been identified.

CLINICAL DISCUSSION

TCCRP is a rare entity that has been recently introduced in the WHO classification of breast cancer. It is usually a triple negative tumor, negative to TTF1 and thyroglobulin with low proliferation index, and a low potential for malignancy. Wide excision is the keystone of the treatment; however, chemotherapy and radiotherapy are still controversial due to lack of evidence.

CONCLUSION

TCCRP is a rare entity, which carries an excellent prognosis. A proper diagnosis is essential to conduct the best treatment next to a careful follow-up due to the ambiguous natural history of this rare entity.

PAPERS THAT HAVE BEEN PREVIOUSLY PUBLISHED AS MEETING ABSTRACTS

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Case report: Tall cell carcinoma with reversed polarity of the breast: an additional case and review of the literature

Objective

The aim of this report was to comprehensively investigate the clinicopathological features, histological characteristics, and differential diagnosis of tall cell carcinoma with reversed polarity of the breast (TCCRP) to enhance the understanding of this tumour for precise therapeutic interventions.

Methods

The clinicopathological characteristics and differential diagnosis of a patient with TCCRP were retrospectively analysed, and a systematic literature review was extracted from relevant published studies on PubMed.

Results

All patients included in the study were female, with a median age of 51 years. Microscopically, the tumour cells exhibited a solid papillary growth pattern with tall columnar morphology and reversed nuclear polarity. Immunohistochemistry revealed that the tumours were triple-negative breast cancer (negative for ER, PR, and HER-2), with a low Ki-67 proliferation index. Different degrees of expression were observed for CK7, Calretinin, and S-100 markers; however, CK5/6 showed high expression levels.

Conclusions

TCCRP is an uncommon invasive carcinoma subtype found in the breast. Its histological morphology resembles that of tall cell subtype papillary thyroid carcinoma. Accurate diagnosis requires the integration of histomorphological assessment along with immunohistochemistry and molecular genetics analysis.

Molecular pathology in breast disease: diagnostic, prognostic, and therapeutic tools

Molecular testing in breast cancer gained increasing attention and importance as specific molecular results can tailor not only oncological decisions on systemic adjuvant or neoadjuvant or in metastatic setting, but increasingly serve in diagnostic routine histopathological services to differentiate between morphologically overlapping or ambiguous histological pictures. Diagnostic tools involve in most cases a broad spectrum of immunohistochemical panels, followed by entity-specific in situ hybridization probes and in given cases NGS-based sequencing. Workflow of which methodology is applied and in which order depends on the specific entity resp. on the given differential diagnosis in question. Regarding prognostic/predictive molecular testing, the choice of assay and the workflow are based on clinical algorithms and on the evidence of targeted therapies following the molecular alterations. In this review paper, we aim to address the use of molecular technics in [1] the histological diagnostic setting (such as subtyping of invasive carcinomas/malignant spindle cell tumors and sarcomas and some B3 lesions) and [2] in the context of adjuvant or neoadjuvant or other clinical settings with special focus of targeted therapies.

Tall Cell Carcinoma with Reversed Polarity: Case Report of a Rare Special Type of Breast Cancer and Review of the Literature

Background: Tall cell carcinoma of the breast with reversed polarity (TCCRP) is a rare type of invasive breast cancer with overlapping features with papillary thyroid carcinoma and a characteristic molecular profile. Few cases have been reported in the literature since the first case was described in 2003. Case presentation: We present the case of a 41-year-old female with a symptomatic left breast lump. Image-guided core biopsy was diagnosed as triple-negative apocrine carcinoma. Surgical excision revealed an invasive carcinoma with solid papillary pattern, nuclei arranged away from the basement membrane (reversed polarity) and luminal eosinophilic colloid-like material. The tumour was GATA3-, CK5-, CK14- and CK7-positive and TTF1-negative. Specialist opinion and the identification of hotspot mutations in the IDH2 p.Arg172 gene via PCR confirmed the diagnosis of TCCRP. Conclusions: TCCRP is a relatively recently recognised papillary epithelial neoplasm with characteristic morphological features and molecular profile. Due to its rarity, TCCRP can be diagnostically challenging, and features can be mistaken for benign and malignant lesions. Accurate diagnosis is important in effective treatment of this indolent malignant triple-negative breast cancer, which carries an excellent prognosis.

The Diagnostic Utility of IDH2 R172 Immunohistochemistry in Tall Cell Carcinoma With Reversed Polarity of the Breast

Tall cell carcinoma with reversed polarity (TCCRP) is a rare histologic type of low-grade breast cancer, consisting of tall columnar cells with reversed nuclear polarity and characterized by frequent IDH2 mutations. We herein report 3 cases of TCCRP with sequencing analyses of the IDH2 gene and immunohistochemical examination using monoclonal antibodies (11C8B1) against IDH2 R172. IDH2 R172 mutations were detected in all 3 resected tumors (R172S in 2 tumors and R172T in 1 tumor), and the presence of these mutations was confirmed by IDH2 R172 immunohistochemistry. Tumor cells of TCCRP showed strong and diffuse staining for the antibody against IDH2 R172. In 1 case, tumor tissue from 2 core needle biopsy samples collected on different days were also immunohistochemically positive for IDH2 R172. These results indicate that IDH2 R172 immunohistochemistry is suitable for the detection of TCCRP in both resection and biopsy samples. In addition, a literature review revealed that R172S and R172T account for 76% of IDH2 mutations in TCCRP, suggesting that 11C8B1, which reacts with R172S and R172T, was likely most sensitive for IDH2-mutated TCCRP among many available antibodies for IDH2 R172. Furthermore, the combination of 2 or more antibodies against IDH2 R172 could be more effective for detecting TCCRP mutation. However, it is important to note that IDH2 R172 immunohistochemistry is not absolute, because IDH2 wild type is found in a small proportion (10%) of cases, and a few cases of IDH2-mutated TCCRP may harbor rare subtypes of R172 that are not covered by available antibodies.

Papillary lesions of the breast - review and practical issues

Papillary lesions of the breast represent a heterogeneous group of neoplasm featuring fibrovascular cores covered by epithelial cells with or without intervening myoepithelial cells. According to the World Health Organization classification of breast tumors, papillary lesions of the breast are further classified into intraductal papilloma (including intraductal papilloma with atypical ductal hyperplasia /ductal carcinoma in situ), papillary ductal carcinoma in situ, encapsulated papillary carcinoma, solid papillary carcinoma (in situ and invasive) and invasive papillary carcinoma. The overlapping morphological features and immunohistochemical profiles make accurate diagnosis of breast papillary lesion a challenge for pathologists. In this review, the morphological and relevant immunohistochemical features of papillary lesions are discussed, with further emphasis on some commonly encountered practical diagnostic issues. A simple diagnostic algorithm will be established. The relevant molecular characteristics will be discussed as well.

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.

Low-risk triple-negative breast cancers: Clinico-pathological and molecular features

Triple-negative breast cancers (TNBC) comprise biologically and clinically heterogeneous diseases characterized by the lack of hormone receptors (HR) and HER2 expression. This subset of tumors accounts for 15-20% of all breast cancers and pursues an ominous clinical course. However, there is a spectrum of low-risk TNBCs with no/minimal metastatic potential, including the salivary gland-type tumors, those with extensive apocrine differentiation and/or high tumor-infiltrating lymphocytes, and small-sized, early-stage (pT1a/bN0M0) TNBCs. De-escalating the treatment in low-risk TNBC, however, is not trivial because of the substantial lack of dedicated randomized clinical trials and cancer registries. The development of new diagnostic and/or prognostic biomarkers based on clinical and molecular aspects of low-risk TNBCs would lead to improved clinical treatment. Here, we sought to provide a portrait of the clinicopathological and molecular features of low-risk TNBC, with a focus on the diagnostic challenges along with the most important biological characteristics underpinning their favorable clinical course.

Tall cell carcinoma with reversed polarity: case report with gene sequencing and literature review

Tall cell carcinoma with reversed polarity (TCCRP) is an extremely rare type of invasive breast cancer with only 17 literatures and 75 cases reported. Knowledge on TCCRP is still scanty. The present study reported 2 cases of TCCRP, analyzed their clinicopathological characteristics, and used whole exome sequencing to perform genetic testing. Both two cases were proved to have typical clinicopathological manifestations (solid and papillary architectures lined by tall columnar cells with nuclei displaying "reverse polarization") and hotspot mutations (IDH2 and PIK3CA mutations) of TCCRP. Furthermore, positive expression of TTF-1 was found in a small number of tumor cells nuclei and normal ductal epithelial cells, while the negative rate of TTF-1 in previous case reports was 100%. Attention should be paid in core needle biopsy to avoid misdiagnosis. In addition, this article also reviewed all previous cases and demonstrated that the positive expression of calretinin might have an indicative significance for TCCRP, which could be used as one of the auxiliary diagnosis tools. The diagnosis of TCCRP requires comprehensive analysis of clinical pathology and genetic testing results. There is no clear treatment standard for TCCRP currently, further research should be reported to characterize and deeply investigate the diagnosis and treatment criteria of TCCRP.

Tall Cell Carcinoma With Reversed Polarity of the Breast

Tall cell carcinoma with reversed polarity (TCCRP) of the breast is a rare entity with low potential for malignancy that exhibits some morphological similarities to the tall cell variant of papillary thyroid carcinoma. Immunohistochemical and molecular studies help establish the mammary origin of this neoplasm. Here, we describe the case of a 63-year-old woman with a finding of a nodular lesion during a screening mammogram, whose morphological findings and immunohistochemical studies confirmed the diagnosis of papillary high cell carcinoma with the reverse polarity of the mammary gland.

Triple-negative breast carcinomas of low malignant potential: review on diagnostic criteria and differential diagnoses

Triple-negative breast carcinomas constitute a wide spectrum of lesions, mostly being highly aggressive. Nevertheless, some special histologic subtypes can have low malignant potential. The purpose of the present paper is to review diagnostic criteria and prognostic parameters of breast neoplasms of special histotypes. Specifically, adenoid cystic carcinoma, adenomyoepithelioma, acinic cell carcinoma, mucoepidermoid carcinoma, tall cell carcinoma with reverse polarity, and secretory carcinoma will be discussed. For each tumour, definition and morphological and molecular features, together with prognostic parameters, will be presented. Paradigmatic cases will be illustrated.

Breast carcinomas of low malignant potential

Some breast carcinomas have a very low likelihood of metastasis to regional lymph nodes and distant sites and may be considered carcinomas of low malignant potential. In this article, we review the clinical, pathologic, immunophenotypic, and molecular features of selected breast carcinomas of low malignant potential including low-grade adenosquamous carcinoma, fibromatosis-like metaplastic carcinoma, encapsulated papillary carcinoma, solid papillary carcinoma, and tall cell carcinoma with reversed polarity.

Tall cell carcinoma of the breast with reverse polarity: case report with gene sequencing and literature review

Tall cell carcinoma of the breast with reverse polarity (TCCRP), described firstly and also known as tall cell variant of papillary breast carcinoma (TCVPBC), is a rare type of breast cancer that mimics papillary thyroid carcinoma (PTC) histopathologically. As the incidence of this type of tumor is very low, awareness of it is crucial to ensuring that unnecessary clinical investigations are avoided. The present study examined a 45-year-old woman in China who was diagnosed with TCCRP. This paper outlines her demographic and clinicopathologic data, and her follow-up and immunohistochemical examination results. Furthermore, this study used the next-generation sequencing (NGS) technique to identify concurrent isocitrate dehydrogenase 2 (IDH2) and phosphatidylinositol 3-kinase catalytic alpha (PIK3CA) hotspot mutations. Notably, the novel results of the study showed that the IDH2 R120 (rather than the IDH2 R172) mutation may also be present in this disease. Additionally, a comprehensive literature review was conducted to elucidate some of the significant clinical and pathological features of this type of disease. This information may provide important insights that can be used in diagnosis and treatment. It is essential both for physicians and pathologists to recognize the existence of TCCRP, with its own specific clinical and pathological characteristics. Further research using molecular biology techniques should be conducted in the future to characterize this unique entity.