Spindle Cell Lesions of the Breast: A Diagnostic Algorithm

Malignant phyllodes tumor of the breast with predominant osteosarcoma and chondrosarcomatous differentiation: a rare case report and review of literature

Background

Phyllodes tumors (PTs), which account for less than 1% of mammary gland tumors, composed of both epithelial and stromal components. If a malignant heterologous component is encountered, PT is considered malignant. Malignant phyllodes tumors (MPTs) only account for 8% to 20% of PTs. We report a case of MPT with osteosarcoma and chondrosarcoma differentiation and review the literature to discuss the differential diagnosis and therapy.

Case presentation

A 59-year-old Chinese woman come to our hospital because of a palpable mass she had had for 1 months in the left breast. Preoperative core needle biopsy (CNB) was performed on the left breast mass on January 11, 2023. Pathological diagnosis was malignant tumor, the specific type was not clear. Mastectomy and sentinel lymph node biopsy of the left breast was performed. No metastasis was found in 3 sentinel lymph nodes identified by carbon nanoparticles and methylene blue double staining. Heterologous osteosarcoma and chondrosarcomatous differentiation of phyllodes tumor were observed. Immunohistochemistry: spindle tumor cells ER(-), PR(-), HER-2(-), CK-pan(-), CK7(-), CK8(-), SOX10(-), S100(-), and MDM2(-), CK5/6(-), P63(-), P40(-) were all negative. CD34:(+), SATB2(+), P53(90% strong), CD68 (+), Ki-67(LI: about 60%). No ductal carcinoma in situ was found in the breast. Fluorescence in situ hybridization (FISH) indicated USP6 was negatively expressed on formalin-fixed, paraffin-embedded (FFPE) tissue sections.

Conclusion

MPTs are rare, and heterologous differentiation in MPTs is exceedingly rare. It could be diagnosed by pathology when metaplastic carcinoma, primary osteosarcoma, or myositis ossificans were excluded. This case could help clinicians to improve the prognosis and treatment of this disease.

Diagnostic Pitfalls in Breast Cancer Pathology With an Emphasis on Core Needle Biopsy Specimens

CONTEXT.—

Breast pathology has many mimics and diagnostic pitfalls. Evaluation of malignant breast lesions, particularly in the biopsy setting, can be especially challenging, with diagnostic errors having significant management implications.

OBJECTIVE.—

To discuss the pitfalls encountered when evaluating ductal carcinoma in situ and invasive breast carcinomas, providing histologic clues and guidance for appropriate use and interpretation of immunohistochemistry to aid in the correct diagnosis.

DATA SOURCES.—

Data were obtained from review of pertinent literature of ductal carcinoma in situ and invasive breast carcinomas and from the experience of the authors as practicing breast pathologists.

CONCLUSIONS.—

Awareness of the pitfalls in diagnosing breast cancers is important when creating a differential diagnosis for each breast lesion evaluated. This review will cover some of these scenarios to aid in the diagnostic process.

[Immunohistology in breast diagnostics : Strategies for efficient diagnostics]

Immunohistological examinations are useful for the histopathological diagnosis of breast carcinoma in various clinical situations. This review article aims to summarize the different immunohistological options. A distinction is made between diagnostic, prognostic, and predictive markers. Especially when a therapeutic decision results from the immunohistological expression pattern, a quantitative, quality-controlled, and validated diagnostic approach is essential.This is relevant, for example, for the classical markers ER, PR, and HER2, but also for Ki-67 and additional markers such as PD-L1. This article provides a practice-oriented summary of the most important immunohistochemical markers in routine breast cancer diagnosis and for the distinction of malignant findings from benign alterations or precursor lesions.

Application of a Low-Temperature Plasma Knife to Excise a Spindle Cell Tumor of the Nasal Cavity: A Case Report

To describe a rare case of spindle cell tumor in the nasal cavity of a young female, along with its successful surgical management using a low-temperature plasma knife. A 38-year-old female patient presented with a 6-month history of nasal blockage, hyposmia, and local tenderness. The patient denied a history of definite diagnosis or special treatment. A preoperative magnetic resonance imaging scan revealed the size and extent of the tumor in her nasal cavity. She underwent endoscopic surgery for the sinus using a low-temperature plasma knife. The procedure was performed without complications, and her symptoms resolved within 1 month. The postoperative pathology report suggested a spindle cell tumor in her nasal cavity. Nasal spindle cell tumor is rare and usually presents with no specific clinical symptoms, which should be taken into consideration during diagnosis. In this case, we demonstrate that the effectiveness and safety of sinus surgery can be improved and aided by a low-temperature plasma knife and nasal endoscopy.