Malignant phyllodes tumor with liposarcomatous components: a case report with cytological presentation

A Case of Phyllodes Tumor of the Breast with Mixed Liposarcoma: Case Report and Literature Review

Phyllodes tumors (PTs) account for less than 1% of breast tumors, and malignant PTs account for even less. Here, we described an unusual case of malignant PT with mixed liposarcoma (myxoid liposarcoma [MLP] and pleomorphic liposarcoma [PLP]). A 52-year-old woman discovered a small lump in her left breast. Twenty years later, the lump suddenly grew within 1 month. Mammography showed space-occupying lesions of the left breast. Histologically, the tumor was characterized by hypercellular stroma covering the epithelium and protrusion of the myoepithelium into the cyst to form a lobulated structure; regions of loose mucus and hypercellular structures alternated. A region of peripheral benign fibroadenoma was also observed, and many stellate and spindle cells or signet ring-like cells were identified in loose areas. Some areas showed a characteristic thin branching vascular pattern. In the cell-rich area, adipocytes and odd megakaryocytes were observed. Atypical mitotic figures were observed in the cell-rich and mucus areas (16 mitoses/10 high-power fields [HPF] and 2 mitoses/10 HPF, respectively). In the immunohistochemical analysis, a small number of tumor cells were positive for AE1/3 and vimentin, whereas all cells were negative for cytokeratin 34βE12, E-cadherin, p63, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and S-100, ruling out the possibility of metaplastic carcinoma. Interestingly, cyclin-dependent kinase 4, mouse double minute 2 (MDM2), and p16 were strongly positive in both loose mucus and cell-rich areas. However, the fluorescence in situ hybridization test results showed that MDM2 was not amplified. Combined with morphological characteristics, these findings supported that the tumor was a mixed malignant PT with MLP and PLP. Our patient did not receive radiation therapy, and after 47 months of follow-up, no recurrence or metastasis occurred. This case report serves to expand the morphologic spectrum of mixed malignant PT with liposarcoma.

Metaplastic Breast Cancer Masquerading as Liposarcoma of the Breast: A Case Report following Oncoplastic Treatment

Mammary liposarcoma is among the rarest of breast tumours. Here we report the presentation, macroscopic, microscopic, and immunohistochemical features of an extremely rare case of metaplastic carcinoma with extensive pleomorphic liposarcomatous differentiation. A 47-year-old woman presented with bilateral grade III breast ptosis and a 3 × 4 cm mass in the lower outer quadrant of the left breast. Mammography and ultrasound confirmed a well-defined mass. A core biopsy performed was diagnosed as pleomorphic liposarcoma. Microscopically, this was a well-defined, lobulated tumour comprising solid sheets of large pleomorphic and spindle cells with bizarre forms, vacuolated cytoplasm, and ample mitoses. Atypical lipoblasts were easily identifiable. Due to the strong, though patchy, cytokeratin expression, the diagnosis of metaplastic carcinoma with pleomorphic liposarcomatous differentiation was made. Extensive sampling, careful search for a biphasic pattern, ductal carcinoma in situ, and/or epithelial differentiation, and a panel of broad-spectrum cytokeratins are essential to establish the diagnosis.

A Diagnostic Approach to Fibroepithelial Breast Lesions

Fibroepithelial breast lesions encompass a heterogeneous group of neoplasms that range from benign to malignant, each exhibiting differing degrees of stromal proliferation in relation to the epithelial compartment. Fibroadenomas are common benign neoplasms that may be treated conservatively. Phyllodes tumors are relatively rare lesions, and classified as benign, borderline, or malignant based on histologic evaluation of various parameters. The diagnostic interpretation of "gray-zone" fibroepithelial lesions often imposes formidable demands on a pathologist's skills. This article offers practical recommendations for the diagnostic workup of these lesions, including the appropriate utilization of ancillary investigations and the approach to core needle biopsies.

A Giant Phyllodes Tumor of the Breast

Phyllodes tumors of the breast are rare, accounting for less than 1% of the breast tumors. They are mostly seen in women between 45 and 49 years old. These are fast growing tumors with a large spectrum of behavior (from benign to metastatic) and can resemble fibroadenomas. Correct diagnosis mostly through core needle biopsy is important to decide whether a surgical excision has to be done. Here we report a case of a 57-year-old woman with a fast growing, ulcerated tumor in the left breast. Core needle biopsy suggested a malignant phyllodes tumor with heterologous liposarcomatous differentiation. Treatment with total mastectomy and adjuvant radiotherapy followed. Primary treatment is always surgery, whether radiotherapy or chemotherapy has to follow remains uncertain. There is a high-recurrence rate, especially when the surgical margins are narrow.

Fine-needle sampling in malignant phyllodes tumors: Clinicopathologic study of 22 cases seen at the Institut Curie

The preoperative cytological diagnosis of malignant phyllodes tumor (MPT) is challenging due to the heterogeneity of its clinical, radiological, and morphological presentation. To better define the cytopathological characteristics of MPT, we reviewed 22 examples seen at the Institut Curie. The original cytologic diagnosis was benign breast tumor in four cases (18.2%), suspicious in seven cases (31.8%) (low-grade phyllodes tumor in six cases needing histological evaluation, suspicious of sarcoma in one case), and malignant in 11 cases (50%). Smears were composed of different proportions of clusters of epithelial cells (68.2%), phyllodes fragments (31.8%), spindle cells within stromal tissue (31.8%), isolated spindle-shaped or round cells (45.5%), and bipolar naked nuclei (22.7%). Giant cells and mitotic figures were also occasionally seen. The cytological findings on smears were correlated with histopathological observations. One of the difficulties to reach an accurate cytological diagnosis for MPT is the frequent overwhelming of clearly malignant sarcomatous cell by the presence of largely predominant clusters of epithelial cell.

Leiomyosarcoma of the breast: a difficult diagnosis on fine-needle aspiration biopsy

Leiomyosarcoma of the breast is rarely encountered in fine-needle aspiration (FNA) cytologic material. We report a case of primary leiomyosarcoma of the breast in a 52-yr-old female. Aspiration cytology showed large, dissociated round to spindle cells with abundant vacuolated cytoplasm, pleomorphic nuclei, prominent nucleoli, and occasional intranuclear cytoplasmic invaginations. Mitotic figures, osteoclast-like giant cells, and stromal fragments were identified. A diagnosis of malignant neoplasm representing either a sarcoma, a poorly differentiated carcinoma, or a metaplastic carcinoma was made. The patient underwent a wide excision of the lesion after negative work-up. Histologic examination and immunohistochemical studies established the diagnosis of leiomyosarcoma. This case is presented here because we feel that, although FNA cytology with eventual ancillary studies is a valuable diagnostic tool to evaluate any breast mass, malignant spindle cell neoplasms of the breast still represent a diagnostic challenge for the cytopathologist. Recognition of all cytologic features of leiomyosarcoma may help to formulate a correct diagnosis.

Malignant phyllodes tumor of the breast: review of the literature and case report of stromal overgrowth

Cystosarcoma phyllodes constitutes only 0.3-0.9% of all breast tumors. The term "sarcoma" was initially used because of its fleshy appearance, a more modern term is Phyllodes tumor (PT). The behavior of PT constitutes a spectrum from benign and locally recurrent to malignant and metastatic. In a general surgical series, 6.2% of the tumors were malignant. The microscopic appearance of PT is that of epithelial elements and connective tissue stroma. Malignancy is determined by characteristics of the stroma. The metastatic spread of malignant PT is mainly hematogenous to lung, with infrequent lymphatic involvement. Wide local excision with 2 cm margins is the treatment of choice. In 20% of both benign and malignant cases, PT will locally recur. There is no proven benefit of radiation or chemotherapy, although radiotherapy may be useful in selected cases. We present a case of a sarcomatous overgrowth in a malignant phyllodes tumor involving multiple histologic types.