Cytological diagnostic clues in fine needle aspiration of breast myofibroblastoma: A case report

A case of mammary myofibroblastoma diagnosed with cytomorphological, cell block and immunohistochemistry findings

Myofibroblastoma (MFB) is a rare benign spindle cell tumor originating from myofibroblasts in the breast stroma. MFB typically presents as a slow-growing, well-circumscribed, solitary mass ranging from 1 to 4 cm in size. It has been reported in adults, and frequently seen in older males and in postmenopausal females. The lesion is composed of stromal cells showing fibroblastic and myofibroblastic differentiation at the morphological, immunohistochemical and ultrastructural levels. To date, the literature includes only about 24 MFB cases confirmed via fine-needle aspiration and cytological evaluation. Here, we present a patient with MFB that was diagnosed via conventional smear slides and cell block, in addition to immunohistochemical analysis.

A case report of a mammary myofibroblastoma in a male and literature review of radiologic and pathologic features of breast myofibroblastoma

We reported a 65-year-old male with a benign mammary myofibroblastoma. This report shows that not all masses of male breast are malignant. To differentiate benign masses from malignant neoplasms, careful preoperative diagnosis should be performed. Preoperative diagnosis of the tumor prevents placing a huge financial and mental burdens on patients.

Cytological Findings in Benign Phyllodes Tumors

OBJECTIVE

Phyllodes tumors are fibroepithelial breast lesions with many cytological and histopathological similarities to fibroadenomas. The aim of this study was to investigate cytological findings in benign phyllodes tumors.

STUDY DESIGN

Seventy-six histologically proven cases of benign phyllodes tumors were selected from 1982 to 2017. Cytological criteria, including cellularity, the number and shape of epithelial clusters, the shape and number of stromal fragments, and the presence of atypia, were evaluated.

RESULTS

Cytological slides were hypercellular and showed dimorphic populations of cells. The epithelial clusters were moderate in amount and had a bonsai-like configuration. The stromal fragments consisted of oval-to-spindle shaped cells with preservation of the cytoplasm. Some popcorn-like cells and intranuclear inclusions in stromal cells and deposition of pinkish and amorphous material at the border of the stromal fragments were also noted in the stromal cells.

CONCLUSION

Stromal hypercellularity and large amounts of stromal fragments, the presence of bonsai-like epithelial clusters, and deposition of amorphous pinkish material at the border of the stromal fragments, as well as newly observed findings including the presence of intranuclear inclusions and popcorn-like nuclei in the stromal cells, can aid in the diagnosis of phyllodes tumors.

Mammary Myofibroblastoma with Unusual Morphological and Immunohistochemical Features

Mammary myofibroblastoma (MFB) is a rare mesenchymal tumor, derived from mammary stromal fibro/myofibroblasts, which has various morphological features and characteristic immunohistochemical staining. The epithelioid morphologic variant is defined, accordingly, as a proliferation of exclusively or predominantly (>50%) epithelioid cells, variably embedded in a myxoid to fibrous stroma. These histological and cytological features may pose a diagnostic challenge mainly with metaplastic carcinoma and invasive lobular carcinoma of the breast. Thus, immunohistochemical staining by myofibroblastic markers is helpful for confirming diagnosis. Herein, we present a case of MFB in a 43-year-old female. This case report emphasizes the role of immunohistochemistry as gold standard in the diagnosis of MFB. This case is also being presented because of its unusual radiologic findings, its epithelioid histologic variant mimicking malignancy, and its uncommon immunohistochemical phenotype.

Cytological Features of Palisaded Mammary-Type Myofibroblastoma

Palisaded mammary-type myofibroblastoma is a rare variant of benign stromal spindle cell tumor whose histological features are well known. Nevertheless, no cytological features have been reported to date. In this article, we describe the cytological features of a case of palisaded mammary-type myofibroblastoma in which a preoperative fine needle aspirate was obtained. Smears were moderately cellular, characterized by clusters of spindle cells, disposed in a parallel fashion and immersed in myxoid background. Although the lesion is rare, it is worth distinguishing from benign and malignant spindle cell tumors.

Mammary-type myofibroblastoma of the right thigh: a case report and review of the literature

Introduction

Mammary-type myofibroblastoma of the soft tissue is a very rare, benign, mesenchymal neoplasm with myofibroblastic differentiation. To date, 20 cases of extra-mammary myofibroblastoma have been described in literature. To the best of our knowledge, this is the largest extra-mammary myofibroblastoma described in the literature, and the first case reported in this location.

Case presentation

A 50-year-old Pakistani man presented with a long history of a painless, huge lump on his right thigh. His clinical examination showed normal-looking skin and there was no inguinal lymphadenopathy. The mass was excised with a clinical impression of soft tissue sarcoma. Gross examination showed a huge, well-circumscribed soft tissue mass measuring 34cm in its largest dimension and weighing approximately 13kg. It was partially covered by fat tissue. Histologically, the lesion was composed of a haphazard arrangement of bland spindle-shaped cell fascicles in a thick collagenous and myxoid background. The neoplastic cells showed diffuse and patchy positivity for CD34 and desmin, respectively. No recurrence was seen following surgical excision over a follow-up period of five months.

Conclusions

Mammary-type myofibroblastoma of the soft tissue is a benign soft tissue neoplasm, and no malignant behavior and/or recurrence after surgical resection has been described, regarding its size and location. As an extremely rare tumor, the correct diagnosis and prompt management is important, and requires careful clinical and pathological workup to rule out the possibility of a malignant neoplasm.

Inconclusive or erroneous fine-needle aspirates of breast with adequate and representative material: a cytologic/histologic study

Adequately cellular and representative fine-needle aspirates (FNAs) of breast have a high diagnostic accuracy. There is, however, a recognized category designated as "gray zone" where a definitive diagnosis cannot be reached. We reviewed our experience in this category to identify useful diagnostic parameters. Twenty-four such FNAs with surgical follow-up were retrieved from AUBMC files (2003-2009). Cytology slides were reviewed blindly. All cases were females, 29-73 years. There were three erroneous and 21 inconclusive diagnoses. The majority (15) was invasive adenocarcinomas: two cribriform, four tubular, one lobular, and eight not otherwise specified. The remaining cases were papillary and fibroepithelial tumors (three each), ductal carcinoma in situ, cribriform (two), and one adenomyoepithelioma (AME). Useful diagnostic features included: (1) Biphasic cell population with focal nuclear atypia and intranuclear and cytoplasmic vacuolar inclusions (AME). (2) Complex clusters of epithelial cells with cribriform architecture (cribriform carcinoma). (3) Rigid tubular epithelial structures with abrupt change in diameter, ending in pointed tips with abnormal branching (tubular carcinoma). (4) Cellular stromal fragments (fibroepithelial tumors). (5) Papillary fibrovascular cores, columnar cells, and three-dimensional papillary epithelial fragments (papillary tumors). Myoepithelial cells classically described in benign aspirates were not always a discriminatory factor. The "gray zone" in breast FNA is usually due to overlapping cytologic features of some benign and malignant lesions. Useful distinguishing cytologic features are described.

Indeterminate and erroneous fine-needle aspirates of breast with focus on the 'true gray zone': a review

OBJECTIVE

To review our experience and the literature on inconclusive/erroneous fine-needle aspirates (FNAs) of breast with the focus on the 'true gray zone'. To describe the cytology, differential diagnosis, pitfalls and limitations of common and rare lesions.

STUDY DESIGN

We conducted a literature search focusing on breast FNAs with statistical data of C3 and C4 categories including false-positive and false-negative cases. Similar data from 2003 to 2009 was obtained from our institution.

RESULTS

C3 and C4 categories account for 3-17% of breast FNAs. Contributing factors are technical difficulties, inexperienced pathologists interpreting FNAs of breast and overlap of cytologic features of certain benign and malignant conditions; this last, 'true gray zone' accounts for 2% of cases. Fibroadenoma, proliferative breast lesions, gynecomastia, infiltrating and in situ low-grade adenocarcinomas and tubular, cribriform, lobular and mucinous carcinomas are the most common problematic lesions. Granular cell tumor, adenomyoepithelioma, pregnancy-related lesions, fat necrosis, inflammatory and radiation changes, adenoid cystic carcinoma, spindle-cell lesions and Phyllodes tumor are less common.

CONCLUSION

Inconclusive/erroneous FNAs of breast due to the 'true gray zone' are rare. Most are due to the overlapping cytologic features of some benign and malignant conditions. Practical features that may help arrive at the correct diagnoses are elucidated.

Male breast cellular myofibroblastoma with a rich reticulinic network: case report

Myofibroblastoma is a rare mesenchymal tumor located not only in breast but also in extramammary sites. This is the 79th case of breast myofibroblastoma reported in the literature. This tumor presents a great variety of morphological features, which increase the difficulty of differential diagnosis. The authors report a breast myofibroblastoma diagnosed in a 73-year-old male. The article discusses a bilateral gynecomastia and a palpable right breast well-defined tumor, without calcifications on mammography, which was surgically removed. Macroscopically, a well-circumscribed uncapsulated nodule was seen with lobular arrangement on cut section, and microscopically, a nodule with pushing borders and a connective pseudocapsule was seen. The spindle cells were arranged in fascicular clusters, with focally collagen bundles and a rich reticulinic network stained black with Gömöri impregnation. Immunohistochemically, the tumor cells were marked by vimentin, CD34, desmin, and smooth muscle antigen and did not express cytokeratin, S-100 protein, CD99, CD10, and factor VIII-related antigen. More than 90% of the cells expressed estrogen receptor. No recurrences were reported 2 years after surgical excision. This case is a variant of cellular myofibroblastoma, with a rich reticulinic network and scanty collagen bands.