Lipomatous variant of myofibroblastoma with epithelioid features: a rare and diagnostically challenging breast lesion

Epithelioid myofibroblastoma of the breast: A case report and review of the literature

INTRODUCTION

Mammary myofibroblastoma (MFB) is a rare tumour. Its clinical and pathologic characteristics have been only sporadically described. A case of epithelioid variant of MFB is reported with the diagnostic tips, the differential diagnoses, and a discussion on the possible pathogenesis.

PRESENTATION OF CASE

A 74 year-old woman presented with a painless nodule in the left breast. Core needle biopsy (CNB) revealed a tumour primarily composed of epithelioid cells. Despite epithelioid appearance of the tumour cells, ductal/lobular components were absent within the tumour. As cell lineage of the epithelioid cells could not be determined with CNB, lumpectomy was performed to obtain definitive diagnosis and, at the same time, to remove the lesion. Histologically, the tumour consisted of multiple epithelioid cell nests that were spread over fibrous stroma infiltrated with adipose tissue. Spindle cells were also present, but they were fewer than epithelioid cell clusters. Occasionally, the tumour cells showed nuclear atypia. It was difficult to determine whether this tumour was benign or malignant solely with Hematoxylin-eosin stain. However, with the aid of immunohistochemical analyses, we could make a histodiagnosis of epithelioid subtype of myofibroblastoma.

DISCUSSION

The differential diagnoses of epithelioid MFB include ductal, lobular, metaplastic carcinomas and mesenchymal tumours. Comprehensive knowledge of classic and variant MFB is necessary for the correct diagnosis.

CONCLUSION

Pathologic diagnosis of epithelioid variant of MFB requires careful evaluation of histology and the use of a panel of immunohistochemistry. Female phenotype of breast stroma may play a role in the pathogenesis of MFB.

First Vacuum-Assisted Excision of a Breast Myofibroblastoma

A 52-year-old lady was seen in the breast clinic after an 8 mm lesion was found in her left breast on screening mammogram. Clinical examination was normal. The left breast mammogram showed an 8 mm rounded density posteriorly in the inner half of breast and ultrasound also showed a 7 mm, well-defined ovoid echogenic lesion (R3, U3). Biopsy confirmed the lesion was fibro-fatty tissue containing a diffuse infiltrate of lymphoid cells macroscopically (B3/4)—findings in line with a diagnosis of a myofibroblastoma. A myofibroblastoma is a rare benign mesenchymal tumour comprising of spindle cells. Most breast myofibroblastomas described in the literature have been excised by wide local excision. In this patient's case, a vacuum-assisted technique was discussed and suggested at the multidisciplinary meeting. It was excised using ultrasound-guided Vacora® breast biopsy system. The lesion was completely excised with the encore biopsy measuring 24 × 17 mm. This is the first documented case of such a technique for the excision of a breast myofibroblastoma. There still is uncertainty about breast myofibroblastomas, their aetiology, associations, and how they are best investigated. Regarding management, vacuum-assisted technique, being less invasive and cheaper than local excisions, is adequate for small lesions.

Lipomatous tumors of the breast: A contemporary review

Breast tumors with lipomatous or liposarcomatous components are infrequently encountered, but can be a source of diagnostic difficulty if the context of the fatty differentiation is not recognized. Among the true adipocytic tumors, lipoma is the most common lipomatous tumor arising in the breast. Several mammary spindle cell tumors may show adipocytic differentiation, including fibroepithelial tumors and myofibroblastoma. Liposarcomatous components most often arise in malignant phyllodes tumors, as opposed to primary liposarcomas of the breast which are believed to be uncommon. This article will review the spectrum fat-containing tumors of the breast with an emphasis on differential diagnosis and insights from recent molecular studies.

Intraocular myofibroblastoma in an infant: a case report

BACKGROUND

Myofibroblastoma is a benign tumor composed of spindle cells and bands of hyalinized collagen. Intraocular myofibroblastoma in infancy is rarely encountered.

CASE PRESENTATION

The present study reports the case of a 4-month-old female baby with intraocular myofibroblastoma. She was suspected as corneal perforation due to the rupture of a corneal neoplasm in the right eye. The anterior segment was also involved according to the Color Doppler ultrasonography. A surgical exploration was performed and the protuberant part of the mass was resected. Conventional HE staining showed numerous spindle-shaped cells with bands of collagen beneath multilayers of well-differentiated corneal epithelia. Immunohistochemical staining demonstrated the tumor cells were strong positive for vimentin and smooth muscle actin, while negative for S-100 protein. The mass was confirmed as myofibroblastoma. After 12 month follow-up, there was no apparent growth of the tumor.

CONCLUSIONS

Myofibroblastoma is a very rare type of intraocular neoplasm, which may have complicated manifestation and could be misdiagnosed as dermoid or Peter's anomaly. Histopathological and immunohistochemical staining is crucial to form a precise diagnosis.

Myofibroblastoma of the female breast with admixed but distinct foci of spindle cell lipoma: a case report

Mammary myofibroblastoma (MFB) is a rare benign spindle neoplasm that affects both sexes with a male predominance. It can exhibit a wide range of histological patterns. We report a case of epithelioid/spindle MFB of the female breast with admixed, but distinct, foci of spindle cell lipoma. Whilst all the spindle cells within the tumour expressed CD34, AR, ER, BCL2, and CD10, only those within the myofibroblastoma expressed desmin and only those within the lipomatous areas expressed S100. This finding, to our knowledge, is a novel one that has not been reported before.

Hyperechoic lesions of the breast: radiologic-histopathologic correlation

OBJECTIVE

Breast ultrasound is helpful in the characterization of masses to differentiate benign from malignant disease. The internal echotexture of a mass is an important ultra-sound feature in breast diagnostic workup. This article reviews the imaging and histopathology findings of benign and malignant hyperechoic masses to better recognize these conditions.

CONCLUSION

Hyperechoic masses are frequently benign, including hematoma, fat necrosis, abscess, and benign neoplasm. Malignant hyperechoic lesions include invasive ductal and invasive lobular carcinoma, lymphoma, and sarcoma. Understanding lesion echotexture in the context of clinical and mammographic findings will help establish appropriate diagnoses for hyperechoic masses.

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.