Mammary-Type Myofibroblastoma: A Report of Two Cases

"Low-fat" intradermal spindle cell lipoma of the upper eyelid: a case report

Spindle cell lipomas are slow-growing, benign tumors composed of bland spindle cells, adipocytes, and collagen bundles. They are typically found on the posterior neck, shoulder, or upper back. Spindle cell lipomas represent only a small percentage of reported lipomatous tumor types. We report the case of a 90-year-old white man who presented with a solid mobile lesion on his right upper eyelid. Histopathological and immunohistochemical analysis of the lesion led to a diagnosis of a "low-fat," intradermal, spindle cell lipoma. This case underscores the importance of considering spindle cell lipoma in the differential diagnosis for atypical eyelid lesions.

Myofibroblastoma in the Liver: A Case Report and Review of Literature

Myofibroblastoma is a rare benign mesenchymal tumor first described in the breast. It is also known as mammary-type myofibroblastoma outside of the breast, more frequently located along the embryonic milk line. Exceptionally, myofibroblastoma can occur at visceral locations. We present a case of myofibroblastoma detected incidentally in the liver. A well-circumscribed mass, grossly measuring 6.2 cm in the liver parenchyma, was found on imaging studies. Histologically, the lesion is characterized by benign spindle cells in a hyalinized collagenous stroma, with positive staining for SMA and ER, focal positivity for CD34, negative for desmin, and loss of RB1. This rare tumor at such an unusual location makes it diagnostically challenging, especially on core biopsy of the lesion. To our knowledge, this is the second case of myofibroblastoma in the liver reported in the English literature and the first such case with a detailed pathology description.

Mammary‐type myofibroblastoma of the perineum: Typical or rare location?

Introduction

Mammary‐type myofibroblastoma is a rare benign tumor, mainly arising along the embryonal mammary ridge. We report a rare case of mammary‐type myofibroblastoma of the perineum.

Case presentation

A 37‐year‐old Japanese man presented with a 20 mm, progressively‐growing painless mass in the right perineum. Computed tomography showed a subcutaneous tumor with a strong contrast effect. Upon total resection, pathology showed a spindle‐cell tumor positive for desmin but negative for CD34. Further immunohistochemistry showed loss of Rb expression, leading to differential diagnosis. We could not evaluate the exact rarity of the perineal location due to categorization in past reports.

Conclusion

Due to the similarities between mammary and anogenital tissue, we suggest that tallying perineal and vulvar areas separately from the embryonic mammary ridge sites may be beneficial in gaining insight into the pathophysiology of this tumor.

Mammary-type myofibroblastoma of the thigh mimicking liposarcoma

Myofibroblastoma is a rare tumor that was originally described in the breast but has since been found in extra-mammary locations, where it been renamed mammary-type myofibroblastoma (MTM). We describe a case of MTM occurring in the anterior compartment of the thigh, which was initially interpreted as a possible a liposarcoma on MRI. Two subsequent biopsy samples and eventual excision revealed the tumor to have the characteristic pathology of MTM. This benign tumor, albeit rare, needs to be considered in the imaging differential diagnosis of fat containing deep soft tissue masses of the extremity.

A case of mammary-type myofibroblastoma of the inguinal region

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Mammary-type Myofibroblastoma of the Inguinal Region is very rare.

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Prognosis of this disease is good after surgical resection.

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The correct diagnosis and treatment is important.

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We think that it is useful to share knowledge widely about this disease.

Introduction

Myofibroblastoma is usually occurred in the breast and extra-mammary disease is rare.

Presentation of case

A 38-year-old man was admitted to our hospital for further examination of the left inguinal tumour, present and enlarging for 16 months. The tumor was 50 mm in diameter, well-circumscribed, firm, and painless. Ultrasonogaphy, computed tomography(CT) and magnetic resonance imaging (MRI) could not provide the definitive diagnosis. Surgical exploration confirmed a 50 mm tumour with a clear surface with a thin capsule. Complete excision was achieved. Histopathology confirmed the tumor had oval and spindle shaped fibroblastic cells with rich collagen deposition. It stained positive for ER, CD34, desmin and CD10 but negative for -smooth muscle actin and S-100. A mammary-type myofibroblastoma was diagnosed based on these results.

Discussion

An extra-mammary myofibroblastoma is very rare and first reported in 2001. Since then, over 160 cases have been reported. On immunohistochemistry, these lesions are characteristically positive for CD34 and desmin, with variable staining for α-smooth muscle actin. Once the diagnosis is made, regardless of size or location, this tumour behaves in a benign fashion after surgical excision reported so far.

Conclusion

This case is rare, but the correct diagnosis and treatment is important for good prognosis.

Imaging features of mammary-type myofibroblastoma of soft tissue: a case series with literature review

Mammary-type myofibroblastoma (MTM) is a rare, benign neoplasm that is histologically identical to myofibroblastoma of the breast, but occurring in an extramammary site. The masses have been reported in superficial and deep soft tissue sites and visceral locations with the inguinal area and lower extremities are the most common. Most previous reports of MTMs have concentrated on clinical and pathological findings, with very limited information regarding imaging characteristics. Here, we describe three cases of MTM diagnosed at our institution, with a focus on imaging findings. We compare our findings with previously reported cases. Although MTM is rare, radiologists should be aware of this benign diagnosis as imaging characteristics can mimic those of liposarcomas and atypical lipomatous tumor/well-differentiated liposarcoma. Unlike those tumor types, MTM virtually never recurs post-resection, even when there are positive margins. Biopsy is necessary for proper diagnosis and recommended as an initial step to avoid overly aggressive treatment.

Radiologic presentation of a myofibroblastoma of the adult male breast

We present the case of a 50-year-old male with bilateral gynecomastia who was incidentally found to have 0.8-cm subareolar mass on computed tomography. Mammographic and sonographic characteristics of the lesion are described as well as a brief historical review of myofibroblastoma, a rare mesenchymal tumor.

Mammary-type myofibroblastoma of the psoas

Mammary myofibroblastoma is a rare, benign, mesenchymal neoplasm that was first described in the breast in 1987. However, extra-mammary-type myofibroblastoma (MTMF) was not described until 2001 as a distinct entity. We report a case of extra-MTMF arising from the retroperitoneum, which was encountered in our clinic. We also completed a review of the literature using PubMed in patients with extra-MTMF.