Leiomyoma of the Nipple

Mesenchymal Tumors of the Breast: Fibroblastic/Myofibroblastic Lesions and Other Lesions

Mesenchymal breast tumors are a rare and diverse group of tumors that present some of the most challenging cases for multidisciplinary breast cancer teams. As a result of overlapping morphologies and a lack of large-scale studies on these tumors, practices are often heterogeneous and slow to evolve. Herein, we present a non-systematic review that focuses on progress, or lack thereof, in the field of mesenchymal breast tumors. We focus on tumors originating from fibroblastic/myofibroblastic cells and tumors originating from less common cellular origins (smooth muscle, neural tissue, adipose tissue, vascular tissue, etc.).

Leiomyoma of the breast parenchyma: a case report and review of the literature

INTRODUCTION

Benign tumors are often seen in breast screening examinations. However, the differential diagnosis is not always simple because of radiological similarity between the different benign lesions.

CASE REPORT

We present a rare case report of leiomyoma of the breast parenchyma in a 68-year-old asymptomatic patient. The mammographic and ultrasonographic findings were similar to those observed in benign lesions.

CONCLUSION

The histopathological diagnosis requires careful differentiation from lesions that have smooth muscle proliferation, especially leiomyosarcoma. The most commonly performed treatment is resection of the lesion with free margins. Although breast leiomyoma is rare, it should be considered among the differential diagnoses for breast nodules of benign appearance. Resection with safety margins proved to be the only treatment needed.

Myofibroblastic, fibroblastic and myoid lesions of the breast

Myofibroblastic, fibroblastic and/or myoid lesions are rare in the breast but comprise the majority of mammary mesenchymal spindle cell lesions. Whereas most have similar features to their counterparts at extramammary sites, pseudoangiomatous stromal hyperplasia is considered a breast-specific myofibroblastic proliferation on the same spectrum as myofibroblastoma. Other lesions with myofibroblastic/fibroblastic differentiation include fibromatosis and nodular fasciitis, as well as more aggressive tumors such as the rarely reported myofibrosarcoma, inflammatory myofibroblastic tumor and fibrosarcoma. Lesions with myoid differentiation include benign leiomyoma, myoid hamartoma and leiomyomatous myofibroblastoma, but primary leiomyosarcoma and rhabdomyosarcoma may also rarely arise in the breast. Furthermore, fibroepithelial lesions and metaplastic carcinomas can demonstrate myoid metaplasia. Diagnosis can be challenging, particularly on core biopsy, but benign lesions with or without recurrence potential must be distinguished from more aggressive tumors, especially metaplastic carcinoma and phyllodes tumors. This article will review lesions with myofibroblastic, fibroblastic and myoid differentiation in the breast, with special emphasis on differential diagnosis.

A 35-year-old woman presenting with an unusual post-traumatic leiomyoma of the nipple: a case report

Introduction

Leiomyoma of the mammary papilla is one of the most uncommon nipple tumors with only 50 cases reported in the literature until now. To the best of our knowledge we present the first report of a nipple leiomyoma that originated from a traumatic abrasion caused by breastfeeding.

Case presentation

A 35-year-old healthy Caucasian female with a cauliflower-like tender and pink nodular mass that was approximately 10mm in diameter presented to our out-patients department. The patient suggested that the mass originated from a traumatic abrasion caused by breastfeeding three years ago and it has been slowly growing ever since.

An excision biopsy was performed. The histological and immunohistochemical examination confirmed the diagnosis of leiomyoma. There were no postoperative complications or any sign of local recurrence four years postoperatively.

Conclusions

Leiomyoma of the mammary papilla is a rare benign neoplasm that usually appears as a solid tender nodule. Differential diagnosis comprises breast carcinoma, leiomyosarcoma and myoid hamartoma. The recommended treatment is complete excision of the tumor with histologically confirmed tumor-free margins otherwise recurrence is possible. A detailed history of the patient’s disease can reveal the original etiology. This is an original case report that will have particular interest to plastic surgeons, dermatologists, and pathologists. The pathogenetic mechanism was trauma of the nipple. According to our review of the literature this particular information has never been reported and we think that it may advance our knowledge of this very infrequent tumor.

Two cases of male nipple leiomyoma: idiopathic leiomyoma and gynecomastia-associated leiomyoma

We describe 2 cases of male nipple leiomyoma. A 70-year-old man had a painful subcutaneous tumor on his left nipple of 6 months duration. Histopathology disclosed dermal spindle cells with oval-shaped nuclei forming interlacing bundles with irregular pattern. Glandular elements were absent. The spindle cells were positive to α-smooth muscle actin, desmin, and vimentin. Estrogen receptor (ER) and progesterone receptor (PrR) were negative. We diagnosed this case as male leiomyoma of the nipple. Another patient was a 61-year-old man with gynecomastia induced by spironolactone of 6 months duration. He also had a painful nodule on his left nipple and histopathology disclosed spindle-shaped tumor cells as in the previous patient. The tumor was accompanied by glandular elements in the deep dermis and subcutaneous tissue, which showed apocrine secretion and were positive for α-smooth muscle actin, ER, and PrR. These glandular elements were interpreted as mammary gland. But ER and PrR stain did not show positive results for leiomyoma in the upper dermis. To the best of our knowledge, this is the first report of male idiopathic and gynecomastia-induced leiomyoma with ER and PrR staining.

Leiomyoma of the nipple diagnosed by MRI

Leiomyoma of the nipple is a rare, benign, non-epithelial tumor that is thought to arise from smooth muscle fibers in the subareolar tissue of the breast. We report an unusual case of leiomyoma of the nipple in a 32-year-old woman in whom the diagnosis was made by ultrasound-guided core needle biopsy. She came to our hospital complaining of a recently enlarged nipple with discharge and erosion in the region of the left nipple-areolar complex. This mass was evaluated by mammography, ultrasonography, and magnetic resonance imaging (MRI). To the best of our knowledge, this is the first case of a leiomyoma of the nipple examined by MRI. MRI showed an oval mass with circumscribed margins that appeared as an intermediate signal intensity on both T1- and T2-weighted images. A dynamic MRI study showed a rim-enhancing oval mass with delayed persistent enhancement. Ultrasound-guided core needle biopsy revealed spindle cell proliferation consistent with leiomyoma of the nipple.

[Hyperkeratotic lesion of the nipple revealing cutaneous leiomyoma]

BACKGROUND

Leiomyoma of the nipple and areola is a rare benign neoplasm. We report the case of a patient with leiomyoma of the nipple presenting as a hyperkeratotic plaque.

OBSERVATION

A 23-year-old patient presented with a five year history of a papillomatous, hyperkeratotic, painful plaque originating in her right nipple. Histological examination of a punch biopsy showed hyperkeratosis of the epidermis with dilatation of the lymphatic vessels within the dermis. Surgical excision revealed a proliferation of smooth muscle fibres, leading to diagnosis of leiomyoma.

DISCUSSION

The clinical and histological features were initially consistent with idiopathic naevoid hyperkeratosis of areola. However, associated pain is uncommon in idiopathic lesions. This unusual feature led us to surgical excision enabling the diagnosis of leiomyoma. A hyperkeratotic lesion of the nipple may be associated with benign or malignant neoplasms, hamartoma or chronic dermatoses, or it may be idiopathic. In the present case, the hyperkeratotic lesion revealed subareolar leiomyoma. This is an uncommon clinical presentation not previously seen in medical observations, since leiomyoma usually presents as a firm, painful lump in the subareolar region.