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.
"SMA is a usual marker used for differential diagnosis of several tumors. Beside smooth muscle fibers, it also marks the fibroblasts and myofibroblasts being overexpressed in some mesenchymal tumors such as leiomyoma, leimyosarcoma, myofibroblastoma, inflammatory myofibroblastic tumor, and gastrointestinal stromal tumors with myogenic differentiation , , . A slight expression of SMA was also reported in spindle-shaped KS cells , , but its significance was not elucidated yet. "
[Show abstract][Hide abstract] ABSTRACT: Although several studies have been conducted regarding Kaposi sarcoma (KS), its histogenesis still remains to be elucidated. The aim of our study was to analyze the immunophenotype of Kaposi sarcoma and to present a hypothesis about the histogenesis of this tumor, based on a case series and a review of relevant literature.
In 15 cases of KSs diagnosed during 2000-2011, the clinicopathological features were correlated with the immunoexpression of c-Kit, SMA, CD34, CD31, vascular endothelial growth factor (VEGF), COX-2, c-KIT, smooth muscle antigen (SMA), and stem cell surface marker CD105.
Both CD105 and c-KIT rate of the spindle-shaped tumor cell positivity increased in parallel to the pathological stage. All cases displayed CD105 and weak c-KIT positivity in the endothelial cells. SMA, VEGF, and COX-2 were focally expressed in all cases. CD34 marked both endothelium and spindle-shaped tumor cells. No c-KIT expression was noticed in KS of the internal organs.
KS seems to be a variant of myofibroblastic tumors that originates from the viral modified pluripotent mesenchymal cells of the connective tissue transformed in spindle-shaped KS cells, followed by a mesenchymal-endothelial transition and a myofibroblastic-like differentiation. This paper mailnly showed that KS cannot be considered a pure vascular tumor.
PLoS ONE 08/2013; 8(8):e71530. DOI:10.1371/journal.pone.0071530 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Myofibroblastoma (MFB) is an uncommon benign mesenchymal tumor that may arise in several organs and tissue. Although most of reported cases were located in the breast, it is extremely rare, representing less than 1% of breast tumor. MFB has predominantly seen in elderly men, but some cases have been described in menopausal women. This lesion is a stromal tumor which has many morphologic variants including cellular, collagenized, epithelioid, palisaded, lipomatous, hemangiopericytoma-like, and infiltrant features. Even if its incidence has recently increased due to the mammary screening, only few cases have been reported in Literature and even less in young women. Physical examination discloses a solitary, unilateral, painless, freely movable, usual firm in consistency, non-tender nodule. Imaging investigations usually are not specific to establish the right diagnosis. Furthermore, findings from Fine-Needle Aspiration (FNA) may be confusing and nonspecific, making diagnosis of MFB possible only after surgical operation. Not evidence of malignant transformation, recurrence or distant metastasis after a follow-up period of 15 years have been reported in Literature when resection margins are free. Hereby the authors describe a rare case of breast MFB in a young woman.
Breast neoplasm, Myofibroblastoma, Premenopausal woman.
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