Male Breast Cellular Myofibroblastoma With a Rich Reticulinic Network

Abstract

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.

Rapidly growing myofibroblastoma of the breast diagnosed in a premenopausal woman: Management and review of the literature

“…MFB of the breast is a very rare clinical entity with only 80 cases reported in the literature so far [7]. Although it most commonly affects elderly men and postmenopausal women [2,11,16,17,19,23], the tumor can occur at any age.…”

“…Based on histological features several variants of MFB have been reported but without clinical implications [23]. The main morphologic variants include the collagenised or fibrous type, cellular, infiltrating, epithelioid, deciduoid, myxoid, rich-reticulinic and mixed subtypes [7,11]. The presence of excessive fatty component has very rarely been reported in MFB and may lead to a misinterpretation as other adipocytic stromal lesion especially in core biopsies [3].…”

Mesenchymal-to-Endothelial Transition in Kaposi Sarcoma: A Histogenetic Hypothesis Based on a Case Series and Literature Review

“…This marker is also present in the thyroid interfollicular cells [10] and can be overexpressed in cancer cells, in tumors such as gastrointestinal stromal tumors, inflammatory fibroid polyp or myofibroblastoma [11], [12].…”

“…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 [11], [12], [15]. A slight expression of SMA was also reported in spindle-shaped KS cells [7], [16], but its significance was not elucidated yet.…”

Inflammatory myofibroblastic tumor of the lumbar spinal canal

“…[22] Tumors such as Kaposi sarcoma or myofibroblastoma maintain CD34 positivity, [23] whereas it can be lost in other tumors during histogenesis.…”