Smooth muscle myosin heavy chain and caldesmon expression in the anterior vaginal wall of women with and without pelvic organ prolapse

Abstract Background.—The histopathologic features of dermatofibroma vary remarkably, and this diversity may occasionally cause problems in differentiating between benign and malignant mesenchymal lesions, including smooth muscle neoplasms. Immunohistochemical stains are sometimes necessary to clarify the histogenesis of a lesion. Objective.—To evaluate dermatofibromas for expression of desmin and smooth muscle myosin heavy chain (SM-MHC) antigens, which are commonly used as evidence of smooth muscle differentiation. Methods.—We studied 100 consecutive cases of dermatofibroma using hematoxylin-eosin–stained sections and immunoperoxidase staining with antibodies against desmin, SM-MHC, and smooth muscle actin. Results.—We found focal positivity for desmin in 9 cases, and in 2 of these cases, at least 10% of lesional cells showed strong expression. We found focal staining for SM-MHC in 10 cases, and in 2 of these cases, at least 10% of the lesional cells were positive. Regions positive for desmin and/or SM-MHC did not show definite histologic features of myogenous differentiation on hematoxylin-eosin–stained sections. All dermatofibromas expressing desmin and SM-MHC were also strongly positive for smooth muscle actin. Conclusions.—About 10% of dermatofibromas show focal expression of desmin and SM-MHC, and this expression may be present in up to 10% to 15% of lesional cells. Thus, in dermal spindle cell lesions, focal expression of these muscle antigens, like that of smooth muscle actin, is not diagnostic of a smooth muscle tumor.

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Smooth muscle myosin heavy chain

Leong's Manual of Diagnostic Antibodies for Immunohistology ◽

10.1017/9781139939508.205 ◽

2016 ◽

pp. 429-430

Keyword(s):

Smooth Muscle ◽

Myosin Heavy Chain ◽

Heavy Chain ◽

Smooth Muscle Myosin ◽

Muscle Myosin

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Changes in muscularis propria of anterior vaginal wall in women with pelvic organ prolapse

European Journal of Histochemistry ◽

10.4081/ejh.2016.2604 ◽

2016 ◽

Vol 60 (1) ◽

Cited By ~ 6

Author(s):

A. Vetuschi ◽

A. D'Alfonso ◽

R. Sferra ◽

D. Zanelli ◽

S. Pompili ◽

...

Keyword(s):

Risk Factors ◽

Smooth Muscle ◽

Pelvic Organ Prolapse ◽

Smooth Muscle Cells ◽

Muscularis Propria ◽

Muscle Cells ◽

Pelvic Organ ◽

Vaginal Wall ◽

Anterior Vaginal Wall ◽

Collagen Iii

The objective of this study was to evaluate the morphological and immunohistochemical alterations of tissue removed from the upper third of anterior vaginal wall in a sample group of the female population presenting homogenous risk factors associated with Pelvic Organ Prolapse (POP). The case study consisted of 14 patients with POP and there were 10 patients in the control group. Patient selection was carried on the basis of specific criteria and all of the patients involved in the study presented one or more of the recognized POP risk factors. Samples were taken from POP patients during vaginal plastic surgery following colpohysterectomy, and from control patients during closure of the posterior fornix following hysterectomy. Samples were processed for histological and immunohistochemical analyses for Collagen I and Collagen III, α-Smooth Muscle Actin (α-SMA), Platelet-Derived-Growth-Factor (PDGF), matrix metalloproteinase 3 (MMP3), Caspase3. Immunofluorescence analyses for Collagen I and III and PDGF were also carried out. In prolapsed specimens our results show a disorganization of smooth muscle cells that appeared to have been displaced by an increased collagen III deposition resulting in rearrangement of the muscularis propria architecture. These findings suggest that the increase in the expression of collagen fibers in muscularis could probably due to a phenotypic switch resulting in the dedifferentiation of smooth muscle cells into myofibroblasts. These alterations could be responsible for the compromising of the dynamic functionality of the pelvic floor.

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