Masson Trichrome Stain Helps Differentiate Myofibroma from Smooth Muscle Lesions in the Head and Neck Region
ABSTRACT Myofibromas are well described in the head and neck region, but differentiating them from smooth muscle lesions is still difficult using smooth muscle immunohistochemical stains. This study evaluated the usefulness of the Masson trichrome stain in differentiating myofibromas from smooth muscle lesions in the head and neck region.
Samples of 11 oral myofibromas, two leiomyomas, one angioleiomyoma, and one smooth muscle hamartoma were retrieved from our archives. Immunohistochemistry and Masson trichrome stains were performed on tissue sections of these lesions.
All 11 oral myofibromas, seven from male patients and four from female patients, were solitary myofibromas. The patients' mean age at diagnosis was 32.8 years. Oral myofibromas occurred most commonly on the gingiva (four cases) and in the mandible (three cases). With the Masson trichrome stain, the smooth muscle cell cytoplasm was stained red, while the collagenous fibrous tissue was stained blue. Myofibromas and smooth muscle lesions demonstrated different characteristic patterns with the Masson trichrome stain. Myofibromas were composed of a much more collagenous stroma intermixed with the spindle cells. Thick fibrous bundles with random, irregularly intersecting angles were prominent in myofibromas. Smooth muscle lesions showed only minimal delicate fibrous tissue surrounding the smooth muscle cells and in the septa between the smooth muscle masses. On low-power view, red masses of smooth muscle tumor surrounded by blue fibrous tissue were observed.
The Masson trichrome stain can be a useful tool to differentiate myofibromas from smooth muscle lesions, but immunohistochemical methods to rule out other spindle cell lesions are still needed.
- SourceAvailable from: You Kyoung Lee
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- "Sections of lung tissue (4 μm thick) were fixed in Bouin's solution, stained for 1 h at 56°C, washed in tap water for 5 min at room temperature, and stained for 10 min with Weigert's iron-hematoxylin. Masson's thrichrome stain was done as previously described . The total amount of soluble collagen was assessed using a Sircol Collagen Assay Kit according to the manufacturer's instructions (Biocolor, Carrickfergus, Northern Ireland, UK). "
ABSTRACT: No effective treatment for acute lung injury and fibrosis currently exists. Aim of this study was to investigate the time-dependent effect of bone marrow-derived mesenchymal stem cells (BMDMSCs) on bleomycin (BLM)-induced acute lung injury and fibrosis and nitric oxide metabolites and inflammatory cytokine production. BMDMSCs were transferred 4 days after BLM inhalation. Wet/dry ratio, bronchoalveolar lavage cell profiles, histologic changes and deposition of collagen were analyzed. Nitrite, nitrate and cytokines were measured weekly through day 28. At day 7, the wet/dry ratio, neutrophilic inflammation, and amount of collagen were elevated in BLM-treated rats compared to sham rats (p = 0.05-0.002). Levels nitrite, nitrate, IL-1beta, IL-6, TNF-alpha, TGF-beta and VEGF were also higher at day 7 (p < 0.05). Degree of lymphocyte and macrophage infiltration increased steadily over time. BMDMSC transfer significantly reduced the BLM-induced increase in wet/dry ratio, degree of neutrophilic infiltration, collagen deposition, and levels of the cytokines, nitrite, and nitrate to those in sham-treated rats (p < 0.05). Fluorescence in situ hybridization localized the engrafted cells to areas of lung injury. Systemic transfer of BMDMSCs effectively reduced the BLM-induced lung injury and fibrosis through the down-regulation of nitric oxide metabolites, and proinflammatory and angiogenic cytokines.Respiratory research 02/2010; 11(1):16. DOI:10.1186/1465-9921-11-16 · 3.38 Impact Factor
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ABSTRACT: Angioleiomyoma is an uncommon benign soft tissue tumor usually found in the lower extremities and rarely observed in oral tissues. It is microscopically characterized as a proliferation of smooth muscle cells intermingled with abundant vascular channels. Oral angioleiomyomas affect mostly the lips, palate, buccal mucosa and tongue, and appears as a submucosal painless nodule. Upper lip is seldom affected and only few cases have been reported. We report three additional cases of angioleiomyoma affecting the lips of elderly patients. All lesions were asymptomatic and presented as submucosal nodules of approximately 1cm. Microscopic analysis on H&E sections revealed similar pattern in all cases, showing well-circumscribed and encapsulated tumors characterized by proliferation of smooth muscle cells and large amount of wide vascular spaces of varying sizes. Most tumor cells were immunoreactive for a-smooth muscle actin, desmin and HHF-35. CD34 was also positive on the endothelial cells. All patients were surgically treated and no recurrence was observed so far. The oral pathologists and clinicians should consider this entity when assessing nodular lesions on upper lip.Medicina oral, patologia oral y cirugia bucal 07/2011; 16(4):e482-7. DOI:10.4317/medoral.16.e482 · 1.10 Impact Factor
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ABSTRACT: To report a case of coexisting irritation fibroma and myofibroma in oral mucosa. One case with two painless, nodular masses, adjacent to each other in the buccal mucosa, was clinically examined with a provisional diagnosis of irritation fibroma, salivary gland tumors, neurofibroma and schwannoma. Histological examination of the smaller swelling showed features of irritation fibroma, while the features of the other mass were compatible with myofibroma or leiomyoma. Additional immunohistochemical examination established the diagnosis of myofibroma. This was a case of a myofibroma that was clinically similar to an adjacent irritation fibroma, which highlights the possibility of misdiagnosis of a myofibroblastic tumor and underlines the importance of histologic examination together with immunohistochemical and/or histochemical analysis if necessary to establish the accurate diagnosis.Medical Principles and Practice 12/2011; 21(3):288-91. DOI:10.1159/000334587 · 1.11 Impact Factor