Apostolos Epivatianos

Pyogenic granuloma of the oral cavity: Comparative study of its clinicopathological and immunohistochemical features

There are two histological types of pyogenic granuloma (PG) of the oral cavity: the lobular capillary hemangioma (LCH) and non‐LCH type. The aim of the present study was to examine and compare the clinical features, etiological factors, diameter of vascular elements and immunohistochemical features of LCH and non‐LCH histological types of PG to determine whether they are two distinct entities. Thirty cases of LCH and 26 cases of non‐LCH PG were retrieved and retrospectively studied. Clinically, LCH PG occurred more frequently (66.4%) as sessile lesion whereas non‐LCH PG occurred as pedunculated (77%). Non‐LCH PG was associated more frequently (86.4%) with etiological factors. The lobular area of the LCH PG contained a greater number of blood vessels with small luminal diameter than did the central area of non‐LCH PG. In the central area of non‐LCH PG a significantly greater number of vessels with perivascular mesenchymal cells non‐reactive for α‐smooth muscle actin and muscle‐specific actin was present than in the lobular area of LCH PG. The differences found in the present study suggest that the two histological types of PG represent distinct entities.

Black hairy tongue in a 2‐month‐old infant

Abstract:  Black hairy tongue (BHT) is an unusual condition in adults, and is characterised by marked accumulation of keratin on the filiform papillae of the dorsum of the tongue resulting in a hairlike appearance. The colour of the papillae may vary from brown to black. We describe a case of BHT in a 2‐month‐old infant. An extended review of the literature suggests that our case is the youngest ever reported. In conclusion, although BHT is considered benign, clinical, haematological and histological, evaluation is recommended to exclude several entities which can present as pigmented lesions of the oral mucosa.

Minor salivary glands of the lips: a novel, easily accessible source of potential stem/progenitor cells

ObjectivesCells with stem/progenitor properties have been detected in major salivary glands, but no data are available on their presence within minor salivary glands (MSGs). This study aimed to isolate and characterize potential stem/progenitor cells from human MSGs.Materials and methodsMSGs of the lower lip were surgically obtained during biopsy for Sjogren’s syndrome investigation that finally proved to be histologically normal. The established MSG cultures were assessed for morphology, proliferation, colony-forming-unit efficiency, multipotentiality, and immunophenotypic characteristics.ResultsA mixed population of fibroblast-like and a few flat-shaped epithelial-like cells was obtained. These cells were capable for osteogenic, adipogenic, and neurogenic differentiation. Evidence for strong stem cell potency was observed by the detection of early stem cell markers, like Nanog, Oct-3/4, and SSEA-3. These cells also expressed characteristic mesenchymal stem cell markers, including CD90-Thy1, CD105, CD49f, CD81, nestin, CD146, and Stro-1, but were negative for CD117/C-KIT, CD45, and CD271/NFG. In addition, positivity for keratins 7/8 in part of the population was indicative of an epithelial phenotype, whereas these cells were negative for aquaporin-1 expressed in acinar/myoepithelial cells during development.ConclusionsBased on these data, a cell population with stem/progenitor characteristics was primarily isolated from labial MSGs. The morphologic and immunophenotypic features indicated that this population is mixed with mesenchymal (mainly) and epithelial characteristics.Clinical relevanceDue to their large number and superficial distribution in labial mucosa, MSGs may be proposed as a potential easily accessible source of adult stem/progenitor cells for regenerative therapies of glandular organs with parenchymal pathology.

Immunohistochemical detection of E-cadherin in certain types of salivary gland tumours

OBJECTIVES To investigate the topography of E-cadherin and its possible correlation with the histological phenotype of salivary gland tumours. MATERIAL AND METHODS Archival formalin-fixed, paraffin-embedded sections of 54 benign and 56 malignant tumours and 24 samples of normal and inflamed salivary gland tissue were studied immunohistochemically using an Envision/horseraddish peroxidase (HRP) technique. RESULTS In normal and inflamed salivary gland samples, E-cadherin was expressed at the membrane of acinar, myoepithelial and ductal cells located at cell-cell contact points. Reduction and/or absence of E-cadherin was only observed in pleomorphic adenoma at the peripheral cells of the duct-like or island structures, or in the cells exhibiting plasmacytoid or stromal differentiation. Neoplastic epithelium in Warthins tumours and in myoepithelial and oncocytic adenomas was strongly positive. Furthermore, a weak to moderate loss of expression which was related to tissue tumour subtype was seen in malignant tumours such as: adenoid cystic carcinomas; polymorphous low-grade adenocarcinomas; acinic cell carcinomas; and mucoepidermoid low-grade, epithelial-myoepithelial, lymphoepithelial and squamous low-grade carcinomas. Moderate to extreme loss or alternative cytoplasmic non-functional expression were observed in cases of salivary ductal carcinoma, carcinosarcoma, myoepithelial carcinoma, oncocytic adenocarcinoma, unspecified adenocarcinoma and squamous high-grade carcinomas. CONCLUSION This study suggests a direct association of E-cadherin expression with neoplastic histologic phenotype, which is lost in the more undifferentiated and invasive epithelial salivary gland tumours.

Immunohistochemical study of fibroblasts and mast cells in chronic submandibular sialadenitis

AIM To further our understanding of the processes involved in fibrosis that occurs in chronic submandibular sialadenitis by investigating the distribution of myofibroblasts, CD34-positive fibroblasts and tryptase-containing mast cells. MATERIALS AND METHODS Thirty specimens of chronic submandibular sialadenitis with varying degrees of fibrosis and five normal submandibular glands were examined immunohistochemically for the presence of CD34, alpha-smooth-muscle-actin, desmin and tryptase. RESULTS Myofibroblasts were not demonstrated by the techniques for alpha-smooth-muscle-actin or desmin. CD34-positive fibroblasts were found around normal and moderately atrophic acini, but were not found around extremely atrophic acini and duct-like structures or in periductal and interlobular fibrous tissue. Tryptase-containing mast cells were found around vessels in normal submandibular glands. They were found in increased numbers in chronic submandibular sialadenitis, particularly in glands with widespread fibrosis, in which they were found in the fibrous tissue, and in which the increase was statistically significant. CONCLUSIONS The results of this investigation suggest that tryptase-containing mast cells are likely to be involved in the fibrosis of chronic submandibular sialadenitis, but myofibroblasts and CD34-positive fibroblasts are not.

Localized Tongue Amyloidosis in a Patient with Neurofibromatosis Type II

BackgroundLocalized Amyloidosis (AL) may rarely involve oral mucosa. This is the first known reported case describing the development of tongue AL in a 30-year-old patient with Neurofibromatosis (NF) type-2.CaseA female patient presented with a painless, well-circumscribed nodule of the tongue. Her medical history included NF type-2 with chromosome-22 abnormal karyotype (mosaicism), multiple intracranial and spinal meningiomas/schwannomas and unilateral blindness/deafness. The biopsy of the excised lesion of the tongue revealed subepithelial accumulation of an amorphous, nodular, fibrillar material positive for Congo red. Blood examination showed increased Thyroxine-T4 due to thyroid multinodular colloid goiter, but excluded any other hematological/immunological disorder or organ dysfunction. No recurrence was observed after a six-month follow-up.ConclusionThis case highlights the possibility of oral manifestations as the only sign of AL and reveals the unexpected co-existence of AL and NF 2, for the first time.

Coexistence of Mucous Retention Cyst and Basal Cell Adenoma Arising from the Lining Epithelium of the Cyst

Objective: To report 2 cases of coexisting mucous retention cyst and basal cell adenoma arising from the lining epithelium of the cyst. Clinical Presentation and Intervention: Two cases of painless swellings, well-demarcated, soft to palpation, and located in the submucosa of the upper lip were clinically examined with the provisional diagnosis of mucocele or salivary gland tumor. Histological examination showed the presence of a large unilocular cystic cavity in many parts surrounded by single or bilayered lining epithelium composed of flattened to cuboidal cells, and in other parts surrounded by projections of cells arranged in a trabecular pattern far into the cystic cavity. The trabeculae were composed of basal and low columnar cells that sometimes formed small duct-like structures. Immunohistochemistry showed that the lining epithelium of the cystic cavity and the cells of the projections expressed cytokeratin 7 and high-molecular-weight cytokeratins. The cells of the projections were weakly positive for S-100 protein and negative for vimentin and α-smooth muscle actin. Based on the results, a diagnosis of coexisting mucous retention cysts and basal cell adenomas arising from the lining epithelium of cysts was made. Conclusion: The coexistence of mucous retention cysts and basal cell adenomas arising from the lining epithelium of the cyst is reported.

Infiltrating Angiolipoma of a the Oral Cavity: Report of a Case and Literature Review

enign lipomatous tumors are classified into 5 groups: ) lipoma; 2) variants of lipoma; 3) heterotopic lipoas, hamartomatous lesions; 4) infiltrating or difuse neoplastic or non-neoplastic proliferations of ature fat; and 5) hibernoma. Angiolipoma is a ariant of lipoma and is distinguished in the noninltrating and infiltrating type. Infiltrating angiolioma most often occurs in the trunk and extremiies and is rare in the head and neck region. Some uthors believe that infiltrating angiolipoma ould represent diffuse angiomatosis associated ith fat, rather than a neoplasm. Review of the iterature revealed only 8 cases of infiltrating angio-

Myofibroma of the oral mucosa: a case report.

Objective: To report a case of coexisting irritation fibroma and myofibroma in oral mucosa. Clinical Presentation and Intervention: 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. Conclusion: 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.

Myofibroblasts and Transforming Growth Factor-Beta1 in Reactive Gingival Overgrowths

ABSTRACT Objectives The purpose of this study was to evaluate the oral health-related quality of life of patients treated with implant-supported mandibular overdentures and to compare the attachment systems used. Material and Methods The presence of myofibroblasts as well as transforming growth factor-beta1 was examined in twenty cases of fibrous epulis and 22 ossifying fibrous epulis, using immunohistochemistry. Results Myofibroblasts positive for alpha smooth muscle actin and vimentin but negative to desmin were found in 20% and 45% in fibrous epulis and ossifying fibrous epulis, respectively. Myofibroblasts were distributed in areas with and without inflammatory infiltration and their presence in inflammatory areas was not related with the degree of inflammatory infiltration. A percentage of 21 - 60% of fibroblasts and chronic inflammatory cells expressed transforming growth factor-beta1 in all cases. Conclusions These data suggest that transforming growth factor-beta1 and myofibroblasts contribute to the formation of collagenous connective tissue in fibrous epulis and ossifying fibrous epulis. Myofibroblasts are mainly presented in ossifying fibrous epulis than in fibrous epulis. It seems to be no relationship between the presence of myofibroblasts and the degree of inflammatory infiltration of the lesions.