Dermatoscopy of an invasive melanoma on the upper lip shows possible association with Laugier-Hunziker syndrome.

We report mucosal melanoma of the upper lip in a patient affected by the Laugier-Hunziker disease. Using dermatoscopy, two distinct parts were identified in the same mucosal area: nodular (malignant) and macular (benign). A complete surgical excision was performed and the patient has been free of disease for 16 months.

Morphometric study of desmosomes from oral squamous cell carcinoma.

The authors studied ultrastructural characteristics of desmosomes from oral squamous cell carcinoma, reporting the cellular differentiation and size of the desmosomes. The length of the desmosome profiles was measured with a Zeiss KS-300. The desmosomes were grouped according to their size and the tumor histological grading. Statistical analysis indicated a significant correlation (p < .001) between the size of the desmosomes and the histological grading group of the malignancy. The comparison of the desmosome size among the tumor histological grading groups also showed significant difference (p < .001). A multiple comparisons test indicated homogeneity in the size of desmosomes within the histological grading groups: 100% in the well differentiated, 95.2% in the moderately differentiated, and 50% in the poorly differentiated group. The preliminary data strongly suggest that the homogeneity of length of the desmosome profiles may be exploited for diagnostic strategies.

De novo desmoplastic neurotropic melanoma of the lower lip: a neoplasm with ominous behavior.

Desmoplastic neurotropic melanoma represents a rare histologic variant of malignant melanoma that is characterized by a proliferation of spindle cells in a densely collagenous stroma with pronounced neurotropism. A 60-year-old man appeared for evaluation of a mass in the lower lip. The labial mucosa was intact, and the lesion had been present for 2 months. The tumor was surgically removed, and after immunohistochemical and ultrastructural analysis it was diagnosed as desmoplastic neurotropic melanoma. The tumor recurred 6 months later, with involvement of the inferior alveolar nerve.

Ultraestrutura da parede da fístula congênita de lábio inferior na Síndrome de Van Der Woude / Ultrastructure of the wall of congenital fistula of the lower lip in the Van Der Woude Syndrome

A parede mucosa de fístulas congênitas de lábio inferior de 4 pacientes do Hospital de Pesquisa e Reabilitaçäo de Lesöes Lábio-Palatais de Bauru-SP, foram analisadas ao microscópio eletrônico de transmissäo. A fístula de um dos pacientes, em sua porçäo proximal apresentou revestida por epitélio pavimentoso estratificado paraqueratinizado, nas porçöes média e do fundo, o epitélio foi sempre do tipo näo queratinizado. Nos demais pacientes, a parede das fístulas em toda sua profundidade estava constituída por epitélio näo queratinizado. As características ultraestruturais, de ambos os tipos de epitélio näo foram semelhantes às descritas na literatura, para a mucosa humana paraqueratinizada e näo queratinizada. A lâmina própria em todos os casos estava formada por tecido conjuntivo denso näo modelado constituído de densa rede de fibras colágenas

[Mast cells in the labial cancer: histochemical and electron microscopical study].

The labial cancer tissue of 24 cases and normal labial tissue of 7 cases were studied histochemically and electron microscopically. The result showed that the number of mast cells around the periphery of labial cancer tissue increased significantly. The histochemical properties of these mast cells differed from those in the normal labial tissue. The former did not contain heparin which was present normally. Under electron microscope, according to the characteristic ultrastructure, the mast cells around the labial cancer were TC mast cells. Some of them showed the appearance of degranulation, and contacted intimately with cancer cells, lymphocytes and macrophages, etc. These findings suggest that together with lymphocytes, macrophages, these mast cells contribute to the defence reaction to the cancer tissue.

Apocrine carcinoma of the lip: a case report including immunohistochemical and ultrastructural study, discussion of differential diagnosis, and review of the literature.

The light microscopic, immunohistochemical, and ultrastructural features of a case of apocrine carcinoma of the upper lip of a 54-year-old white man are described. The neoplasm had a cribriform intraductal component resembling apocrine carcinoma of the breast. The tumor had irregular borders and infiltrated skeletal muscle. The neoplastic cells had abundant eosinophilic granular cytoplasm and showed apical decapitation secretion characteristic of apocrine differentiation. The differential diagnosis is discussed with particular reference to distinction of the tumor from oncocytic carcinoma and ductal carcinoma of minor salivary gland.

Canalicular adenoma: report of five cases with ultrastructural observations.

Canalicular adenomas from five patients were examined by light and electron microscopy. All patients were over 50 years of age; 4 of the lesions were from the upper lip, 4 were cystic, 2 showed capsular invasion and 1 was multifocal. Histopathologically there were epithelial duct-like or canalicular structures cut at various angles and epithelial islands surrounded by hyalinized and mucinous connective tissue that contained little collagen. Ultrastructurally the epithelial islands contained many small lumina and connective tissue islands. The characteristic epithelial cell was columnar or cuboidal, extended from the lumina to the connective tissue, had almost straight lateral cell boundaries with desmosomes that predominated near the lumina, and possessed gap junctions and a small number of tight junctions. Their main cytoplasmic constituents were ribosomes, mitochondria, rough-surfaced endoplasmic reticulum and microfilaments. These findings show that canalicular adenomas are truly monomorphic and support the concept that they are derived from the cells of excretory ducts.

[Neurofibroma of the lower lip]. / Neurofibroma de labio inferior.

Reporting a nervous tumor diagnosed as Neurofibroma, which owing to its localisation, on the lower lip, and its possible origin, from a salivary gland, should be considered an extraordinary rarity. The AA, make a bibliographic review of the commonest sites of the growth, the histological description and consider some possible differential diagnosis with special emphasis to the schwannoma and the Recklinghausen's disease.

Merkel cell carcinoma of the labial mucosa. An immunohistochemical and ultrastructural study with a review of the literature on oral Merkel cell carcinomas.

Merkel cell carcinoma is a rare cutaneous neuroendocrine tumor that occurs predominantly in the head and neck region of older patients. An 88-year-old white man had an erythematous, umbilicated tumor on his lower lip, which on histopathologic examination showed solid sheets of infiltrating basaloid round cells with a high mitotic index. Globular, paranuclear immunostaining for low-molecular-weight cytokeratins (Nos. 8, 18, and 19) and neurofilament was observed. On ultrastructural examination, the tumor cells demonstrated paranuclear whorls of intermediate filament aggregates and occasional electron-dense granules. This unique cytokeratin- and neurofilament-staining pattern with coexpression enabled the Merkel cell carcinoma to be differentiated from other small cell malignant tumors that included metastatic neuroendocrine carcinomas from other regions. The follow-up 1 year after surgery and radiation showed that the patient remained disease free. Review of the literature revealed 11 cases of oral Merkel cell carcinomas with a predilection for the labial mucosa of older men. The mode of treatment and the clinical course of these cases are also presented, with an update on therapeutic management of Merkel cell carcinomas.

Alteraciones ultraestructurales en la carcinogénesis bucal / Ultrastructural alteration in oral carcinogenesis

Atendiendo a la marcada acción mutagénica y carcinogénica de los hidracarburos policíclicos aromáticos contenidos en el humo desprendido de la combustión de cigarros y tabacos se realizó el presente estudio para precisar las modificaciones estructurales producidas por la aplicación de un condensado de humo de cigarros sobre la mucosa labial de ratones machos IBFI (IOR/HabxC57/BL) a diferentes períodos. En la semana 44 se presentaron carcinomas epidermoides evidentes tanto en los grupos que recibieron CH como B(a)p. La distribución de los tonofilamentos de forma compacta hacia la periferia citoplasmática, fueron, entre otros, rasgos de interés que aparecieron en las lesiones neoplásicas estudiadas durante la semana 44

Alteraciones ultraestructurales en la carcinogénesis bucal / Ultrastructural alteration in oral carcinogenesis

Atendiendo a la marcada acción mutagénica y carcinogénica de los hidracarburos policíclicos aromáticos contenidos en el humo desprendido de la combustión de cigarros y tabacos se realizó el presente estudio para precisar las modificaciones estructurales producidas por la aplicación de un condensado de humo de cigarros sobre la mucosa labial de ratones machos IBFI (IOR/HabxC57/BL) a diferentes períodos. En la semana 44 se presentaron carcinomas epidermoides evidentes tanto en los grupos que recibieron CH como B(a)p. La distribución de los tonofilamentos de forma compacta hacia la periferia citoplasmática, fueron, entre otros, rasgos de interés que aparecieron en las lesiones neoplásicas estudiadas durante la semana 44

Microcystic adnexal carcinoma: a light microscopic, immunohistochemical and ultrastructural study.

We report a case of microcystic adnexal carcinoma (MAC) occurring on the upper lip of an 82-year-old woman. Microscopically the tumor showed both pilar and sweat gland differentiation, involved the entire dermis and subcutaneous tissue, and invaded perineural spaces. Immunoperoxidase studies revealed carcinoembryonic antigen to be present in the ductal lining cells and in the amorphous content in the lumen, confirming sweat gland differentiation. The S-100 protein was positive in dendritic cells within the solid cell nests, but negative in cells lining cystic spaces. Ultrastructural study confirmed that the neoplasm was composed of two components, with pilar and eccrine differentiation. The former showed concentric layers of squamous epithelial cells with well-developed desmosomes and cytofilaments. The latter had ductal and alveolar structures; the ultrastructural features included: i) numerous villous folds of plasma membrane to interdigitate each other by focal desmosomes, ii) aggregates of cytofilaments, and iii) basally located myoepithelial cells which were separated from the surrounding stroma by rather thick basement membrane. In addition, distinct amyloid deposition was also observed on ultrastructural examination. To our knowledge, amyloid deposition has not been previously reported in MAC.

A rare variant of acinic cell carcinoma of the upper lip: a case report and review of the literature.

Acinic cell carcinomas of the lip are most uncommon. An exhaustive search of the Japanese- and English-language literature has revealed only 17 previously reported cases. One additional occurrence, a rare variant of this type of neoplasm, with mucous differentiation, that occurred in the upper lip of a 60-year-old man is described here. A brief review of the literature on this type of lip tumor is also given.

Microcystic adnexal carcinoma. Electron microscopic and immunohistochemical study.

We present a patient with microcystic adnexal carcinoma. The lesion was an indurated plaque on the skin of the right upper lip of a 58-year-old woman which was slowly growing during 27 years. Carcinoembryonic antigen was immunoreactive in the luminal contents of the tumor ducts and in the cytoplasm of cells surrounding ducts. S-100 protein was positive in the cytoplasm of a few cells at the lower dermis. These observations suggested that this tumor was related to sweat glands. Furthermore, electron microscopy revealed that tumor cells had features of eccrine ductal cells. These observations confirm that this tumor appeared at least capable of eccrine duct differentiation.

Neuroendocrine carcinoma of the lip (Merkel cell tumour) examined by electron microscopy and immunohistochemistry.

A definite diagnosis of neuroendocrine carcinoma of the skin is seldom made on initial histological examination; the tumour is usually reported as a poorly differentiated or anaplastic carcinoma. By applying electron microscopy and immunohistochemistry, a correct diagnosis can be made. The ultrastructural examination shows dense-core membrane-bound granules, intermediate perinuclear filaments and desmosome-like junctions. Immunohistochemistry reveals positive staining for neuron-specific enolase and keratin, the latter in a characteristic paranuclear distribution. Confronted with an unusual clinical picture or indefinite histological diagnosis, tissue specimens should be secured for the above mentioned ancillary procedures.

Anchoring fibrils in a spindle cell squamous carcinoma.

To the best of our knowledge anchoring fibrils in tumours have been reported to occur only in cutaneous cylindromas and squamous cell carcinomas of oral mucosa and larynx. In this paper we describe a difficult-to-diagnose malignant spindle cell tumour where the striking feature was the presence of large numbers of anchoring plaques and anchoring fibrils in the tumour matrix. On the basis of light microscopic and immunohistochemical studies several diagnoses were preferred, such as malignant fibrous histiocytoma, neurofibrosarcoma, malignant schwannoma, desmoplastic melanoma and spindle cell squamous carcinoma (more fully referred to as 'spindle cell variant of squamous cell carcinoma'). The presence of anchoring fibrils in this tumour strongly supports the diagnosis of spindle cell squamous carcinoma. Our knowledge about the occurrence of anchoring fibrils in tumours is scant, perhaps because they are likely to be missed unless they are present in large numbers, or perhaps because they are mistaken for native collagen fibrils. It seems to us that a systematic search for anchoring fibrils in tumours is warranted, for knowledge about their occurrence or absence in various types of tumours may add yet another diagnostic marker in the armamentarium of the diagnostic electron microscopist and it may also assist in resolving the histogenesis of some controversial neoplasms.

Congenital hemangiopericytoma: report of a case.

A congenital hemangiopericytoma of the lower lip, first detected by prenatal ultrasound, was only partially resected and involuted over the next 20 months.

A transmission electron microscopic study of two cases of oral smooth muscle neoplasm.

Two cases of smooth muscle tumors that had appeared in the oral regions were examined by means of histopathology and electron microscopy. One was a case of angiomyoma that appeared in the lip of a 33-year-old man, and the other was a case of leiomyosarcoma in the maxilla of a 63-year-old woman. The results of the examination of both cases were as follows: the benign tumor (angiomyoma) was composed of mainly mature smooth muscle cells having dark cytoplasm, and the malignant tumor (leiomyosarcoma) consisted mainly of two types of cells, undifferentiated mesenchymal cells or fibroblast-like cells (type I) and myofibroblast-like cells (type II). Based upon these results, the relationship between the myogenous differentiation and the component cell types, and biological behavior of these smooth muscle tumors was discussed.

[Neurothecoma of the skin]. / Neirotekoma kozhi.

A rare benign skin tumor of the lower lip in a male of 22 is described. On the basis of the analysis of differential-diagnostic features using histological, immunohistochemical and electron-microscopic methods, the tumor is verified as a neurothecoma histologically connected with nerve sheath elements.