Ghost cells in pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor: histological, immunohistochemical, and ultrastructural study.

BACKGROUND: Pilomatrixoma, craniopharyngioma, and calcifying cystic odontogenic tumor are the main entities presenting ghost cells as an important histological feature, in spite their quite different clinical presentation; it seems that they share a common pathway in the formation of these cells. The aim of this study is to examine and compare the characteristics of ghost and other cells that form these lesions. METHODS: Forty-three cases including 21 pilomatrixomas, 14 craniopharyngiomas, and eight calcifying cystic odontogenic tumors were evaluated by immunohistochemistry for cytokeratins, CD138, ß-catenin, D2-40, Glut-1, FAS, CD10 and also by scanning electron microscopy. RESULTS: The CKs, CD138, ß-catenin, Glut-1, FAS, and CD10 were more often expressed by transitional cells of craniopharyngioma and calcifying cystic odontogenic tumor, compared with pilomatrixoma. Basaloid cells of pilomatrixoma showed strong positivity for CD138 and CD10. Differences on expression pattern were identified in transitional and basal cells, as ghost cells were negative for most antibodies used, except by low expression for cytokeratins. By scanning electron microscopy, the morphology of ghost cells were similar in their fibrillar cytoplasm, but their pattern varied from sheets in pilomatrixoma to small clusters in craniopharyngioma and calcifying cystic odontogenic tumor. CONCLUSIONS: Mechanisms involved in formation of ghost cells are unknown, but probably they follow different pathways as protein expression in the basal/transitional cells was not uniform in the three tumors studied.

Polyomavirus-induced pilomatricomas in mice: from viral inoculation to tumour development.

Polyomavirus has been used extensively to study tumour induction in mice. Although most neoplasms are well characterized, those arising from hair follicles have been referred to by different names during the last four decades. The purpose of this research was to contribute to a more accurate histological characterization of these tumours as well as to study the viral progression from the onset of infection to the development of neoplasms. Polyomavirus A2 was inoculated into newborn C3H/BiDa mice, and at different time-points (from 5 to 70 days post-inoculation) the mice were sacrificed and studied using histological, immunocytochemical, ultrastructural and virological methods. The fully developed hair follicle tumours consisted of a proliferation of matrix cells that evolved into 'shadow' cells with empty nuclei and finally into amorphous keratin; the tumours were therefore diagnosed as pilomatricomas. Viral VP-1 was observed only in fully differentiated cells and not in proliferating-cell-nuclear-antigen (PCNA)-positive cells in the same tumour. In conclusion, Polyomavirus first replicated in the skin, and then disseminated through the blood and reached the outer sheath of the hair follicles and finally infected matrix cells, leading to the development of pilomatricomas from which infectious virus was isolated.

Pilomatrixoma cervical osificante / Ossifying cervical pilomatrixoma

El Pilomatrixoma o Tumor epitelial calcificante de Malherbe es un tumor dérmico o subcutáneo, que afecta mayormente a la población pediátrica, originado en la raíz pilosa o zonas adyacentes, generalmente benigno y de lento crecimiento. De ellos, menos de una tercera parte se osifican.La oportunidad de haber asistido en nuestro Servicio consecutivamente dos casos, en edad infantil, y de localización Cervical en Región Espinal, el primero de ellos osificado, nos plantea la descripción de los mismos y la revisión del tema (AU)

Detection of apoptosis by in situ labeling in pilomatricoma.

Pilomatricoma is a benign epidermal appendage tumor with differentiation toward hair cortex cells. It is composed of varying percentages of basophilic cells, shadow cells, and transitional cells. Transitional cells seem to be apoptotic cells as evidenced by their morphological and ultrastructural characteristics. We investigated apoptosis in ten specimens of pilomatricoma by the transferase-mediated dUTP-biotin nick end labeling (TUNEL) technique. TUNEL-positive structures were detected in both transitional cell and amorphous debris zones, but not in either basophilic cell or shadow cell zones. In the transitional cell zone, apoptotic cells were found either in groups or bands, while in the amorphous debris zone, apoptotic bodies of varying sizes were seen diffusely. These findings indicate that transitional cells, due to the fact that they are dying cells, may not differentiate into the shadow cells. This view is supported by the facts that the transition of basophilic cells into the shadow cells is abrupt in some areas and that tumor cells, with or without ultrastructural characteristics of apoptosis, are found in the transitional cell zone. Furthermore, ultrastructural nuclear changes in shadow cells are different from those seen in apoptosis. Therefore, we propose that the name of transitional cells should be changed to "condensed cells." Although it has been conventionally though that basophilic cells in pilomatricoma differentiate directly and/or via transitional cells into shadow cells, we demonstrate that basophilic cells undergo two different processes. The first is differentiation directly into shadow cells, an the second is passage, via "condensed cells" (transitional cells), into the amorphous debris that results from tumor kinetics.

[Pilomatrixoma of the auricle. Differential diagnosis with carcinoma pilomatrixoma]. / Pilomatrixoma de pabellón auricular. Diagnóstico diferencial con el carcinoma pilomatrixial.

A 34 year-old man, with a two centimeter diameter quickly growing nodule on the auricular pavillion is presented. After mass excision the histologic diagnosis of pilomatrixoma was made. Pilomatrixoma is a rare benign tumor arising on the hair matrix. The differential diagnosis include pilomatrix carcinoma, a locally and recurrent aggressive tumor capable to make pulmonary metastasis. A review of the literature is included, with emphasis on the clinical and histopathological aspects and the therapeutic attitude.

[Malherbe's calcifying epithelioma (pilomatrixoma) of the cervical middle line. A case report]. / Epitelioma calcificante de malherbe (pilomatrixoma) en línea media cervical. Presentación de un caso.

Calcifying epithelioma of Malherbe (Pilomatrixoma) is a rare benign tumor, starting in the hair matrix and clinically resembling a hard subcutaneous swelling. The most common sites of localization are the head and neck regions. Women show a sizeable incidence. We report a case located in the prelaryngeal area and emphasize cytodiagnostic by fine needle aspiration. The correct treatment consists in pure and simply surgical excision under local anesthesia.