A case of intraparotid schwannoma in a juvenile: Clinical, pathological, ultrastructural, and immunohistopathological study, including an examination of Ki-67 and MCM-3 expressions.

Pleomorphic adenoma, the most common benign nonvascular tumor of the parotid gland in juveniles, should be differentiated from other extremely rare tumors, including schwannoma. In this article, we present a rare case of an intraparotid schwannoma in a juvenile, along with the patient history, a description of pathological features, and the results of ultrastructural and immunohistochemical examination. The respective labeling indexes of Ki-67 and MCM-3, i.e., the mean proportions of positive tumor cells out of 1000 tumoral cells counted in 10 microscopic fields at ×400 magnification, given as a percentage, were found to be 0.82% and 0.4%, respectively.

Salivary duct carcinoma with rhabdoid features: report of 2 cases with immunohistochemical and ultrastructural analyses.

BACKGROUND: Salivary duct carcinoma with rhabdoid features is extremely rare. METHODS: We report 2 cases of salivary duct carcinoma with rhabdoid features treated at our institution. RESULTS: Case 1 was a 44-year-old Japanese man who had swelling in the left parotid region. This tumor consisted of residual pleomorphic adenoma and widely invasive carcinoma, which showed a diffuse growth pattern by atypical rhabdoid cells. Case 2 was a 66-year-old Japanese man who had swelling of the right cervical region. This submandibular tumor was also composed of both residual pleomorphic adenoma region and invasive adenocarcinoma components, whereas some metastatic lesions were purely composed of rhabdoid cells. Such cells were strongly and diffusely positive for cytokeratins (CKs), gross cystic disease fluid protein-15 (GCDFP), and androgen receptor (AR). Case 1 was also positive for Her-2 and p53. CONCLUSION: Both patients were diagnosed with carcinoma ex pleomorphic adenoma and their carcinomatous components were composed of salivary duct carcinoma with rhabdoid features, which is a highly aggressive tumor, similar to salivary duct carcinoma.

[Some particular aspects in cases of pleomorphic adenoma of the parotid gland]. / Unele aspecte particulare intâlnite in cazuri de adenom pleomorf al parotidei.

Twenty three cases of parotid gland pleomorphic adenoma from Surgical Oro-Maxillo Facial Clinic of "Sf. Spiridon" Hospital, Iasi, have been evaluated. In order to reveal the particular microscopic aspects, several histological techniques have been used: HE, Van Gieson, PAS, Alcian Blue and Gordon Sweet. The microscopic evidences points out the variety of microscopic forms even within the same case, and also the prevalence of some particular forms such as myo-epithelial cell predominance, squamous metaplasia and cystic degeneration. Our observations, corroborated with the one from other research, support the hypothesis of an unique ectodermal cell origin for the lesion histogenesis.

[Epithelio-myoepithelial carcinoma of the salivary glands]. / épitelial'no-mioépitelial'naia kartsinoma sliunnykh zhelez.

Epithelio-myoepithelial carcinoma was singled out as a separate nosological unit in the second revision of the International Histological Classification of Tumors of the Salivary glands (WHO, 1991). For the first time in domestic literature the article describes morphological evidence obtained at investigation of epithelial-myoepithelial carcinoma of the parotid gland using modern technologies.

Centrosomal abnormalities, multipolar mitoses, and chromosomal instability in head and neck tumours with dysfunctional telomeres.

Carcinomas of the head and neck typically exhibit complex chromosome aberrations but the underlying mutational mechanisms remain obscure. Evaluation of cell division dynamics in low-passage cell lines from three benign and five malignant head and neck tumours revealed a strong positive correlation between multipolarity of the mitotic spindle and the formation of bridges at anaphase in both benign and malignant tumours. Cells exhibiting a high rate of mitotic abnormalities also showed several chromosome termini lacking TTAGGG repeats and a high frequency of dicentric chromosomes. Multicolour karyotyping demonstrated a preferential involvement in structural rearrangements of chromosomes with deficient telomeres. The majority of malignant, mitotically unstable tumours expressed the reverse transcriptase subunit of telomerase. These data indicate that some of the genomic instability in head and neck tumours is initiated by telomere dysfunction, leading to the formation of dicentric chromosomes. These form chromosome bridges at mitosis that could prevent the normal anaphase-telophase transition. In turn, this may cause an accumulation of centrosomes and mitotic multipolarity. Telomerase expression does not confer total stability to the tumour genome but could be crucial for moderating the rate of chromosomal evolution.

Granular cell tumor of the parotid gland. A case report.

BACKGROUND: Granular cell tumor (GCT) is a relatively uncommon soft tissue tumor of putative Schwann cell origin. This tumor can occur in multiple sites as a small, nontender nodule, but the parotid gland is unusual, and only several cases have been reported. CASE: A 46-year-old woman presented with a slowly growing mass in the left preauricular region for three years. Imaging studies confirmed a nodular lesion in the superficial lobe of the left parotid gland. Fine needle aspiration (FNA) cytology revealed scattered cellular clusters and single cells with abundant granular cytoplasm and indistinct cell borders. Background exhibited eosinophilic, granular, cytoplasmic material, and some scattered naked nuclei were also noted. Histologic examination with supportive immunohistochemical and ultrastructural studies confirmed GCT. CONCLUSION: GCT of the parotid gland is very unusual. Recognition of this tumor is important to make a definitive diagnosis before an operation. FNA is useful procedure in GCT of parotid gland for a preoperative diagnosis and proper treatment.

Sclerosing polycystic adenosis of parotid gland with dysplasia and ductal carcinoma in situ. Report of three cases with immunohistochemical and ultrastructural examination.

We describe three cases of sclerosing polycystic adenosis (SPA) of the parotid gland, a salivary condition analogous to fibrocystic disease of the breast. For the first time, immunoreactivity for oestrogen and progesterone receptors was demonstrated, suggesting a possible participation of hormone stimulation in its pathogenesis. In addition, all our cases showed foci of dysplasia of the ductal epithelium, which in one case was severe enough to amount to carcinoma in situ. This feature that has not previously been reported in SPA.

Merkel cell carcinoma of the parotid gland associated with Warthin tumour: report of two cases.

AIMS: Two cases of Merkel cell carcinoma occurring simultaneously and in close association with a Warthin tumour of the parotid gland are reported. METHODS AND RESULTS: The patients were a 65-year-old man and a 70-year-old man, respectively. The Merkel cell carcinoma component was immunoreactive for chromogranin and keratin 20 and contained neuroendocrine-type granules at the ultrastructural level. CONCLUSIONS: The histogenesis of this heretofore undescribed combination is discussed.

Fine-needle aspiration biopsy of alveolar rhabdomyosarcoma of the parotid: a case report and review of the literature.

The cytologic features of an alveolar rhabdomyosarcoma arising within the parotid gland are described. The occurrence of this neoplasm as a primary malignancy in the parotid gland is very rare, and the tumor is usually not included in the cytologic differential diagnosis of parotid tumors. The diagnosis of the current case was achieved by a combination of fine-needle aspiration biopsy and frozen sections. Realizing the difficulty of recognizing this tumor both histologically and cytologically, we present this case to increase the awareness of this tumor's occurrence within the parotid gland and other salivary glands, and to highlight cytomorphologic features that will aid the pathologist in making the correct diagnosis.

Epithelial-myoepithelial carcinoma of the parotid. A case of ductal-predominant presentation with cytologic, histologic and ultrastructural correlations.

BACKGROUND: The cytologic features of the usual type of epithelial-myoepithelial carcinoma (EMC) of the parotid, with myoepithelial cell predominance, is well described in the cytology literature. In contrast, the cytologic features of ductal-predominant-type EMC has not yet been reported. CASE: An 82-year-old male presented with a 2.7-cm parotid mass of two years' duration. Fine needle aspiration smears stained with Diff-Quik showed cohesive tissue fragments outlined by metachromatic fibrils scattered in abundant, smooth, bluish background material. Ultrafast Papanicolaou stain revealed sharply outlined, large ductal cells with smooth, round to oval nuclei, prominent nucleoli and abundant vacuolated cytoplasm; the cells were arranged tridimensionally in occasional follicles that contained thick secretions. Neoplastic myoepithelial cells were occasionally seen at the periphery of tissue fragments, most commonly hidden underneath the neoplastic ductal epithelium at a slightly different focal plane; the cells had small, oval, dark nuclei and inconspicuous cell borders. The nuclear area and cell size of the neoplastic ductal cells was two and three times, respectively, that of neoplastic myoepithelial cells. CONCLUSION: EMC, depending on the ratio of ductal to myoepithelial cell components, has different cytologic presentations. This case illustrates the ductal-predominant presentation of EMC.

Mucoepidermoid carcinoma arising in Warthin's tumour of the parotid gland: report of two cases with histopathological, ultrastructural and immunohistochemical studies.

AIMS: Malignant transformation of Warthin's tumour (WT) is a rare event. We present two cases of mucoepidermoid carcinoma (MEC) arising in WT in the parotid gland. METHODS AND RESULTS: Two cases of MEC arising in WT, which were found in 185 cases of WT of the parotid gland, were investigated by light and electron microscopy, and immunohistochemistry. Both cases had largely similar macroscopic and histological features with some differences. Histologically, the tumours consisted mainly of WT with multilayered hyperplastic arrangements of oncocytic cells and focal squamous and goblet cell metaplasia. In the same tumour mass, however, the features of MEC were observed with invasion to adjacent adipose tissue. A transitional zone between WT and MEC was evident. Both patients were alive and well without evidence of recurrence 30 and 34 months after surgery, respectively. Electron microscopy revealed that cyst lining epithelial cells in WTs had abundant mitochondria whereas some of the MEC cells contained numerous tonofilaments and mucinous granules. Immunohistochemically, oncocytic cells of WTs were strongly positive for mitochondria and SalylTn was extensively stained in MECs. The labelling index for Ki67 was obviously higher in the carcinoma cells than the epithelial cells of WT. CONCLUSIONS: Our cases confirmed the possibility of malignant transformation of the epithelial component in WT to MEC.

[Giant acinic cell parotid gland adenocarcinoma of the papillary- cystic type]. / Adenocarcinoma gigante de células acinares de tipo quístico papilar en parótida.

A case of a 38-year-old male having an acinic cell adenocarcinoma of the parotid gland is reported. The tumor measured 22 cm and histologically it was of the papillary-cystic type. The following features were of interest: 1) the tumor size surpassed the size of previous reported acinic cell adenocarcinomas by 9 cm; and 2) the rarity of its histological variety (cystic papillary) demanded immunohistochemical and electron microscopic studies to confirm the diagnosis.