[An atypical rhabdoid/teratoid tumor. A presentation of three cases and review of the literature]. / Tumor rabdoide/teratoide atípico. Presentación de tres casos y revisión de la literatura.

INTRODUCTION: The atypical rhabdoid/teratoid tumor of the central nervous system (CNS) has emerged from a variant of medulloblastoma to become a distinctive clinico-pathological condition over the past ten years. This is more than simply nosological importance, since the five year survival expected in medulloblastomas is considerably better than the 11 months (average) seen in rhabdoid/teratoid tumors. OBJECTIVE: To describe the main clinico-pathological characteristics of a recently recognized condition, emphasizing its polymorphism and differential diagnosis. PATIENTS AND METHODS: We report the clinical, radiological, cytohistopathological and immunohistopathological aspects of three atypical rhabdoid/teratoid tumors diagnosed in the Hospital A.B.C. of Mexico City. RESULTS: The three tumors were seen in boys aged 18 months, 5 years and 14 years, localized to the right cerebellum, left cerebral hemisphere and left cerebellum, respectively. Different markers were shown including: vimentin, cytokeratin, epithelial membrane antigen, gliofibrillare acid protein, synaptophysin, alpha fetoprotein, S100, (HHF-35) actin, cromogranin, neurofilaments, human chorionic gonadotrophin, placental alkaline phosphatase, desmin, CD99 and carcinoembryonary antigen. We established the morphological similarities and differences in our cases, and noted the profuse vascular proliferation which in one case resembled vascular neoplasia. We compared our results with other published cases. CONCLUSIONS: The atypical rhabdoid/teratoid tumor of the CNS may easily be confused with other primary or metastatic tumors since the rhabdoid characteristics do not only occur in this tumor. Also the rhabdoid aspect may be less marked and in some cases does not predominate. Some zones of the tumor may be identical to other embryonic tumors of the CNS and the immunophenotype be superimposed on that of other neoplasias of the nervous system.

Salivary gland tumors of the mandible.

Primary central salivary gland carcinomas of the mandible are uncommon neoplasms. Consequently, their proper diagnosis is often in doubt. We retrospectively studied the cases of 16 patients treated at The University of Texas M. D. Anderson Cancer Center and the Institut Gustave Roussy from 1950 to 1990. Patients ranged in age from 24 to 76 years (mean, 51 years). Nine patients were women and seven were men. Each case involved either the angle or the posterior body of the mandible. Swelling, pain, and trismus were the most frequent complaints. For all patients, radiography revealed a cystic defect resembling an osteolytic odontogenic lesion or metastasis. Five histologic types of carcinoma were diagnosed: seven cases of mucoepidermoid carcinoma (five low-grade and two high-grade), four cases of adenoid cystic carcinoma, two cases of adenocarcinoma, two cases of acinic-cell carcinoma, and one case of epithelial-myoepithelial carcinoma. All patients were treated with wide surgical excision. Eight patients received postoperative irradiation. Five patients with low-grade mucoepidermoid carcinoma, two with acinic-cell carcinoma, and one with epithelial-myoepithelial carcinoma were free of disease 2 to 15 years after initial treatment (mean, 6.2 years). Two patients with adenoid cystic carcinoma are living with lung metastasis. The remaining six patients died of their carcinomas within 4 years after initial treatment. Because of their unique morphology and clinical behavior, these tumors should be distinguished from other intraosseous neoplasms of the mandible, including those with clear-cell patterns.

[Atypical regenerative changes, dysplasia, and carcinoma in situ in chronic gastritis associated with Helicobacter pylori]. / Cambios regenerativos atípicos, displasia y carcinoma in situ en gastritis crónica asociada con Helicobacter pylori.

In the present work we study the association between chronic active gastritis (CAG), atypical regeneration and dysplasia and gastric Helicobacter pylori (HP) infection. We study two groups of endoscopic biopsies. Regenerative changes and dysplasia were evaluated according to Gandur-Maymneh et al. classification which was simplified in typical and atypical regeneration, and mild and severe dysplasia. The group I included 94 patients with CAG, 9 with chronic non active gastritis (CNAG) and 2 with normal gastric mucosa. CAG was graded according to activity in; severe 28 patients; moderate 54 patients and; mild 12 patients. HP association in these cases was 100%, 77% and 25%. In cases of CNAG HP was present in 22%, there were not HP in normal gastric mucosa. There were atypical regeneration in 25% of moderate CAG and in 42% of severe CAG. Mild dysplasia was present in 7.5 and 25% in cases of moderate and severe CAG. Two biopsies showed severe dysplasia. In addition, intestinal metaplasia was found in 15% of CAG, the metaplasia was present in 25% of cases with CAG and atypical regeneration; in 54% of cases with mild dysplasia and; in 100% on cases with severe dysplasia. The group II included 9 cases of gastric cancer of intestinal type, 7 cases of diffuse type, and 4 cases of mixed type. In all these cases there was viewed CAG associated to HP infection in non-neoplastic mucosa. In 75% of cases there were showed atypical regeneration and 60% presented some type of dysplasia. There was transition between atypical regeneration and dysplasia in 6 cases of intestinal gastric cancer and in 3 cases of mixed type. We found relationship between the intensity of CAG and HP colonization, and the association with atypical regeneration and dysplasia.

Plasmacytoid myoepithelioma of the laryngeal region: a case report.

The first case of plasmacytoid myoepithelioma of the laryngeal region is presented. The tumor showed immunoreactivity for the S-100 protein, low molecular weight cytokeratin, and vimentin. Staining was negative with muscular actin and glial fibrillar acid protein. By electron microscopy the tumor cells showed abundant microfibrillar material, elongated densities resembling smooth muscle dense bodies, pinocytic vesicles, and replicated basal lamina. The myoepithelial nature of plasmacytoid tumors of the salivary gland has been questioned.

Hypopharyngeal sebaceous carcinoma: a case report.

A hypopharyngeal squamous-cell carcinoma with sebaceous differentiation is reported. In the primary as well as the metastatic lymph nodes, the tumor showed basaloid, squamous, and sebaceous cells. In addition, immunostaining for S-100 protein and vimentin manifested scattered cells showing cytoplasmic processes suggesting myoepithelial cells. An exhaustive review of the literature revealed only one similar case previously reported. The probable origin from the minor salivary glands is discussed.

Primary prostatic Wilms' tumor.

The first case of primary Wilms' tumor of the prostatic gland is described. It occurred in a 32-year-old man. Histologically, it consisted of a triphasic tumor; tubular and glomeruloid structures were identified, among prominent blastematous sheets and in an edematous stroma. No teratomatous components were encountered. We propose that this prostatic primary, nonteratomatous Wilms' tumor can arise from persistent, nephrogenic, blastematous rests in the prostate, in relation to the Wolffian duct system.

Paragangliomas of the head and neck. Immunohistochemical analysis of 16 cases in comparison with neuro-endocrine carcinomas.

Sixteen cases of paragangliomas of the head and neck including 8 of the vagal body, 3 of the carotid body, 2 jugulotympanic, 2 vagal or jugulotympanic and 1 of the larynx were analysed. Clinically, 13 tumors were benign, 2 showed local aggressivity and 1 showed metastases. All tumors were tested with antisera directed against neuron-specific enolase (NSE), chromogranin A (CGA), S-100 protein, neurofilaments (NF), glial fibrillary acid protein (GFAP) and cytokeratin (CK). Immunohistochemical results were compared with those of 5 cases of neuroendocrine carcinoma (NC) (1 of the oral vestibule, 1 of the larynx, 1 Merkel-cell tumor of the skin and 2 medullary thyroid carcinomas). Immunoreactivity for NSE and/or CGA was always positive in all paragangliomas and NC. S-100 protein was positive in sustenticular cells in all cases of paragangliomas and focally in two cases of NC. NF and GFAP were focally positive in 3 and 2 paragangliomas respectively; and in 1 NC. CK was constantly negative in all cases of paraganglioma and constantly positive in all cases of NC. Antibody anti-CK is the single most useful immunomarker for differential diagnosis between paraganglioma, frequently benign neoplasms and NC commonly aggressive in the head and neck. These findings are consistent with the current concepts of the neuroendocrine system.

Immunohistochemical demonstration of neurone specific enolase in bone marrow infiltrated by neuroblastoma.

One hundred and two bone marrow samples were analysed by histological and immunohistochemical methods for neurone specific enolase (NSE). The biopsies were performed to determine the extent of bone marrow disease in 84 neuroblastomas, nine embryonal rhabdomyosarcomas, five Ewing's sarcomas, two cases of Hodgkin's disease and two lymphoblastic lymphomas. Twenty seven (32%) of neuroblastoma bone marrows showed metastases by conventional histological techniques and 33 (39%) after immunohistochemical staining with NSE. Five embryonal rhabdomyosarcomas, five Ewing's sarcomas, and two lymphoblastic lymphomas showed bone marrow metastases. Only one of these cases was reactive for NSE. NSE represents a very sensitive immunomarker for the follow up of neuroblastoma and improves detection of bone marrow invasion by neuroblastoma.

Case report 670: Chondroblastoma maxillary sinus.

A benign chondroblastoma of the left maxillary sinus developed in a 14-year-old girl. Roentgenographic examination showed an expanding, well-defined, calcified tumor. Facial and skull chondroblastomas may be related to primary or secondary centers of enchondral ossification, and therefore they may derive from the cartilage of growth plates [3]. Initial biopsy was inconclusive, but after surgical removal a histological diagnosis was made.

Oral and pharyngeal adenosquamous carcinoma. A report of four cases with immunohistochemical studies.

Four cases of adenosquamous carcinoma from the oral and pharyngeal cavities were analyzed by light microscopy and immunohistochemistry. Lymph node metastases were present in three cases. One patient died 2 years after treatment. All four carcinomas presented a mixture of squamous and glandular mucus-secreting neoplastic elements. Immunostaining for high-molecular-weight cytokeratins (KL1) was constantly positive in both squamous and glandular tumor cells. Antibodies against low-molecular-weight cytokeratins (K19) and carcinoembryonic antigen were positive only in the glandular component. The histological aspect and the immunohistochemical phenotype of these tumors is similar to the ordinary squamous cell carcinoma and adenocarcinoma, respectively.

Embryonal rhabdomyosarcoma arising in a mature teratoma of the testis: a case report.

We report a case of embryonal rhabdomyosarcoma present in the primary excision of an intratesticular purely mature teratoma. Testicular mature and immature teratomas are usually associated with other germ cell tumors. Nongerminal malignancies that tend to occur in gonadal and extragonadal teratomas are often epithelial. Sarcomas of all types are less frequent but embryonal rhabdomyosarcomas are encountered predominantly. This sarcomatous element can be present in the primary excision or it can appear after chemotherapy in the metastases. Usually, prognosis is dependent on the degree of aggressiveness of the sarcomatous component. A review of the literature reveals that it is unusual for an embryonal rhabdomyosarcoma to develop on purely mature teratoma. We report a case in the testicle. During followup metastases arise rapidly from the purely embryonal rhabdomyosarcomatous component. The accurate diagnosis of this unusual sarcomatous component is of paramount importance because of the implications for therapy.

Histology of the major salivary glands.

Major salivary glands are characterized by the presence of numerous excretory units that consist of acini and a peculiar duct system. Under normal conditions, sebaceous glands are annexed to the duct system in the parotid and the submaxillary glands. The excretion of the saliva is assisted by the myoepithelial cells, which play an important role in the morphology of several kinds of salivary gland tumors. Interstitial lymphocytes give rise to the formation of lymph nodes in the parotid gland. Heterotopic salivary tissue is found in many locations throughout the head and neck. Age-induced variations and reactive changes include oncocyte proliferation, fatty infiltration, squamous and mucous metaplasia, hyperplasia, atrophy, and regeneration. An analysis of the normal salivary gland structure permits a morphogenetic approach to an understanding of the variability in histologic types of salivary gland tumors.