Primary giant cell tumor of soft tissue.

BACKGROUND: Primary giant cell tumor of soft tissue, also known as soft tissue giant cell tumor of low malignant potential, is a rare soft tissue tumor located in both superficial and deep soft tissue. Histologically, these lesions bear a close resemblance to their bony counterparts, giant cell tumor of bone, with round to spindle-shaped cells intimately admixed with uniformly scattered osteoclast-like multinucleated giant cells. In 1989 in the dermatology literature, two malignant giant cell tumors of soft parts were described that filled the dermis and extended into the subcutaneous tissue. METHODS: The authors report the rare occurrence of a giant cell tumor of soft tissue occurring primarily in the dermis that lacks overtly malignant features and clinically was thought to be an epidermal inclusion cyst. RESULTS: Light microscopy revealed a non-encapsulated cellular dermal tumor containing numerous osteoclast-like giant cells. Cytologic atypia was minimal and the mitotic count averaged 2-3/10 HPF. The histologic differential diagnosis is also discussed. CONCLUSION: Giant cell tumor of soft tissue is a rare neoplasm of the skin, however, recognition of this tumor is important due to its behavior as a low-grade malignancy.

Sinonasal undifferentiated carcinoma: immunohistochemical profile and lack of EBV association.

The role of Epstein-Barr virus (EBV) in the development of sinonasal undifferentiated carcinoma (SNUC) remains unresolved. Reports of EBV-positivity in SNUC may reflect inclusion of lymphoepithelioma-like carcinomas within this group. In addition, SNUC have been incompletely characterized immunohistochemically, and their undifferentiated appearance often requires such ancillary studies to aid in their distinction from other high-grade neoplasms. To address these two issues, 25 cases of SNUC diagnosed between the years 1983 and 1999 were selected from our files. EBER in situ hybridization (ISH) was performed on the paraffin-embedded tissue by using 3H-labeled EBER-1 RNA probes. Neoplasms with sufficient tissue (22 of 25) were evaluated immunohistochemically for Ki-67, p53, chromogranin, synaptophysin, placental alkaline phosphatase (PLAP), CD99, carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), neuron-specific enolase (NSE), and latent membrane protein-1 (LMP-1). The median patient age was 58 years (range, 20-81 years), with a male-to-female ratio of approximately 3:1. The most common tumor location was the nasal cavity (18 cases), followed by the ethmoid and maxillary sinuses. Median survival was 18 months. All 25 tumors were negative for EBER-I by ISH. Ki-67 was negative in one case, 1+ in nine, 2+ in six, 3+ in five, and 4+ in one. P53 was negative in nine, 1+ in five, 2+ in two, 3+ in none, and 4+ in six. CD99 expression was strongly positive in 3 of 22 (14%) and completely negative in the remainder. Variably intense focal staining for EMA was present in 4 of 22 (18%). NSE faintly stained 4 of 22 (18%). Chromogranin, synaptophysin, PLAP, CEA, and LMP-1 were negative (0 of 22). Our results suggest that EBV does not play a role in the development of SNUC. Strict histologic criteria are necessary to avoid confusion with lymphoepithelioma-like carcinoma or other high-grade malignancies in this region. The finding of occasional CD99-positive cases adds SNUC to the growing list of CD99-positive neoplasms.

Squamous cell carcinoma arising in Hailey-Hailey disease.

Hailey-Hailey disease is a recurrent, autosomal dominant vesiculobullous dermatotis with a predilection for intertrigenous areas. We report what we believe to be the first case of squamous cell carcinoma arising de novo in a skin lesion of Hailey-Hailey disease. The occurrence of malignant neoplasms arising in the skin lesions of Hailey-Hailey disease and other acantholytic dermatoses is reviewed.

KIT protein expression and analysis of c-kit gene mutation in adenoid cystic carcinoma.

The c-kit proto-oncogene encodes a transmembrane receptor tyrosine kinase (KIT), which is expressed in several normal human tissues, especially mast cells and interstitial cells of Cajal. Expression of KIT has been noted in several types of neoplasms and gene mutation has been shown as a mechanism of c-kit oncogene activation in some tumors. Recently, a single adnexal adenoid cystic carcinoma (ACC) was reported to demonstrate KIT expression, however, examination of KIT expression or c-kit mutation in ACC of salivary glands has not been performed. We examined archival tissue samples from 30 ACC of major and minor salivary glands for KIT protein expression by immunohistochemistry with a polyclonal antibody and c-kit gene mutation by polymerase chain reaction amplification and DNA sequencing. KIT protein expression was noted in 90% of ACCs. An association between the presence of at least 50% KIT positive neoplastic cells and Grade 3 ACC or a solid growth pattern was observed (P < .05). KIT expression in normal or nonneoplastic salivary gland tissue was absent. No c-kit juxtamembrane domain (exon 11) or phosphotransferase domain (exon 17) mutations were found in any of the tumors examined. In conclusion, KIT protein expression is correlated with tumor grade of salivary ACC. However, gene mutation of exon 11 or exon 17 is not a mechanism of c-kit activation in these neoplasms.

Bronchioloalveolar adenocarcinoma of lung: monoclonal origin for multifocal disease.

In an attempt to understand the histogenesis and molecular pathogenesis of multifocal bronchioloalveolar lung carcinoma (BAC) we studied 28 cases of BAC using a topographic genotyping approach for the presence of K-ras exon 1 mutations and p53 loss of heterozygosity (LOH). This analytical approach demonstrated K-ras exon 1 mutations in 12.5% of solitary BACs, 40% of BACs with microscopic or macroscopic satellite lesions, and 60% of BACs with intrathoracic metastases. In all cases with K-ras mutations, the identical point mutation was present in the primary, satellite, and intrathoracic metastatic lesions. When p53 LOH was demonstrated in the primary lesion, it was also detected in the satellites and intrathoracic metastases. No significant association was noted between the presence of K-ras mutations and p53 LOH. The results strongly support a monoclonal origin of multifocal BACs. Furthermore, the findings support the theories explaining the origin of multifocal BAC by intraalveolar route of spread, intrapulmonary lymphatic spread, or aerosolization leading to implantation at different sites. A trend toward an increased frequency of K-ras mutations and p53 LOH in BACs with satellites or metastases compared to solitary BACs was noted.

Levels of TGF-alpha and EGFR protein in head and neck squamous cell carcinoma and patient survival.

BACKGROUND: The most accurate predictor of disease recurrence in patients treated for head and neck squamous cell carcinoma is, at present, the extent of regional lymph node metastasis. Since elevated levels of epidermal growth factor receptor (EGFR) and of its ligand, transforming growth factor-alpha (TGF-alpha), have been detected in primary tumors of patients with head and neck squamous cell carcinoma, we determined whether tumor levels of these proteins were of prognostic importance. METHODS: Monoclonal antibodies specific for EGFR and TGF-alpha were used for immunohistochemical detection of each protein in tissue sections of primary tumors from 91 patients who were treated by surgical resection. Levels of immunoreactive EGFR and TGF-alpha were quantified by use of a computerized image analysis system and were normalized to appropriate standards. The logrank test and proportional hazards regression analysis were used to calculate the probability that EGFR and TGF-alpha levels were associated with disease-free survival (i.e., no recurrence of cancer) and cause-specific survival (i.e., patients do not die of their disease). All P values were two-sided. RESULTS: When tumor levels of EGFR or TGF-alpha were analyzed as continuous variables, disease-free survival and cause-specific survival were reduced among patients with higher levels of EGFR (both P = .0001) or TGF-alpha (both P = .0001). In a multivariate analysis, tumor site, tumor level of EGFR, and tumor level of TGF-alpha were statistically significant predictors of disease-free survival; in a similar analysis, regional lymph node stage and tumor levels of EGFR and of TGF-alpha were significant predictors of cause-specific survival. CONCLUSION: Quantitation of EGFR and TGF-alpha protein levels in primary head and neck squamous cell carcinomas may be useful in identifying subgroups of patients at high risk of tumor recurrence and in guiding therapy.

p53 and K-ras mutational genotyping in pulmonary carcinosarcoma, spindle cell carcinoma, and pulmonary blastoma: implications for histogenesis.

In an attempt to understand the molecular pathogenesis of biphasic pulmonary neoplasms, the authors studied 25 cases of carcinosarcoma, spindle cell carcinoma, and pulmonary blastoma using a combined immunohistochemical and topographic genotyping approach for the presence of p53 abnormalities within the different epithelial and mesenchymal components of these tumors. Genotyping involved a search for point mutational damage in p53 exons 5-8, which was correlated with p53 immunoreactivity. This analytical approach demonstrated p53 missense point mutations in four of nine cases of spindle cell carcinoma with a 100% concordance rate between p53 immunopositivity and the presence of DNA mutational damage. One of six carcinosarcomas, heterologous in type, exhibited a p53 mutation. The concordance rate among carcinosarcomas was also 100%. However, the concordance rate among classic biphasic pulmonary blastomas was only 43%, with one of seven cases demonstrating a p53 mutation by DNA genotyping. The lack of concordance in pulmonary blastomas was possibly due to the existence of genotypically distinct subsets of tumor cells likely bearing mutations among largely nonmutated cells. In a similar fashion, among three well-differentiated fetal type adenocarcinomas, no p53 mutations were detected despite the presence of focal p53 immunopositivity in one of the cases. No K-ras mutations were detected in any of the 25 tumors examined. Monoclonal histogenesis from a single totipotential cell in a subset of these neoplasms (six of 22 cases) was supported by the finding of p53 overexpression and identical p53 mutational genotype in both the epithelial and spindle elements of the tumors. Furthermore, the finding of a small percentage of p53-positive tumor cells within one or both components suggests late acquisition of p53 mutational change in a subset of pulmonary blastomas.

Calreticulin biosynthesis and processing in human myeloid cells: demonstration of signal peptide cleavage and N-glycosylation.

Calreticulin is a soluble endoplasmic reticulum protein comprising the major storage reservoir for inositol trisphosphate-releasable calcium. Although its highly conserved primary structure and a wide range of functions have been well described, less attention has been paid to its biosynthesis, particularly in human tissues. We report analyses of synthesis, proteolytic processing and glycosylation of human calreticulin. In both HL-60 and PLB-985 myeloid cell lines calreticulin was immunoprecipitated as a single 60-kD species without evidence of precursor forms. However, in vitro cell-free synthesis produced a 62-kD primary translation product, which in the presence of microsomal membranes, was processed by cotranslational signal peptide cleavage to a 60-kD species that comigrated with mature calreticulin produced in myeloid cells. Neither tunicamycin treatment of the cells nor endoglycosidase digestion of calreticulin resulted in any forms other than the 60-kD protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, suggesting that the potential site for N-glycosylation at asparagine-327 was unmodified. However, oxidative derivatization of carbohydrate components with digoxigenin showed that human calreticulin produced in either HL-60 cells or Sf9 insect cells is glycosylated, indicating that glycosylated and nonglycosylated human calreticulin have indistinguishable electrophoretic mobilities. Direct measurement by phenol-H2SO4 confirmed the presence of carbohydrate on recombinant human calreticulin. These data show that human myeloid calreticulin undergoes cotranslational signal peptide cleavage and posttranslational N-linked glycosylation. Although glycosylation of calreticulin has been shown in rat liver and bovine liver and brain, it has been reported to be lacking in other tissues including human lymphocytes.

Aggressive gastric peripheral T-cell lymphoma of CD8+ type associated with lymphomatous meningitis.

Most gastric lymphomas are of B-cell origin, and many are either low-grade or high-grade B-cell lymphomas of mucosa-associated lymphoid tissue type. Gastric T-cell lymphomas are very rare, usually of CD4+ type, and few have had genotypic studies. We report the case of a gastric peripheral T-cell lymphoma of CD8+ type. Genotypic studies demonstrated partial deletion with rearrangement of the T-cell receptor beta-chain gene. Lymphomatous meningitis developed, and the patient died after only 2 months despite chemotherapy. The case is compared with the other gastric T-cell lymphomas that have been reported.