Augusto F.G. Paulino

Basaloid Squamous Cell Carcinoma of the Head and Neck

Objective/Hypothesis Basaloid squamous cell carcinoma (BSCC), an uncommon tumor with predilection for the upper aerodigestive tract, is a distinct variant of squamous carcinoma, because of its unique histological features and ominous clinical behavior. This study reviews the experience in treating BSCC from two institutions.

Epithelial tumors of the lacrimal glands: A clinicopathologic study

We report the clinicopathologic features of epithelial tumors of the lacrimal gland apparatus, which are rare and therefore represent a major challenge for diagnosis and treatment. Histologic material from 22 lesions was studied by light microscopy, histochemistry, and immunohistochemistry. A comparison with major and minor salivary gland tumors was performed to analyze the relative distribution of these tumors and to establish whether salivary glands and lacrimal gland tumors are similar or different in their pathologic appearance and clinical behavior. There were three benign pleomorphic adenomas and 19 malignant tumors. The gender distribution was equal. The ages of the patients ranged from 10 to 73 years (mean age, 46 years). Among the malignant tumors, adenoid cystic carcinoma was the most common (nine cases), followed by mucoepidermoid carcinoma (three cases). There were two cases each of malignant mixed tumor and adenocarcinoma. All mucoepidermoid carcinomas and the adenocarcinomas were histologically high grade. There also was one case each of salivary duct carcinoma, spindle cell carcinoma, and oncocytic adenocarcinoma. Of 14 patients in whom clinical follow-up was available, seven had distant metastases and four died of their disease. The only case occurring in a child was an adenoid cystic carcinoma that recurred locally after 14 years. The clinical and pathologic features of lacrimal gland tumors resemble those lesions that arise in the intraoral minor salivary glands. The greater relative proportion of malignant cases in this series probably reflects a selection bias.

Diagnostic use of muscle markers in the cytologic evaluation of serous fluids

Differentiating reactive mesothelial cells from malignant mesotheliomas and from adenocarcinomas can be diagnostically challenging when based solely on the morphologic examination of serous fluids. The diagnosis even after the use of standard immunohistochemical stains may at times be inconclusive because of the variable reactivity of mesothelial cells for these markers. Pathologists and cytologists underutilize reactivity for desmin, a feature of mesothelial cells apparently not shared by adenocarcinomas. The purpose of this study was to evaluate the extent to which mesothelial cells express muscle differentiation and to assess the diagnostic utility of muscle markers in distinguishing reactive mesothelial cells from malignant mesotheliomas and adenocarcinomas. Archival paraffin-embedded cell blocks of serous fluids from 24 cases of reactive mesothelial cells, 14 cases of malignant mesothelioma, and 56 cases (14 cases from each) of metastatic adenocarcinoma from the lung, breast, ovary, and gastrointestinal tract were retrieved. Five cases of omentum with unremarkable mesothelial cells were also included in the study. All cases were stained for desmin, actin, myoglobin, and myogenin and evaluated independently by two observers. Strong cytoplasmic reactivity for desmin was noted in 22 of 24 cases (92%) of reactive mesothelial cells. The reactive mesothelial cells did not express actin, myoglobin, or myogenin. All cases of malignant mesothelioma and metastatic adenocarcinoma were negative for the four muscle markers. The mesothelial lining and scattered subserosal cells in the omental sections were positive for desmin. Because desmin was expressed only in benign mesothelial cells, it may serve as a reliable marker in distinguishing reactive mesothelial cells from mesothelioma or from adenocarcinoma. Awareness of this staining pattern is also important to avoid pitfalls when evaluating body fluid specimens from patients with a history of tumors expressing muscle differentiation.

TISSUE-PRESERVING APPROACH TO EXTRACTING DNA FROM PARAFFIN-EMBEDDED SPECIMENS USING TISSUE MICROARRAY TECHNOLOGY

DNA extracted from tumor cells or normal cells contained in formalin‐fixed, paraffin‐embedded tissues is widely used in many laboratories. The 2 most common procedures to isolate cells for DNA extraction from paraffin‐embedded tissues are scalpel microdissection and laser capture microdissection. A new tissue‐ and time‐conserving method for rapid DNA isolation from small cores taken from paraffin‐embedded tissue blocks is described in this report.

Malignant Melanoma of the Oral Mucosa in a 17-Year-Old Adolescent Girl

Mucosal melanomas of the oral cavity are rarely seen in the United States. The hard palate is the most common intraoral site. This unusual case occurred in the oral cavity of a 17-year-old Asian girl, who presented to her dentist with complaints of pain and swelling in the upper jaw. The lesion was distal and palatal to the maxillary left second molar, which was vital. Interestingly, the clinical presentation was a hyperplastic, tender lesion that bled when probed. Histopathologically, the biopsy demonstrated a sheet of spindle-shaped cells arranged in nests and fascicles. The nuclei were vesicular, oval to spindle-shaped, and some contained nucleoli that were distinguishable but not prominent. No melanin pigment was observed in the lesion. Tumor cells strongly expressed S100 protein, gp100 (HMB-45), and microphthalmia transcription factor, and variably expressed MART1, but not cytokeratins, CD34, or muscle-specific actin. The histopathologic features and immunohistochemical findings are consistent with a diagnosis of malignant melanoma.

Myxoid Malignant Fibrous Histiocytoma with Multiple Primary Sites

Malignant fibrous histiocytoma (MFH) is one of the most common types of soft tissue sarcomas in adults. The most common location of MFH are the extremities and the trunk, with the most common site for distant metastases being the lung. We describe a case with multiple synchronous sites of myxoid MFH but no lung metastases and presence of abnormalities of 19p13.

Epstein-Barr virus in squamous carcinoma of the anterior nasal cavity

Squamous carcinoma is the most common malignancy of the head and neck, but it rarely occurs in the nasal vestibule. Epstein-Barr virus (EBV) has been detected in and is causally linked to various head and neck tumors, particularly nasopharyngeal carcinoma. The possible role of EBV in squamous carcinoma of the anterior nasal cavity, particularly of the nasal vestibule, has not been previously investigated. Histologic sections from 17 patients with nasal vestibular squamous carcinoma were examined. Material for EBV detection by immunohistochemistry and by in situ hybridization was available in 15 of the 17 cases. The study group consisted of eight men and nine women ranging in age from 40 to 82 years (mean age, 64 years). None of the patients was of Asian descent. The squamous carcinomas were graded as well differentiated (one case), moderately differentiated (11 cases), and poorly differentiated (five cases). Fourteen patients were smokers; the history of smoking ranged from 20 to 60 pack-years. Treatment modalities included surgical resection, radiation, chemotherapy, or a combined approach. The clinical follow-up periods ranged from 7 months to 16 years. Three patients developed metastases, one of whom died of disease after 1 year. Epstein-Barr virus was not detected in any of the 15 of 17 cases tested by either immunohistochemistry or by in situ hybridization. Squamous carcinoma of the nasal vestibule is an uncommon cancer that is not causally related to EBV.