Jorge Esquiche León

Immunohistochemical expression of p16, p21, p27 and cyclin D1 in oral nevi and melanoma.

The acquisition of abnormalities at G1/S is considered a crucial step in the genesis and progression of melanoma. The expression of cell cycle regulators has also been used in various neoplasms as an adjunct to diagnosis. The aim of this study was to compare the expression of p16, p21, p27 and cyclin D1 in oral nevi and melanomas. Expression of these cell cycle regulatory proteins was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas. p16 and p27 were highly expressed in intramucosal nevi, whereas p21 and cyclin D1 expression was higher in oral melanomas. The results indicate that p21 and cyclin D1 may be involved in the development of oral melanomas, and eventually they may be useful in the differential diagnoses of oral benign and malignant melanocytic lesions.

Nonlymphoid mesenchymal tumors of the parotid gland

Salivary gland tumors are uncommon and most of them are of epithelial origin. Mesenchymal tumors affecting the parotid are extremely rare, and we present a series of 19 cases. All parotid tumors (600 cases) treated at the Department of Head and Neck Surgery from A.C. Camargo Hospital, Brazil from 1953 to 2003 were reviewed and 19 cases of nonlymphoid mesenchymal origin were selected. The histological characteristics were reviewed and clinical features were obtained from the medical charts. 15 out of 19 were benign tumors, including 5 lymphangiomas, 5 neurofibromas, and one case each of schwannoma, lipoma, solitary fibrous tumor, meningioma and giant cell tumor. Four malignant tumors were classified as rhabdomyosarcoma, fibrosarcoma, Langerhans cell histiocytosis and endodermal sinus tumor. From the malignant cases, only the patient with fibrosarcoma died due the tumor, the other three are alive with no signs of recurrence. In our series of 600 cases of parotid gland tumors, nonlymphoid mesenchymal tumors corresponded to 3.16% (19 cases; 15 benign and 4 malignant). All cases were treated by surgery with no recurrences, except one case of fibrosarcoma whose patient died of distant metastasis.

Primary oral melanoma: a histopathological and immunohistochemical study of 22 cases of Latin America.

Objective: The aim of this study was to analyze the histopathological and immunohistochemical characteristics of 22 cases of primary oral melanomas (OM). Study Design: Twenty two cases of primary oral melanoma were analyzed by description of their histopathological features and immunohistochemical study using the antibodies S-100, HMB-45, Melan-A and Ki-67. Results: The mean age was 58 years and 14 cases were female. The main affected sites were the hard palate, followed by the upper gingiva. Microscopically, 15 cases presented level III of invasion, 2 cases were amelanotic and 13 showed a mixed epithelioid and plasmacytoid or spindle cells composition. Some cases showed necrosis, perivascular and perineural invasion. S-100 and HMB-45 were positive in all cases, but 3 cases were negative for Melan-A. The proliferative index with Ki-67 was high, with labeling index ranging from 15.51% to 63% of positive cells. Conclusion: S-100 and HMB-45 are more frequently expressed than Melan-A in primary oral melanomas and these markers are helpful to confirm the diagnosis. Key words:Oral melanoma, histopathology, immunohistochemistry.

Expression of fatty acid synthase (FASN) in oral nevi and melanoma

OBJECTIVE The aim of this study was to determine the expression of fatty acid synthase (FASN) in oral nevi and melanomas, comparing the results with correspondent cutaneous lesions. MATERIALS AND METHODS Expression of FASN was evaluated by immunohistochemistry in 51 oral melanocytic lesions, including 38 intramucosal nevi and 13 primary oral melanomas, in 10 cutaneous nevi and in 14 melanomas. RESULTS Fatty acid synthase was strongly expressed only in melanomas, either of the oral mucosa or cutaneous. On the other hand, most oral and cutaneous nevi were negative, with a few oral cases showing focal and weak expression. CONCLUSION Fatty acid synthase is expressed in malignant melanocytes, and it can be a helpful marker to distinguish oral melanomas from oral melanocytic nevi.

Lingual cyst with respiratory epithelium: a histopathological and immunohistochemical analysis of two cases

Cysts of the tongue are rare, usually derived from epithelia of the embryonic gastrointestinal and respiratory tracts, and classified according to the predominant epithelium lining. These cysts are usually discovered during infancy, more frequently in males, but they may not appear until well into adulthood. The authors report two lingual cysts lined mainly with respiratory, and focally by squamous, epithelium. Periodic acid-Schiff and mucicarmine staining revealed focal positivity in intracystic mucoid material and goblet cells. Immunohistochemical analysis with vimentin, cytokeratins (AE1/AE3, 34betaE12, CK1, CK5, CK6, CK7, CK8, CK10, CK13, CK14, CK16, CK18, and CK19), E-cadherin, beta-catenin, and epithelial membrane antigen showed a similar profile of normal respiratory epithelium, suggesting well-differentiated states. Owing to their controversial origin, these cysts should be named descriptively, as suggested by Manor et al., as lingual cysts with respiratory epithelium.

Head and neck amyloidosis: clinicopathological features and immunohistochemical analysis of 14 cases

BACKGROUND Amyloidosis is associated with or caused by amyloid deposition. These fibrillar proteins may be deposited extracellularly causing tissue damage or impairment. OBJECTIVES The aim of the study was to retrospectively review pathology archives in two oral diagnostic centers for cases fulfilling criteria of amyloidosis and to differentiate AA and AL types of amyloidosis. METHODS The clinicopathological features, alkaline Congo red staining, with and without pretreatment with potassium permanganate, and immunohistochemical (IHC) staining with anti-AA, anti-kappa (κ), and anti-lambda (λ) light chain antibodies were carried out and analyzed. RESULTS The search identified 14 cases. Ten patients were women and four were men, with a mean age of 58 years. Eleven patients had systemic involvement by amyloidosis (associated either with multiple myeloma or plasma cell dyscrasia/monoclonal gammopathies), while three presented the localized type, one of them associated with plasmacytoma. All cases showed positivity for κ or λ light chains (AL-amyloid) and presented resistance to the potassium permanganate pretreatment. CONCLUSIONS Our results show that the head and neck region is preferentially affected by systemic AL-amyloidosis, usually associated with plasma cell dyscrasia. Interestingly, two cases affected by inflammatory rheumatic diseases presented AL-amyloid deposition. Moreover, even after pretreatment with potassium permanganate, which was helpful in highlighting the presence of AL-amyloid, in agreement with the IHC findings, clinical classifications should be carefully made in systemic amyloidosis.

Pigmented villonodular synovitis of the temporomandibular joint: case report and review of the literature

Pigmented villonodular synovitis (PVNS) is an aggressive proliferative lesion that usually involves the synovial tissues of big joints. To date, there are ∼52 cases of PVNS affecting the temporomandibular joint reported in the English-language literature, about one-third of them exhibiting intracranial involvement. We herein describe an additional case of PVNS of the temporomandibular joint with skull base invasion affecting a 26-year-old male patient and discuss its clinicopathologic features considering previously published cases. Histopathology and imaging evaluation are important for the diagnosis of PVNS, which should be included in the differential diagnosis of preauricular aggressive swellings.

Biocompatibility of sealers used in apical surgery: a histological study in rat subcutaneous tissue

The aim of this study was to evaluate the biocompatibility of sealers used in apical surgery in rat subcutaneous tissue. Sterile polyethylene tubes were filled with the following sealers: Sealapex, Sealapex with addition of zinc oxide, Sealer 26, Sealer 26 with thicker consistency (greater powder-to-resin ratio) and White MTA. The tubes were implanted in the dorsum of male rats and after 7, 21 and 42 days, the animals were killed, obtaining 5 specimens for each sealer in each evaluation period. The lateral surface of the tube was used as negative control. The inflammatory reaction to contact with the sealers was classified as absent, mild, moderate and severe. At 7 days, all sealers caused similar inflammatory reactions in the connective tissue of the animals, with most specimens presenting a moderate to intense chronic inflammatory reaction, with presence of multinucleated giant cells. At 21 days, Sealer 26 and Sealer 26 with thicker consistency presented more intense inflammatory reaction (p=0.004), whereas after 42 days, the inflammatory reaction ranged from absent to mild with statistically similar results for both materials (p=0.08). Except for MTA, all sealers presented foreign-body granulomatous reaction at 42 days. All sealers but Sealapex presented a statistically significant decrease of the inflammatory reaction over time. In conclusion, all sealers caused moderate to severe inflammation in the earlier evaluation period. However, Sealer 26 and Sealer 26 with thicker consistency caused more intense inflammatory reactions after 21 days of contact with the tissues and no granulomatous reaction was observed for MTA at the final period of analysis.

Expression of minichromosome maintenance 2, Ki-67, and geminin in oral nevi and melanoma.

Evaluation of cell cycle using antibodies against nuclear proteins involved in regulating DNA replication has gained special interest in the effort to predict biologic behavior of benign and malignant tumors. The aim of this study was to analyze the expression of minichromosome maintenance 2, Ki-67, and geminin in oral nevi and melanomas. Expression of these cell proliferation markers was evaluated by immunohistochemistry in 49 oral melanocytic lesions, including 38 intramucosal nevi and 11 primary oral melanomas. The labeling index of each proliferation marker was assessed considering the percentage of cells expressing nuclear positivity out of the total number of cells, counting 1000 cells per slide. Minichromosome maintenance 2, Ki-67, and geminin were rarely expressed in intramucosal nevi, in contrast to oral melanomas, which showed high levels of these cell proliferation markers, particularly minichromosome maintenance 2, indicating it is a more sensitive marker in primary oral melanomas than Ki-67 and geminin. These results indicate that these markers may be involved in the pathogenesis of oral melanomas and could be eventually useful as an additional diagnostic tool for differential diagnosis of oral benign and malignant melanocytic lesions.

EBV-Associated Polymorphic Posttransplant Lymphoproliferative Disorder Presenting as Gingival Ulcers

Posttransplant lymphoproliferative disorders (PTLDs) present a wide clinicopathological spectrum, varying from the usual Epstein-Barr virus (EBV)-driven infectious mononucleosis-type polyclonal proliferations to EBV-positive or EBV-negative proliferations indistinguishable from overt lymphomas that occur in immunocompetent individuals. PTLDs characteristically have a predilection for extranodal sites and association with EBV.These disorders are usually B-cell type, although T-cell and rare cases involving both T- and B-cell types have also been described. The initial treatment consists in decreasing the immnosupressive therapy, usually with favorable results. The authors report on a rare case of a 19-year-old girl, with post—renal transplantation EBV-associated polymorphic lymphoproliferative gingival ulcerated lesions. To the best of their knowledge, this is the first case described in the English-language literature of polymorphic PTLD involving both B-cell and T-cell lineages, with an unusual immunoprofile affecting the mouth. The authors warn that this condition could be easily misdiagnosed as malignant lymphoma if not properly recognized.