Spontaneous regression of plasmablastic lymphoma in an elderly human immunodeficiency virus (HIV)-negative patient.

Plasmablastic lymphoma (PBL) is an aggressive lymphoma commonly associated with human immunodeficiency virus (HIV) infection. Herein we describe a rare case of PBL that spontaneously regressed. An 80-year-old man was referred to our hospital owing to an exophytic gingival tumor in the right maxillary second molar region. He had no significant past medical history, and a screening test for HIV was negative. Imaging showed that the tumor measured 26 × 23 × 16 mm and was confined in the alveolar bone. The tumor was histologically comprised of highly proliferative immunoblastic cells positive for CD138 and Epstein-Barr virus (EBV)-encoded RNA. Monoclonal IgH chain gene rearrangement was detected via polymerase chain reaction. After biopsy and diagnosis of PBL, the tumor began to decrease in size and had apparently disappeared at the time of surgery. There was no histological evidence of a residual lesion in the surgical specimen. In conclusion, a minority of immunosenescence-associated PBLs in the elderly should be recognized as a unique clinicopathological entity distinct from common aggressive PBL.

Gingival rhabdomyosarcoma in an adult: a unique entity.

Rhabdomyosarcoma is a disease that predominantly affects children. Approximately 40 per cent are located in the head and neck region but it is rare in the oral cavity. This article describes an interesting case of an embryonal rhabdomyosarcoma in a 36-year-old male, involving the mandibular gingiva. The lesion showed radiolucency with ill-defined margins that was crossing the midline. The history revealed a similar lesion six months back at the same site and the lesion had been completely excised. The biopsy reports confirmed the diagnosis of embryonal rhabdomyosarcoma after which en-bloc resection of the tumor was performed with administration of chemotherapy and radiotherapy. Due to high recurrence rate of rhabdomyosarcomas in adults, multimodal therapy should be planned for proper care of the patient. Clinical, radiological, histopathological and management aspects are discussed here.

Immunohistochemical profile of oral mucosal and head and neck cutaneous melanoma.

BACKGROUND: In addition to ultraviolet radiation exposure, various molecular markers may differ between oral mucosal and cutaneous head and neck melanomas and lead to variations in their biologic behavior and prognosis. The aim of this study was to compare four such markers, namely microphthalmia transcription factor (MITF), P75, P53, and Ki-67 in malignant melanomas originating from the oral cavity and head and neck skin. METHODS: A total of 19 oral mucosal and 23 head and neck cutaneous melanomas were subjected to immunohistochemical analysis using antibodies against MITF, P75, P53, and Ki-67. Statistical comparison of data was performed by t-test and chi-square analysis (P < 0.05). RESULTS: Significant differences in MITF (P = 0.016) and Ki-67 (P = 0.002) were observed between oral mucosal and cutaneous melanomas. P75 (P = 0.80) and P53 (P = 0.76) did not differ significantly, between these locations. CONCLUSIONS: According to the results obtained in this study, the biological properties of cutaneous and mucosal melanoma differ, especially regarding MITF and Ki-67.

Primary neuroendocrine carcinoma in oral cavity: two case reports and review of the literature.

Neuroendocrine carcinoma (NEC) is a tumor that occurs in different locations, particularly the lungs and larynx. The oral cavity is a rare site for a primary NEC. This report describes 2 cases of primary NEC in the oral cavity. Case 1 occurred in the anterior mandibular gingiva in a 25-year-old woman and presented with a special histologic appearance. This patient showed no evidence of recurrence 13 months after marginal resection of the anterior mandible. Case 2 was a primary NEC with some foci of squamous cell differentiation arising in the right buccal region in a 38-year-old woman. This patient showed no evidence of disease 8 months after tumor resection and postoperative iodine-125 brachytherapy. To the best of the authors' knowledge, case 1 is the youngest patient with NEC reported in the oral cavity to date in the English-language literature, and case 2 is the first report of a primary NEC in the buccal region.

Immunohistochemical features of 3,3',4,4'-tetrachloroazobenzene-induced rat gingival lesions.

Gingival lesions of squamous hyperplasia, cystic keratinizing hyperplasia (CKH), and squamous cell carcinoma (SCC) can be induced in rats treated by chronic gavage with 10-100 mg/kg 3,3',4,4'-tetrachloroazobenzene. We evaluated gingival squamous hyperplasia (GSH), CKH, and SCC for the immunohistochemical pattern of expression of carcinogenesis-associated markers. The 3 types of lesions and controls were stained with proliferation markers (proliferating cell nuclear antigen [PCNA] and cyclin-D1), tumor-suppressor markers (ß-catenin and mammary serine protease inhibitor [maspin]) and stroma-related markers (α-smooth muscle actin [SMA] and osteonectin/SPARC). The lesions had common immunohistochemical characteristics that differed in their expression patterns among the various diagnoses. PCNA and cyclin-D1 expression was higher in GSH, CKH, and SCC than in controls. The normal membranous expression of ß-catenin was lower in GSH, and almost absent in CKH and SCC. Maspin expression was similar in GSH and controls, whereas both CKH and SCC showed decreased expression. SMA and/or osteonectin/SPARC were seen in stromal cells in CKH and SCC. Collectively, there appears to be a progression from hyperplastic and cystic lesions toward malignancy based on the morphological changes, supported by the expression of carcinogenesis-associated proteins. The exact sequence of events leading to SCC remains to be defined in a time-dependent manner.

A rare case of oral epithelioid sarcoma of the gingiva.

Epithelioid sarcoma (ES) is a rare malignant soft tissue tumor. ES can be classified into proximal, distal, and fibroma-like subtypes. These tumors show both mesenchymal and epithelial immunophenotypes. Microscopically, the proximal type ES is usually characterized by nodules of spindle and epithelioid cells growing in granuloma-like pattern often presenting with central necrosis. Immunohistochemically these tumors are vimentin, pancytokeratin, and usually EMA (80%) positive. CD34 (50%) and CD99 (25%) may be positive, and occasionally SMA and S-100 immunopositivity has been reported. No specific genetic alterations have been found in ES. As far as we know, this is the first case in the literature to present ES in gingival mucosa.

Evaluation of MMP-1, MMP-10, TIMP-1, a-SMA and TGF-b1 in angiofibromas of tuberous sclerosis.

AIM: Tuberous sclerosis is a neurocutaneous syndrome characterized by affect multiple organs such as brain, kidneys, heart, eyes, lungs and skin. The aim of this study was to analyze the pattern of immunolocalization of markers MMP-1, MMP-10, TIMP-1, α-SMA and TGF-ß1 in oral and facial angiofibromas in individuals affected by tuberous sclerosis. METHODS: Microscopical analyses on hematoxilin-eosin and immunohistochemistry reactions were performed to analyze the previously cited biological markers pattern in orofacial angiofibromas. RESULTS: Reactivity was observed for MMP-1, MMP-10 and TGF-ß1, in addition to negative for TIMP-1 and α-SMA, except perivascular and epithelial staining for this. Concerning the intensity, a strong marking for MMP-1 in the basal layer of the epithelium, and a slight positivity in the suprabasal layers predominated. MMP-10 was slightly expressed in all epithelial layers. The connective tissue showed slight to moderate reactivity for MMP-1 and MMP-10. TIMP-1 demonstrated slight to moderate marking in the various layers of a single lesion and to TGF-ß1 expression showed varied in intensity staining both between lesions and between tissue layers. CONCLUSION: MMP-1, MMP-10 and TGF-ß1 exhibited reactivity in oral and cutaneous angiofibromas with heterogeneous distribution patterns among both tissue elements analyzed in the intensity of marking the same among the specimens. TIMP-1 showed reactivity predominantly negative in the specimens analyzed and α-SMA presented restricted to epithelial and perivascular regions of these lesions.

Congenital granular cell lesion: clinical, microscopic and immunohistochemical aspects in a case of multiple lesions.

Congenital granular cell lesion of the newborn, also known as congenital epulis, is a rare benign oral cavity tumor presenting at birth. Usually, it appears as a solitary mass arising in the mouth and originates from the anterior alveolar ridge. The objective of the present article is to report a case of congenital granular cell lesion in an 8-day-old female newborn. The patient presented four intraoral pedunculated lesions. Diagnosis, treatment, microscopic and immunohistochemical characteristics are also discussed.

Solitary neurofibroma of the gingiva with prominent differentiation of Meissner bodies: a case report.

BACKGROUND: Oral neurofibromas are peripheral nerve sheath tumors, similar to schwannomas. Histological variations in oral neurofibromas are relatively uncommon. CASE PRESENTATION: Here, we present a case of unique variation in the observed characteristics of a neurofibroma, with no relation to neurofibromatosis type-1 or von Recklinghausen disease of the skin. The neurofibroma was observed in the right mandibular gingiva of a 32-year-old Japanese woman. Histologically, it differed from conventional neurofibromas in that the tumor was composed of a mixture of fine fibrillary collagen in sheets and/or cords of neoplastic Schwann cells containing numerous clusters of Meissner bodies. Histologically, these bodies were in contact with neoplastic Schwann cells. The Meissner bodies were immunopositive for S-100 protein, neuron-specific enolase, and vimentin, but were negative for calretinin. CD34-positive spindle cells were observed around the Meissner bodies. No recurrence or signs of other tumors have been observed in the patient for 5 years after tumor resection. CONCLUSION: To the best of our knowledge, no formal descriptions of sporadic, solitary neurofibromas containing numerous Meissner bodies occurring in the oral cavity are available in literature. We believe that an uncommon proliferation of Meissner bodies, as seen in the present case, may result from aberrant differentiation of neoplastic Schwann cells.

Congenital epulis.

Congenital epulis of the newborn is a very rare and unique tumor first described in 1871 by Neuman. It has a female predilection. It is a tumor with no tendency to recur after excision. The histogenesis of the lesion is unknown, but it is believed to be of mesenchymal origin. We report a 2-day-old female with tumor mass on the anterior mandibular alveolar ridge, which demonstrated immunoreactivity for vimentin, S-100 and neuron-specific enolase; thus, suggesting a similar histogenesis with granular cell tumor.

Ossifying fibromyxoid tumor in the mandibular gingiva: case report and review of the literature.

BACKGROUND: Ossifying fibromyxoid tumors (OFTs) are uncommon soft tissue neoplasms. Only one case arising in the gingiva has been described. METHODS: A 21-year-old woman presented with a painless exophytic mass located in the right posterior mandibular gingiva, which was identified 6 months earlier. Radiographs showed irregular calcifications inside the lesion, discrete irregularity of alveolar bone, and integrity of buccal and lingual cortical bone. An incisional biopsy was performed based on the clinical diagnostic hypothesis of peripheral ossifying fibroma or peripheral giant cell granuloma. Microscopic features were compatible with the diagnosis of ossifying fibroma. The entire mass was excised and submitted to histopathologic and immunohistochemical analysis. RESULTS: Histopathologic analysis revealed proliferation of round to spindle-shaped cells arranged in cords and nests and embedded in a fibromyxoid matrix. An incomplete shell of bone trabeculae located beneath the fibrous pseudocapsule was observed at the periphery. Immunohistochemical analysis showed positivity for vimentin and S-100 protein and negativity for smooth muscle actin, muscle-specific actin, and glial fibrillary acidic protein. The definitive diagnosis was OFT. The patient showed no clinical signs of recurrence 7 months after surgical excision. CONCLUSIONS: OFTs located in the gingiva are extremely rare. At this site, these tumors are clinically indistinguishable from other reactive or neoplastic lesions. Although many cases present an indolent biologic behavior, the local recurrence of OFTs has been reported; therefore, long-term follow-up is mandatory.

Low-grade gingival leiomyosarcoma in a child.

Leiomyosarcoma (LMS) of the oral cavity, a rare mesenchymal tumor exhibiting smooth-muscle differentiation, is extremely uncommon in childhood. The most frequent location of childhood LMS is the gastrointestinal tract, particularly the stomach. The purpose of this paper is to report a case of leiomyosarcoma affecting the gingival tissues and mandible of a 9-year-old girl with peculiar clinical, microscopic, and radiographic features. Clinical and radiographical examinations revealed a gingival growth affecting the primary mandibular right first molar with inflammatory features. The lesion was initially suspected to be pyogenic granuloma and was removed by excisional biopsy. Microscopic findings showed a hypercellular proliferation of mesenchymal spindle cells, suggesting malignant spindle cell neoplasm. Immunohistochemical, histochemical, and radiographic studies were undertaken, and the final diagnosis established was a low-grade leiomyosarcoma in the gingiva.

Oral myofibromas: report of two cases and review of clinical and histopathologic differential diagnosis.

Myofibroma is a benign mesenchymal neoplasm composed of myofibroblasts which has been described with different synonyms since the first report in 1951. It may show clinical and histologic features that may be misinterpreted as a malignancy. We describe 2 cases of oral myofibromas affecting infants; the first one showed a rapid growth with teeth displacement and ulceration; the second one presented a relatively slow growth with an indolent course. Differential diagnosis included benign and malignant mesenchymal neoplasms, salivary gland tumors, and reactive processes. Microscopic analysis of both lesions revealed a spindle cell tumor with immunoreactivity for vimentin, muscle-specific actin, and specific smooth muscle isoform alpha-actin, rendering the diagnoses of myofibroma. The patients were treated with surgical excision, and both are in follow-up without any signs of recurrence. Myofibroma presents a wide range of differential diagnosis, including benign and malignant neoplasms. Therefore, accurate diagnosis may avoid an unnecessary aggressive therapy.

Quantification of CD44v6 and EGFR expression in head and neck squamous cell carcinomas using a single-dose radioimmunoassay.

BACKGROUND: In the growing field of tumor targeting, there is an urgent need to profile suitable molecular targets. In this study, CD44v6 and EGFR expression was quantified in samples of patients with head and neck squamous cell carcinoma (HNSCC) using a single-dose (SD) radioimmunoassay. METHODS: The SD radioimmunoassay using 125I-chimeric monoclonal antibody (cMAb) U36 and 125I-cMAb cetuximab was first validated and then applied to quantify the expression of their target antigen molecules, CD44v6 and EGFR, in patient samples. Results were compared to immunohistochemical staining. RESULTS: The SD assay provided sensitive quantitative values of the molecular targets studied, generally agreeing with the immunohistochemistry (IHC) results. The results indicated that expression of CD44v6 (0.2-20 nmol/mug membrane) was generally higher than that of EGFR (0.6-2.3 nmol/microg membrane) in the tumor samples analyzed, which corresponded to an average of 700,000 and 90,000 antigen molecules per cell, respectively. CONCLUSIONS: The SD radioimmunoassay is simple, reliable, and can be performed on a small amount (50 mg) of tissue. This assay could be a useful tool in the growing field of personalized cancer therapy, and can be used as a complement to IHC. In the tumors studied, CD44v6 was generally expressed at a higher level than EGFR, which might suggest that it could be more readily targeted by MAbs.

Oral leiomyosarcomas: report of two cases with immunohistochemical profile.

Leiomyosarcoma of the oral cavity is a very rare tumor associated with aggressive clinical behavior and low survival. In this paper, we report 2 cases of leiomyosarcoma, affecting the gingival mucosa of a 54-year-old female and the maxillary bone of a 63-year-old male. Histologically, the tumors were composed of variably oriented fascicles of spindle-shaped cells with cigar-shaped nuclei and eosinophilic cytoplasm. The lesions were treated by surgical resection. Immunoreactivity to anti-vimentin, anti-smooth muscle actin, anti-desmin, anti-laminin, and anti-muscle-specific actin antibodies were found; conversely, the tumor cells were negative for anti-S100 and AE1/AE3 proteins. This report emphasizes the role of immunohistochemical study for correct diagnosis of leiomyosarcoma.

Clear cell carcinoma of the mandibular gingiva 'minor salivary gland': a case report with immunohistochemical study.

Clear cell carcinoma is a rare neoplasm that arises in salivary glands. They are more frequent in the intraoral minor salivary glands than the major salivary glands. The present case involved a 44-year-old Japanese man with a slight reddish swelling on the mandibular gingiva. Initial clinical diagnosis was squamous cell carcinoma based on this erythroplakial lesion. All tumor cells displayed the expected pattern of immunoreactivity, with positive results for pancytokeratin and high molecular weight cytokeratin. This report examined the immunohistochemical characteristics of clear cell carcinoma, minor salivary gland, and reviewed the existing literature.

Establishment and characterization of a spindle cell squamous carcinoma cell line.

BACKGROUND: Spindle cell squamous carcinoma (SCSC) is a rare and peculiar biphasic malignant neoplasm that occurs mainly in the upper aerodigestive tract. It consists of sarcomatoid proliferation of pleomorphic spindle-shaped cells and squamous cell carcinoma. METHODS: Here, we established a SCSC cell line from a tumour arisen in gingiva. We characterized the feature of a SCSC cell line by immunohistochemistry. To know the biological feature, we examined the cell growth, invasiveness and epithelial-mesenchymal transition markers of a SCSC cell line in comparison with oral squamous cell carcinoma (OSCC) cell lines. RESULTS: By immunohistochemical analyses, the primary tumour expressed cytokeratin and vimentin, indicating carcinosarcoma-like characters. This tumour also showed overexpression of p53 protein. Cultured SCSC cells resulted in bypass of crisis and maintenance over passage 100. The established SCSC cell line was spindle-shaped and showed identical immunohistochemical characters to those of primary tumour cells. Similar to the primary tumour, the cell line showed p53 overexpression and had p53 mutation at codon 132: AAG (lys)-->AAT (asp). The SCSC cell line grew slower than two other OSCC cell lines (MSCC-1 and HSC-2), whereas SCSC cells had remarkable invasiveness in comparison with these cell lines. Moreover, SCSC cells expressed wnt-5a and vimentin mRNA at high levels, but did not express E-cadherin mRNA. This expression pattern of the markers was similar to that of mesenchymal cells, not of epithelial cells. CONCLUSION: In the present study, we newly established a SCSC cell line with strong invasiveness. This is the first report on the establishment of SCSC cell line. The SCSC cell line can be a useful cell model for the study to know the cytodifferentiation and nature of SCSC.