Luciana Yamamoto Almeida

Focal osteoporotic bone marrow defect mimicking a mandibular cystic lesion.

An unusual presentation of a focal osteoporotic bone marrow defect (FOBMD) of the mandible mimicking a cystic lesion is documented. A definitive diagnosis could be established only on the basis of the histopathologic evaluation. A 66-year-old Brazilian woman was referred by her dentist for well-defined radiolucency of the mandibular molar region suggesting a cystic lesion of odontogenic origin. The computed tomography scan confirmed that the lesion did not affect the corticals. The biopsy confirmed the diagnosis of FOBMD. The diagnostic difficulty in the current case is obvious, because FOBMD, usually exhibiting an ill-defined radiolucency, is seldom suspected preoperatively when a differential diagnosis is considered for focal well-defined radiolucent areas in the jaws.

Cryotherapy for localized juvenile spongiotic gingival hyperplasia: preliminary findings on two cases

BACKGROUND Localized juvenile spongiotic gingival hyperplasia (LJSGH) is a distinct subtype of inflammatory gingival hyperplasia that shows lack of response to traditional periodontal treatment, and after surgical excision, recurrence rate of 6-16% has been reported. CASE REPORT Two girls (11- and 9-year-old) with multifocal red patches along the maxillary and mandibular labial gingiva showed no regression of the lesions after basic periodontal treatment. Surgical excision of focal lesion in each case was performed, which showed typical features of LJSGH. In both cases, the lesions presented recurrence. Hence, cryotherapy sessions in all lesions were performed. CONCLUSION Cryotherapy appears to be successfully in LJSGH and well received by paediatric patients.

Multiple Desmoplastic Cellular Neurothekeomas in Child: Report of the First Oral Case and Review of the Literature

Cellular neurothekeomas (CNs) are distinctive benign tumors of uncertain histogenesis, with predilection for the skin of the head and neck region. We describe the first case of multiple desmoplastic CNs (DCNs) affecting the oral cavity in a 9-year-old girl. Histopathologic evaluation showed a proliferation of spindle and epithelioid cells, forming nests and bundles, supported by exuberant fibrous stroma, as well as scattered multinucleated floret-like giant cells. The tumor cells were immunopositive for vimentin, CD63, CD56, whereas AE1/AE3, S100, CD34, α-SMA, GFAP, EMA, CD57 and NSE were negative. Ki-67 was <2%. Multiple DCNs should be considered in the differential diagnosis of oral nodular lesions.

Surgical Management of Traumatic Peripheral Osteoma of the Mandible

Osteomas are benign osteogenic lesions that result from the proliferation of mature bone. Three variants are known: central, peripheral, and extraskeletal. The peripheral variant is the most common and it most frequently affects the paranasal sinuses, rarely occurring in the jaws. This article describes the case of a 33-year-old white male patient who was referred complaining of facial asymmetry. Clinical examination revealed an increase in volume at the base of the right side of the mandible, hard bony consistency and well delimited, painless to the touch, without signs of infection or intraoral alterations. Radiographic examination revealed an oval lobulated, radiopaque sessile lesion adhered to the mandibular base near the insertion of the masseter muscle. The patient reported practicing martial arts many years ago. Owing to the limited access, it was decided to perform the complete lesion removal through an extraoral surgical approach, by using a skin crease in the upper neck region below the lesion. The patient recovered well and the histopathological analysis confirmed the diagnosis of osteoma. The etiopathogenesis of osteoma is not completely elucidated, and 3 theories are more accepted: developmental defect, neoplastic nature, and reactive lesion owing to trauma or local infection. The clinicopathological correlation in the present case supports a traumatic origin. Traumatic peripheral osteoma should be considered in the differential diagnosis of nodular bone-forming lesions affecting the mandible.

EBV-Negative Lymphoepithelial-Like Carcinoma of the Lower Lip: Immunohistochemical and in Situ Hybridization Analyses

Lymphoepithelial-like carcinoma (LEC) is a rare malignant neoplasm, which can be associated with Epstein-Barr virus (EBV) infection. Histologically, LEC is an undifferentiated carcinoma with an intermixed reactive lymphoplasmacytic infiltrate. LEC appears to be an uncommon tumor type of lip carcinoma. An 82-year-old white woman presented a lesion on her lower lip that developed over the last year. The lesion was characterized by ulceration with flat edges, hardened base, painful, and absence of regional lymphadenopathy. Microscopical analysis evidenced an intense inflammatory infiltrate, composed of lymphoplasmacytic cells, associated with scarce pleomorphic epithelial cells. Immunohistochemistry highlighted the LEC cells with strong expression of pan-CK AE1/AE3, EMA, p63, and p53. CD138 was also faintly positive. Ki-67 was >85%. In situ hybridization analysis did not show evidence of EBV. A diagnostic of EBV-negative LEC was made. We present an uncommon type of lip carcinoma, which can represent a diagnostic challenge for clinicians and pathologists.

Immune cell infiltration in Ectomesenchymal chondromyxoid tumor: An immunohistochemical study

Ectomesenchymal chondromyxoid tumor (ECT) is a rare benign neoplasm, often affecting the anterior dorsum of the tongue. To date, approximately 74 cases of lingual ECT have been published. This report describes, for the first time, the morphological and immunohistochemical features of a unique ECT case, which revealed diffuse infiltration by immune cells with a dendritic-like appearance inside the tumor proliferation. The significance of these findings and discussion about the tumor cell-immune cell interactions are presented.

Gingival melanoacanthoma associated with pseudomelanocytic nests: Expanding the clinicopathological spectrum of a recently described oral lesion

Pigmented lesions are commonly found in the oral cavity. These lesions comprise a range of clinicopathological presentations since exogenous substances, physiologic conditions, reactive lesions, manifestations of systemic diseases and benign or malignant neoplasia. Its correct diagnosis requires detailed investigations of the clinical features, as well as careful analysis of the microscopical findings. This article is protected by copyright. All rights reserved.

Abstract B33: Synergistic effect of gefitinib and arsenic trioxide in acute promyelocytic leukemia

Gefitinib and erlotinib are well-known epidermal growth factor receptor (EGFR) inhibitors approved by the Food and Drug Administration for the treatment of non-small cell lung cancer (NSCLC). Interestingly, patients with synchronous NSCLC and acute myeloid leukemia (AML) treated with erlotinib presented regression of both neoplasms, although AML myeloblasts were shown to lack expression of EGFR. In addition, preclinical studies have shown that gefitinib alone or combined with arsenic trioxide (ATO) or all-trans retinoic acid (ATRA) was able to induce differentiation in the EGFR-negative cell lines of acute promyelocytic leukemia (APL), which is a subtype of AML characterized by the t(15;17)/PML/RARA rearrangement. Our previous study demonstrated that EGFR gene expression levels were associated with prognostic outcomes of APL patients treated according to the International Consortium on APL protocol. However, the EGFR levels were not assessed at protein level. Two phase 3 trials reported that ATRA and ATO therapy was associated with excellent outcomes in APL. The two drugs induced the degradation of the PML/RARA oncoprotein through different mechanisms, with ATRA acting through the proteasome pathway, and ATO functioning through the PML-transformation related protein 53 (Trp53) axis. The purpose of this study was to investigate whether gefitinib or erlotinib has synergistic effects with ATO or ATRA in the treatment of APL. To this end, the APL cell lines NB4 and NB4-R2 were treated with gefitinib (C22H24ClFN4O; Selleck Chemicals, #S7786) and erlotinib (C22H23N3O4; Selleck-Chemicals, #S1025) alone or combined with ATO (As2O3; Sigma-Aldrich, #202673). The stock solutions of gefitinib and erlotinib were prepared in DMSO while ATO was dissolved in 1M NaOH solution. Then each drug was diluted with RPMI medium to the desired final concentration. The median effective dose (ED50) for gefitinib was calculated to be 20.97 and 27.06 µM for NB4 and NB4-R2, respectively. ATO was a potent inducer of apoptosis with an ED50 of 2.27 µM for NB4 and 1.73 µM for NB4-R2 cells. ED50 of ATRA (C20H28O2; Sigma-Aldrich, #R2625) was not calculated because ATRA is a potent differentiation inducer but did not induce cell death of APL blasts. Due to the high value of ED50 for NB4 (78.97 µM) and NB4-R2 (111.36 µM) after 24 h of erlotinib treatment, the analysis of this drug was discontinued. The interaction between gefitinib and ATO demonstrated a moderate synergism for NB4 and NB4-R2 with a combination index values of 0.88 and 0.83, respectively. These in vitro results encouraged us to investigate the in vivo effects of gefitinib alone or in combination with ATO and/or ATRA. To this second end, we developed a syngeneic transplant murine model using leukemic cells obtained from transgenic mice hCG-PML/RARA, which develop a form of leukemia that closely recapitulates the human disease. The engraftment of leukemic cells from hCG-PML-RARα transgenic mice transplanted to wild-type littermate recipients was evaluated by morphology and flow cytometry analysis of the peripheral blood (PB), bone marrow (BM), and spleen. Recipient mice were euthanized and evaluated for signs of engraftment 14 (n=3) and 20 (n=3) days after transplantation. Of note, the morphologic analysis revealed >20% of blasts among nucleated cells in the BM samples. The flow cytometric analysis showed the presence of CD11b+ CD117+ cells in PB (median 10.50, range 8.81-12.20), BM (median 18.30, range 17.80-18.80), and spleen (median 16.45, range 16.00-16.90). These results demonstrate that this rapid and robust murine model is useful to assess the efficacy of EGFR inhibitors in APL. Taken together, our preliminary in vitro results suggest that gefitinib and ATO may have potential application for the APL treatment and that this current syngeneic transplant mouse model of APL is suitable to test this hypothesis. Citation Format: Luciana Yamamoto Almeida, Cleide Lucia Araujo Silva, Isabel Weinhauser, Larissa Ananias Cândido, Priscila Santos Scheucher, Camila Cristina Oliveira Menezes Bonaldo, Barbara Amelia Aparecida Santana, Ana Silvia Gouvea Lima Yamada, Eduardo Magalhaes Rego. Synergistic effect of gefitinib and arsenic trioxide in acute promyelocytic leukemia [abstract]. In: Proceedings of the AACR International Conference held in cooperation with the Latin American Cooperative Oncology Group (LACOG) on Translational Cancer Medicine; May 4-6, 2017; Sao Paulo, Brazil. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(1_Suppl):Abstract nr B33.

Dentoalveolar Abscesses Not Associated with Caries or Trauma: A Diagnostic Hallmark of Hypophosphatemic Rickets Initially Misdiagnosed as Hypochondroplasia

Hypophosphatemic rickets is a rare genetic disorder involving the regulation of fibroblast growth factor 23 (FGF23), a phosphaturic agent, clinically showing bowing of the legs, short stature and dentoalveolar abscesses. A 7-year-old boy, with previous hypochondroplasia diagnosis, was referred to our pediatric dentistry clinic presenting short stature, bone deformities and sinus tracts at deciduous teeth apex levels not related with trauma, restorations or dental caries. After deciduous teeth extraction, due to root resorption and mobility, light microscopy exhibited typical hypophosphatemic dentin, and micro-computed tomography revealed tubular clefts and porosities throughout the teeth. Laboratory tests confirmed the HR diagnosis, after which the treatment was initiated.

Mandibular Osteolytic Lesion Associated with Exuberant Hyaline Ring Granuloma Reaction.

Objective: To report an unusual case of oral hyaline ring granuloma (HRG) that caused an extensive osteolytic lesion. Clinical Presentation and Intervention: A 22-year-old female was referred to our hospital with a large expansile cystic lesion in the left mandibular ramus associated with a clinically visible, partially erupted third molar. A diagnosis of paradental cyst was made. After marsupialization of the lesion, histopathological analysis of the surgical specimen showed an unusual exuberant HRG reaction supported by scarce fibrous stroma. Conclusion: This was a case of exuberant HRG reaction that caused extensive bone destruction.