Abstract Adenoid Cystic Carcinoma Research Articles

Abstract LB022: Preclinical anti-tumorigenic evaluation of AXL targeting antibody-drug-conjugate in an adenoid cystic carcinoma cell line xenograft model

Abstract Adenoid cystic carcinoma (ACC) is a rare type of salivary gland cancer. Despite the many advances made in helping understand the disease behavior and characteristics, the prevailing challenge in managing patients with ACC is the lack of clinically approved systemic therapy drugs to successfully treat those with advanced recurrent or metastatic disease. There are multiple promising candidate agents being evaluated preclinically and in early phase clinical trials, yet an effective drug with consistent overall response remains to be identified. AXL is a member of the TAM family of tyrosine kinase receptors, and its overexpression and activation is generally associated with poor prognosis and chemoresistance in many cancer types. Previous reports show AXL is significantly upregulated in a subset of ACC tumors. Here, we evaluate the tumor growth inhibition effects of a newly developed antibody-drug-conjugate targeting AXL (ADCT-601) in a xenograft ACC cell line model. MDA-ACC-01 cells express high levels of cell surface AXL as confirmed by biochemical analysis. The tumor growth inhibition of MDA-ACC-01 cell xenograft was tested in a single-dose drug administration study. Immunodeficient mice bearing ACC tumors were either injected with vehicle (n=7) or with ADCT-601 at 0.5 (n=9) or 1.0 mg/kg (n=7). ADCT-601 treatment with either 0.5 mg/kg or 1.0 mg/kg resulted in complete response (CR) for all tumor implants. To reaffirm the drug’s efficacy, we challenged the vehicle-treated tumor, prior to exceeding the tumor volume endpoint, with a single-dose of ADCT-601 at 1.0 mg/kg. Strikingly, by day 6 post-treatment, tumor volume began to shrink and eventually resulted in CR except in all but one case. These results demonstrate ADCT-601 is an effective drug with significant anti-tumor activity in our preclinical models and is worthy of additional investigation to determine its translational potential. Citation Format: Joseph O. Humtsoe, Anita Pothukuchi, Hyunseok Kang, Patrick Ha. Preclinical anti-tumorigenic evaluation of AXL targeting antibody-drug-conjugate in an adenoid cystic carcinoma cell line xenograft model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB022.

Abstract 7550: KB-0742, an oral highly selective CDK9 inhibitor, demonstrates preclinical activity in transcription factor fusion driven adenoid cystic carcinoma patient-derived models

Abstract Adenoid Cystic Carcinoma (ACC) is an aggressive rare type of cancer of the secretory glands with no approved targeted therapy and high unmet clinical need. Deregulated transcription driven by MYB-NFIB or MYBL1-NFIB transcription factor (TF) fusions are a hallmark of ACC pathogenesis. More aggressive disease and resistance to therapy has been associated with co-mutation in NOTCH. Although direct targeting of oncogenic TF fusions has remained challenging, targeting of their activity via transcriptional cofactors has emerged as an attractive and clinically actionable strategy. Cyclin-dependent kinase 9 (CDK9) is a key potentiator of TF activity via its ability to act both as an upstream regulator of TF expression and a downstream cofactor. KB-0742 is a potent, selective, and orally bioavailable inhibitor of CDK9 with a long plasma half-life. KB-0742 is being studied in an ongoing Phase 1/2 study (NCT04718675) in advanced solid tumors including ACC. KB-0742 has demonstrated on-mechanism, single agent anti-tumor activity and a manageable safety profile in heavily pre-treated patients (0-11 prior lines of therapy) with transcriptionally addicted solid tumors. Here we present the preclinical rationale for targeting of oncogenic fusion TF activity in ACC. XenoSTART Patient-Derived Xenograft (XPDX) models were established from viable human tumor tissue for in vivo and ex vivo testing. Cell viability was assessed by CellTiter GLO reagent and phase imaging. Changes in MYB-fusion transcripts were assessed by RNA-Seq. Tumor Fragments (~70 mg) from ACCx5M1, ACCx6, ACCx9, ACCx11 models were implanted into athymic nude mice. Animals were treated with either vehicle (normal saline) or 60 mg/kg KB-0742 on a Q3D/week until tumors reached 2500 mm3 or up to 60 days post start of treatment. In a retrospective analysis using real world data, ACC has a low incidence of genomic instability and high rates of MYB fusions detectable by RNA-seq, making immunotherapy challenging but creating an opportunity for targeting MYB transcription. In primary MYB-fusion positive and NOTCH co-mutated patient-derived spheroid models, KB-0742 treatment induced strong antiproliferative activity and cytotoxicity. Importantly, KB-0742 demonstrated stronger cytotoxic effects when compared to historical control agents. In XPDXs, CDK9 inhibition with KB-0742 resulted in antiproliferative activity and stronger tumor growth inhibition in MYB-fusion positive and NOTCH co-mutated tumor models compared to MYB-fusion positive only models.These data demonstrate KB-0742 is effective in preclinical models of ACC suggesting KB-0742 may be a promising therapeutic option for ACC patients. KB-0742 is currently being evaluated in a phase 1/2 dose-escalation and cohort expansion trial in patients with ACC and other transcriptionally addicted tumors (NCT04718675). Citation Format: Michael R. McKeown, Luis A. Carvajal, Tressa R. Hood, Nicole S. Burr, Jeffrey Kaufman, Adam Boynton, Kameron Mori, Tessa DesRochers, Michael Wick, Charles Y. Lin, Jorge F. DiMartino. KB-0742, an oral highly selective CDK9 inhibitor, demonstrates preclinical activity in transcription factor fusion driven adenoid cystic carcinoma patient-derived models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7550.

Abstract 4897: PRT543, a methyl transferase inhibitor, has potent anti-tumor activity against adenoid cystic carcinoma of salivary glands

Abstract Adenoid Cystic Carcinoma (ACC) is a rare but aggressive malignancy of salivary gland, associated with protracted clinical course and fatal outcome. Treatment modalities are restricted to surgery and/or adjuvant radiotherapy and patients develop recurrence and distant metastasis over time. The absence of effective systematic therapy makes it incurable in advanced stage. ACC display an overall low mutation frequency, therefore very few actionable genetic alterations critical to the ACC development have been recognized. MYB fusion/overexpression is the most frequently found genetic alteration in ACC and is present in ~70% patients. This is followed by activating NOTCH mutations, reported in ~20% patients. Despite the presence of few targetable genetic alterations, recent studies revealed substantial transcriptomic heterogeneity amongst ACC tumors suggesting the role of epigenetic alterations in ACC oncogenesis. Symmetric dimethylation is an important epigenetic mechanism that regulates mRNA splicing, transcription, translation, cell cycle and oncogenic signaling pathways. Protein Arginine Methyl Transferase 5 (PRMT5) is a predominant enzyme for symmetric dimethylation among a family of 9 methyl transferases. In was suggested that PRMT5 plays a role in regulating tumor progression via modulation of MYC signaling, cancer stemness, and a wide array of additional cellular and transcriptional pro-oncogenic processes. While inhibition of PRMTs showed anti-oncogenic response in several preclinical tumor models and a subset of patients with advanced solid malignancies (including ACC), preclinical studies investigating the effect of PRMT5 blockade in ACC remain inadequate. In part, due to the scarcity of ACC specimens and limited availability of the experimental models. PRT543 is a selective and potent small molecule PRMT5 inhibitor that specifically targets PRMT5 among 37 methyl transferases. In the present study, we have investigated the effect this novel agent using a unique collection of ACC cell lines, organoids, and patient derived xenograft mouse models. To our knowledge, this is the first study investigating the therapeutic effect of PRT543 in several preclinical models of ACC. Specifically, we found that PRT543 has potent antitumor activity in in-vitro and in-vivo models with MYB expression and activating NOTCH mutations. Further, based on these observations, we have sequenced a collection of 50 ACC tumor samples to identify the subset of patients who may potentially benefit from PRT543 treatment based on their underlying genetic signatures. This study provides evidence underscoring the role of PRMT5 signaling in ACC and supports the clinical development of PRMT5 inhibitors for this indication. Citation Format: Vasudha Mishra, Alka Singh, Xiangying Chen, Michael Korzinkin, Claudia Wing, Viktoria Sarkisova, Alexandra Ozerova, Oksana Glushchenko, Venkat Thodima, Koichi Ito, Peggy Scherle, Mark Lingen, Rifat Hasina, Alexander Pearson, Ari Rosenberg, Alex Zhavoronkov, Bruce Ruggeri, Nishant Agrawal, Evgeny Izumchenko. PRT543, a methyl transferase inhibitor, has potent anti-tumor activity against adenoid cystic carcinoma of salivary glands. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4897.

Abstract 2098: Molecular based blood screening assay for metastatic adenoid cystic carcinoma

Abstract Adenoid cystic carcinoma (ACC) is a rare, yet highly lethal, tumor that originates in the excretory glands of the head and neck. It is a locally aggressive disease, with more than half of patients presenting with perineural invasion and/or bone erosion. The current standard of care consists of surgical excision followed by radiation. Many healthy patients are left with positive margins after surgery and receive systemic therapy in addition to adjuvant radiation without evidence showing added benefit for that approach. Despite extensive surgery, long-term survival rates remain low due to a high incidence of locoregional disease progression and metastatic disease to the lung, liver, brain, or bones, sometimes several years after definitive treatment. Extensive genome analysis of ACC has uncovered a high mutation rate of the proto-oncogene MYB, typically as a genomic translocation resulting in an MYB fusion event with one of the following gene loci: nuclear factor I/B (NFIB), transforming growth factor beta 3 (TGFBR3) or RAD51B. The translocation approximates an enhancer to the MYB regulatory element which can be transactivated by the MYB fusion product, thus leading to the overexpression of MYB via a positive feedback mechanism. Currently, detection of systemic disease relies on diagnostic imaging, which can be imprecise, costly and time-consuming. Years of routine imaging is very impractical, attrition rates are high, and patients often present years later with symptomatic metastatic disease. A rapid and sensitive molecular-based blood screening tool would allow for continuous monitoring and earlier detection of metastatic ACC, ideally improving survival outcomes for these patients. In this study, we hypothesized that the dysregulation in MYB, and the reliance of ACC cells on MYB for survival and progression could be harnessed to develop a molecular screening tool to monitor for metastatic disease of ACC. We developed a blood-based PCR screening probes for metastatic disease in patients with a history of ACC. By analyzing blood samples from four cohorts: healthy individuals (no history of cancer) (n=6), patients with a history of ACC but with no evidence of disease for longer than 3yrs (NED) (n=16), patients with newly diagnosed local disease (n=8), and patients with confirmed metastatic disease (n=7), we demonstrate that our assay was able to detect significantly elevated levels of aberrant MYB expression in all blood specimens from our metastatic disease cohort (p < 0.01). Additionally, our probes were able to detect aberrant levels of MYB in the blood of a patient 11 months before imaging techniques identified metastatic lung lesions. These findings indicate that we can harness a specific ACC genetic trait to develop a sensitive, rapid, and inexpensive molecular screening assay from blood to detect metastatic ACC. We continue to expand and validate these findings by screening existing and new ACC patients every 6 months. Citation Format: Acadia H. Moeyersoms, Ryan A. Gallo, Zoukaa B. Sargi, Jason M. Leibowitz, Andrew J. Rong, David T. Tse, Daniel Pelaez. Molecular based blood screening assay for metastatic adenoid cystic carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2098.

The anti-tumor effect of proteasome inhibitor MG132 for human adenoid cystic carcinoma: correlate with the emerging role of Nrf2/Keap1 signaling pathway.

BackgroundAdenoid cystic carcinoma (ACC) is one of the most common malignant salivary gland tumors. Moreover, the unique biological characteristics and complex structures of ACC contribute to its poor survival rates. Recently, proteasome inhibitors have been shown to elicit satisfactory therapeutic effects in the treatment of certain solid tumors, but few studies have been implemented to investigate the effects of proteasome inhibitor therapy for ACC.MethodsIn this present study, cell counting kit-8 assay and flow cytometry assay were performed to examine the effects of proteasome inhibitor (MG132) on cell viability and apoptosis. We applied western blot and immunofluorescence staining to explore the expression of the Nrf2/Keap1 signaling pathway and P62, additionally Nrf2 inhibitor (ML385) was utilized to evaluate the role of Nrf2/Keap1 signaling pathway in MG132-induced cell apoptosis.ResultsOur data indicated that MG132 significantly suppressed the growth of ACC-83 cells(MG132 10µM P = 0.0046; 40µM P = 0.0033; 70µM P = 0.0007 versus control) and induced apoptosis (MG132 10µM P = 0.0458; 40µM P = 0.0018; 70µM P = 0.0087 versus control). The application of MG132 induced the up-regulation of Nrf2/Keap1 signaling pathway. Furthermore, inhibition of Nrf2 attenuated the therapeutic effects of MG132 for ACC (both ML385 + MG132 10µM P = 0.0013; 40µM P = 0.0057; 70µM P = 0.0003 versus MG132). P < 0.05 was considered statistically significant.ConclusionsOur results revealed that proteasome inhibitors MG132 could inhibit the cell viability and induce the apoptosis of ACC through Nrf2/Keap1 signaling pathway.

Development and Characterization of MYB-NFIB Fusion Expression in Adenoid Cystic Carcinoma.

Simple SummaryChromosomal t(6;9) translocation is commonly found in adenoid cystic carcinoma (ACC) of the salivary gland. This genetic rearrangement results in the fusion of MYB and NFIB genes. Despite the frequent occurrence of t(6;9) translocation and MYB-NFIB gene fusion, the nature of chimeric MYB-NFIB proteins and their potential relevance in the development and behavior of ACC remains poorly understood. The lack of validated ACC cell lines, harboring the t(6;9) translocation with defined MYB-NFIB fusion protein, has restricted fusion-specific functional studies. Hence, we sought to characterize and establish in vitro and in vivo models of a MYB-NFIB fusion protein expressing system in ACC. Defining the nature and functional aspect of MYB-NFIB fusion proteins may not only improve our understanding of the disease but also contribute to the identification of molecular targets that are druggable and can be developed for future therapeutic purpose.Adenoid cystic carcinoma (ACC) is the second most common cancer type arising from the salivary gland. The frequent occurrence of chromosome t(6;9) translocation leading to the fusion of MYB and NFIB transcription factor genes is considered a genetic hallmark of ACC. This inter-chromosomal rearrangement may encode multiple variants of functional MYB-NFIB fusion in ACC. However, the lack of an ACC model that harbors the t(6;9) translocation has limited studies on defining the potential function and implication of chimeric MYB-NFIB protein in ACC. This report aims to establish a MYB-NFIB fusion protein expressing system in ACC cells for in vitro and in vivo studies. RNA-seq data from MYB-NFIB translocation positive ACC patients’ tumors and MYB-NFIB fusion transcript in ACC patient-derived xenografts (ACCX) was analyzed to identify MYB breakpoints and their frequency of occurrence. Based on the MYB breakpoint identified, variants of MYB-NFIB fusion expression system were developed in a MYB-NFIB deficient ACC cell lines. Analysis confirmed MYB-NFIB fusion protein expression in ACC cells and ACCXs. Furthermore, recombinant MYB-NFIB fusion displayed sustained protein stability and impacted transcriptional activities of interferon-associated genes set as compared to a wild type MYB. In vivo tumor formation analysis indicated the capacity of MYB-NFIB fusion cells to grow as implanted tumors, although there were no fusion-mediated growth advantages. This expression system may be useful not only in studies to determine the functional aspects of MYB-NFIB fusion but also in evaluating effective drug response in vitro and in vivo settings.

Primary cutaneous adenoid cystic carcinoma - An onerous task for clinicians and pathologists.

Adenoid cystic carcinoma (ACC) is an uncommon malignant neoplasm usually confined to the salivary glands, lungs, and breasts. Primary cutaneous adenoid cystic carcinoma (PCACC) is an extremely rare entity with solitary cases reported at sites away from the scalp and chest. Hence, one must follow the multidisciplinary approach to exclude any primary ACC elsewhere in the body. We report a rare case of PCACC arising from the skin of the left lower limb in a 55-year-old woman with a history of recurrent swelling, clinically diagnosed as a metastatic tumor.

A rare case of advanced sinonasal adenoid cystic carcinoma with intracranial and intradural extension

Adenoid cystic carcinoma (ACC) is a rare cancer of the head and neck that primarily occurs in the salivary glands. Sino-nasal ACC (SNACC) is a much rarer entity; this paper presents an exceedingly rare case of SNACC with both intracranial and intradural extension which was ultimately treated with palliative radiotherapy due to its extensive invasion. In addition to this, a review of the literature has been performed to delineate specific learning points for the management of intracranial SNACC.

Diagnosis of metastatic adenoid cystic carcinoma of the breast on pleural fluid cytology in a 60‐year‐old male

Adenoid cystic carcinoma (AdCC) is a rare triple-negative breast cancer with a favorable prognosis, although cases of distant metastases have been reported. Less than 10 cases of AdCC of the breast in males have been reported. We report a unique presentation of pleural fluid metastasis diagnosed by cytologic evaluation of pleural fluid in a 60-year-old male patient with AdCC of the breast. Careful surveillance and cytologic evaluation of effusion specimens can detect metastases with the aid of cellblock preparations and immunohistochemical stains.

ADENOID CYSTIC CARCINOMA IN THE PALATE: NUMBNESS AS INITIAL OROFACIAL MANIFESTATION

Adenoid cystic carcinoma (ACC) is a malignant epithelial tumor of the salivary glands that commonly affects the minor salivary glands, and the palate is the most recurrent site. Treatment is challenging because this tumor tends to recur with distant metastases and poor prognosis. A 50-year-old woman complained of numbness in the upper left hemimaxilla, extended to the labial region, nose wing, and nasolabial sulcus, with clinical intra-oral alterations similar to an endodontic fistula tooth 25 palatal mucosa and discrete periapical rarefaction on radiologic evaluation. Endodontic treatment was provided with laser therapy administered for persistent numbness. After 3 months a palate volume increase and small ulcerated region were noted encompassing the region of teeth 24 to 27. The panoramic and tomographic examination was performed showing extensive bone destruction, and the patient underwent a biopsy followed by microscopic and immunohistochemistry evaluation and diagnosis as ACC. The patient was forwarded to a head and neck surgeon.

Adenoid cystic carcinoma of the breast

Adenoid cystic carcinoma (ACC) is a rare histological form of the breast cancers. Due to the rarity of this type of carcinoma, the therapeutic management strategy still controversial. A retrospective study reporting data concerning five patients with breast ACC diagnosed between 1993 and 2017. Cases were reviewed for age at diagnosis, clinical, radiological and histological tumour presentation, type of treatment and treatment outcomes. Out of a total of 3066 breast cancer patients, 5 patients had breast ACC (0.1%). The median age at diagnosis was 46 years (range 26-57 years). A palpable mass was the common presenting symptom in all cases. No patient had clinical evidence of regional lymph node metastases and staging investigations showed no evidence of metastatic disease. All patients underwent primary surgery with ipsilateral axillary lymph node dissection in 3 cases. Adjuvant chemotherapy was performed in two patients and postoperative radiotherapy in all cases. Tamoxifen-based hormonal therapy was administered in an only patient who had positive hormonal receptors. After a median follow-up of 107 months, the overall mean survival was 106.8 months and the average disease-free survival was 97.8 months. Breast ACC has a low propensity for local recurrence after excision despite triple negative nature. Since the frequency of axillary lymph node metastases is very low, we suggest that lymphadenectomy is to be avoided in this type of tumour. Adjuvant radiotherapy remains a standard treatment after conservative surgery.

TWO RARE CASES OF ADENOID CYSTIC CARCINOMA OF THE PAROTID GLAND PRESENTING AS A BONE LESION

Adenoid cystic carcinoma (ACC) is a relatively rare salivary gland malignancy, exhibiting a lethal clinical course often several years after initial diagnosis. It is rarely found outside major or minor salivary glands especially as a bone lesion. Here, 2 rare clinical conditions of ACC arising from the parotid gland and spreading into the mandible are presented. A 50-year-old woman and 49-year-old man presented with pain and paresthesia in the left face. A swelling was observed and computed tomography detected an osteolytic lesion with irregular margins in the mandible. Clinical diagnosis included osteomyelitis and sarcoma. Tumors presented as solid masses with few ductiform structures and exhibited perineurial invasion in the inferior alveolar nerve and high-grade transformation. Challenges in the diagnosis of ACC highlight the need for meticulous clinical management in an effort to allow for early detection of the primary tumor and initiation of the appropriate therapy.

INTRAOSSEOUS ADENOID CYSTIC CARCINOMA OF MAXILLA: AN UNUSUAL PRESENTATION

Adenoid cystic carcinoma (ACC) is a relatively rare tumor of epithelial cell origin. Palatal minor salivary glands are the most commonly affected locations followed by parotid, and submandibular glands. Bone lesions are rare. The mandible is more commonly involved than the maxilla. A 36-year-old woman presented with a painless swelling in the right maxilla, resulting in a marked facial asymmetry. Intraorally, a swelling affecting gingiva and crossing the midline of the hard palate was observed. Panoramic radiograph showed an ill-defined radiolucency, involving the right maxilla at the level of alveolar ridge and opacifying the maxillary sinus. Microscopy revealed basophilic cribriform islands and solid sheets of neoplastic cells invading bone trabeculae. Most of the tumoral cells presented myoepithelial characteristics and few true luminal/epithelial. Immunohistochemistry showed positivity for AE1/AE3, CK5, CK7, CK14, CK18, CK19, CK20, p63, α–smooth muscle actin, calponin, CD117, S-100, and Ki-67. ACC in the maxilla are rare but should be considered as differential diagnosis.

Adenoid Cystic Carcinoma of the Cervix: Case Report

Adenoid cystic carcinoma (ACC) is usually an epithelial neoplasm of the salivary glands but can also occur in the lacrimal glands and the mucous glands of the respiratory tract, breasts and skin. Very rarely, it may affect the uterine cervix. We report here a case of a woman with postmenopausal bleeding for 7 months, who on physical examination presented with a vegetative and friable tumor lesion in the uterine cervix, measuring about 5 cm in diameter. The abdominal and pelvic computed tomography scans showed a hypodense and heterogeneous mass in the cervix and uterine isthmus. Histopathological examination and immunohistochemical assays confirmed the diagnosis of ACC. The different pathological aspects, therapeutic options and prognostic factors of ACC are discussed.

Adenoid Cystic Carcinoma of Buccal Mucosa: A Rare Presentation

Adenoid Cystic Carcinoma (ACC) is an unusual slow growing, aggressive neoplasm of salivary gland, constituting less than 1% of all head and neck malignancies. It commonly affects adults in the fourth to sixth decades and typically involves minor salivary glands of palate followed by parotid, and submandibular glands. We present here a case of a 16-year-old female diagnosed with ACC involving the buccal mucosa and abutting the distal end of stenson’s duct along with the surgical management and follow up.

Adenoid cystic carcinoma of the nasopharynx: a case report and a discussion about prognostic factors and the role of local treatments.

Adenoid cystic carcinoma (ACC) is a rare epithelioid malignancy. It occurs most frequently in the salivary glands, while its localization in the nasopharynx is rare and few cases have been reported in the literature. We report the case of a 32-year-old woman presenting with ACC of the nasopharynx who was treated with surgery and adjuvant intensity-modulated radiation therapy (IMRT, total dose: 68 Gy) and concomitant chemotherapy (cisplatin 100 mg/m² on the first and 21st days of IMRT). During irradiation, the patient developed G1 dermatitis and G2 mucositis (RTOG). Clinical and instrumental reevaluation 17 months after the end of radiotherapy did not show any signs of relapse, and she did not show any sign of local mild-severe toxicity. Adjuvant radiotherapy after standard complete surgical resection seems to be effective and well tolerated and should be strongly considered in the multidisciplinary approach to this infrequent carcinoma.

A case of sublingual adenoid cystic carcinoma involving the mandible presenting as a “skip lesion”

Adenoid cystic carcinoma (ACC) is a slowly growing malignant neoplasm with a propensity for perineural invasion. Microscopic invasion of ACC often prevents its detection on computed tomography (CT) or magnetic resonance imaging (MRI). We herein report a rare case of sublingual ACC presenting as a "skip lesion" that rapidly infiltrated the mandible after tumor resection. A 64-year-old man presented to Okayama University Hospital with an 18-month history of swelling in the right floor of the mouth. Clinical examination displayed an ulcerated swollen mass in that region. An enhanced mass was detected in the right sublingual space on CT and MRI. Bone surface erosion was observed at the inferior border of the mandible, but continuity with the sublingual mass or mass around that lesion was not detected by imaging. Sublingual tumor resection and selective neck dissection were performed by the pull-through method. Histopathologically, the surgical margins were free of cancer cells, and the tumor was diagnosed as ACC. Continuity with the sublingual mass and mandibular bone was not detected intraoperatively. However, marked bone resorption was detected in the anterior mandible 3months after the operation. Biopsy was performed, and the findings indicated the same histological type of sublingual ACC. This case suggests that a malignant tumor close to the jaw bone requires the clinician to consider the possibility of bone invasion and to observe a wide region surrounding the tumor using imaging examination.

A case of palatal adenoid cystic carcinoma with late recurrence.

Adenoid cystic carcinoma (ACC) is a slow-growing, indolent cancer which normally develops in the head and neck salivary glands, but occasionally in the uterus.1 It can present with swelling, pain, and paraesthesia, as well as other symptoms such as epistaxis, nasal obstruction, depending on the location of the tumour.2 It accounts for 1% of the malignant tumours of the head and neck region.3 Classical management involves surgery and subsequent radiotherapy.4 The researchers describe a case of ACC of the minor salivary glands of the palate and nasopharynx that recurred 8 years following completion of treatment. A 57-year-old female presented to her GP with a 3-month history of left-sided catarrh and epistaxis from her left nostril. Clinical examination was unremarkable and the patient was initially diagnosed with sinusitis. However, the symptoms did not resolve following treatment for sinusitis. On further examination, her dentist noted left palatal swelling and referred her to the maxillofacial clinic by which time she had been suffering from these symptoms for 18 months. In hindsight, her epistaxis might have been a warning sign, and on reflection, the GP highlighted the need to take new epistaxis seriously. Clinical examination by the maxillofacial team revealed diffuse palatal swelling of the hard palate. Subsequent magnetic resonance imaging (MRI) showed a palatal tumour extending into the floor of the left nasal cavity and projecting into the left maxillary antrum through the medial wall. Biopsy of the palate showed an invasive tumour indicative of an ACC of minor salivary glands in the palate. Staging was T4N0M0. She underwent a …

Adenoid Cystic Carcinoma of Para-nasal Sinuses

Adenoid cystic carcinoma (ACC) is an uncommon tumour usually arise in the head and neck region mainly in the salivary gland and rare in the nose and para-nasal sinuses (PNS). We report a rare case of 35-year-old male with ACC of PNS who presented with nasal obstruction and nasal discharge. The CT PNS and orbits show illdefined minimally enhancing soft tissue density lesion extending into buccinators fossa, PNS, nasal cavity with adjacent bony destruction. Surgical incision was done and biopsy revealed ACC. Radiotherapy was given and regular follow-up done. The ACC of sinonasal cavities has poor prognosis, high recurrence due to peri-neural invasion. Multimodality treatment is the mainstay of ACC

Definitive radiotherapy for inoperable adenoid cystic carcinoma of the trachea: A rare case report.

Adenoid cystic carcinoma (ACC) of the trachea is rare; it represents 1% of all respiratory tract cancers. It is generally considered as a slow-growing, with prolonged clinical course. Most patients present with dyspnea, and the symptoms often mimic those of asthma or chronic bronchitis. Surgical resection is the mainstay of treatment often combined to radiotherapy because of close surgical margins. When surgery is not possible, most tumors respond to radiotherapy alone which often results in long periods of remission. There is no consensus on the best treatment for locally advanced inoperable ACC of trachea. This case report describes a 51-year-old woman unresectable ACC of trachea due to comorbid conditions, successfully managed by intensity modulated radiotherapy. At 8 months follow-up, the patient is healthy and asymptomatic.