Adenoid cystic carcinoma of the lacrimal gland: MYB gene activation, genomic imbalances, and clinical characteristics

Tumor immune microenvironment in adenoid cystic carcinoma of the lacrimal gland: relationship with histopathology and prognosis

PURPOSE

To quantitatively investigate the pathological subtypes of lacrimal gland adenoid cystic carcinoma (LGACCs), the tumor immune microenvironment in each pathological subtype, and the relation to survival.

METHODS

In this retrospective study, the tumor subtype was determined by H&E staining. Multiplex immunochemistry was performed to define specific immune cells. The tumor immune microenvironment (TIME) was sketched by sequential image scanning and reconstructed by a cytometry platform.

RESULTS

Eighteen patients with adequate paraffin blocks diagnosed with LGACC from 2012 to 2021 were included in this study. Thirteen patients out of the eighteen patients (72.2%)showed a mixture of different pathological subtypes. Each pathological subtype took different percentages on different tumors. The cribriform was the most common subtype, taking an overall percentage of 39%. The rest of the pathological subtypes were tubular (19%), basaloid (17%), cribriform and tubular mixture (C + T) 14%. The sclerosing and comedocarcinomic subtypes were the least seen in LGACC, taking a percentage of 11% altogether. Patients with cribriform dominant component had better overall survival than the non-cribriform dominant patients. Patients with basaloid dominant component had worse clinical outcomes than the non-basaloid dominant ones. The TIME showed high immunogenicity in the tumor margin but declined in the tumor areas. Pathological subtypes rather than individual differences determined the TIME phenotype. The cribriform subtype possessed more immune cell infiltration than other pathological subtypes.

CONCLUSIONS

LGACC is composed of multiple pathological subtypes. Each pathological subtype takes different percentages on different tumors, which is related to the prognosis. TIME pattern in LGACC varies among different pathological subtypes, which could indicate novel strategies in immunotherapy.

Clinical and histopathological factors for recurrence and metastasis in lacrimal gland adenoid cystic carcinoma in Chinese patients

PURPOSE

To investigate the association of metabolism-related proteins and clinicopathological features with poor prognosis in lacrimal gland adenoid cystic carcinoma (LGACC).

METHODS

Clinicopathological data for 39 Chinese patients with LGACC enrolled were retrospectively analysed. Disease progression included death, recurrence, further nodal metastasis, and distant metastasis. Expression of ASCT2 and GLS1 were evaluated by immunohistochemistry. Kaplan-Meier survival curves and Cox proportional hazards regression models were used for risk factor analyses.

RESULTS

At the end of follow-up, 14 patients (35.9%) developed local recurrence, 13 patients (33.3%) developed distant metastasis, 3 patients (7.7%) developed lymph node metastasis, and 9 patients (23.1%) died. Among the 13 patients who developed distant metastasis, lung metastasis was observed in 8 patients (61.5%), the brain in 8 patients (61.5%), and bone in 1 patient (7.7%). ASCT2 was expressed in 16 (57.14%) cases, while GLS1 had high expression in 19 (67.9%) cases. Advanced T category (≥T3), bone erosion, basaloid subtype, and ASCT2 (-) were associated with disease progression. Basaloid subtype was an independent risk factor for local recurrence (P = 0.028; HR, 12.12; 95% CI, 1.3-111.5). ASCT2(-) was an independent risk factor for distant metastasis (P = 0.016; HR, 14.46; 95% CI, 1.6-127.5) and was associated with basaloid subtype (P = 0.019).

CONCLUSIONS

For LGACC, ≥T3 category, basaloid subtype, and bone erosion were high-risk predictors. ASCT2(-) was an independent risk factor for distant metastasis, which suggested that it could be a potential biomarker for LGACC.

MYB immunohistochemistry as a predictor of MYB::NFIB fusion in the diagnosis of adenoid cystic carcinoma of the head and neck

OBJECTIVES

Diagnosing adenoid cystic carcinoma (AdCC) is challenging due to histopathological variability and similarities with other tumors. In AdCC pathogenesis, the cellular myeloblastosis gene (c-MYB) often exhibits a MYB::NFIB fusion from a reciprocal translocation. This study aimed to assess the predictive accuracy of MYB immunohistochemistry for detecting this translocation compared to fluorescence in situ hybridization (FISH).

STUDY DESIGN

This study included 110 AdCC patients (1999-2017) from two Dutch head and neck centers using tissue microarrays and full slides. Median MYB expression levels by immunohistochemistry were compared based on translocation status by FISH, and differences within clinicopathological parameters were examined. An immunohistochemical cut-off was established to estimate the translocation.

RESULTS

MYB immunohistochemistry was available in 90/110 patients, with a median expression of 27%. FISH was interpretable in 79/108 tumors, identifying MYB::NFIB fusion in 44 (56%). Among 62 patients with both MYB expression and translocation data, the fusion was present in 38 (61%). These tumors had higher MYB expression (30%) than nontranslocated tumors (6%); P = .02. A 60% MYB expression cut-off yielded 100% specificity for detecting the translocation but had no prognostic value.

CONCLUSIONS

Although MYB protein expression alone lacks diagnostic precision, protein expression >60% predicted the MYB::NFIB fusion in all tumors.

Prognostic Impact of Notch1 Intracellular Domain, P63, and c-MYC in Lacrimal Gland Adenoid Cystic Carcinoma

Purpose

We assessed whether NICD1 expression, c-MYC expression, and P63 expression by immunohistochemistry (IHC) correlate with prognosis and high-risk clinicopathological features in lacrimal gland adenoid cystic carcinoma (ACC).

Methods

Records of patients with lacrimal gland ACC who underwent surgery between 1998 to 2018 were reviewed. Clinicopathologic and treatment data were collected. Tumor tissues were subjected to light microscopy and IHC.

Results

Of 43 patients treated during the study period, 21 had archived tumor tissue available and were included. The median age at diagnosis was 47 years, and 13 patients (62%) were male. Thirteen patients (62%) had T2 disease, and none had nodal or distant metastasis at diagnosis. Tumors were positive for NICD1 expression in eight cases (38%), c-MYC expression in eight (38%), and P63 expression in 11 (52%). Positive NICD1 expression was associated with predominantly solid (vs. cribriform/tubular) pattern (P < 0.001), treatment with orbital exenteration (vs. eye-sparing surgery) (P = 0.008), local recurrence (P = 0.047), and death (P = 0.012). Negative P63 expression was associated with predominantly solid pattern (P = 0.001), local recurrence (P = 0.012), distant metastasis (P = 0.001), and death (P = 0.035). A higher percentage of tumor cells staining for c-MYC was associated with presence of perineural invasion (P = 0.036). Positive NICD1 expression was associated with worse disease-free survival (hazard ratio, 6.27; 95% CI, 1.29-30.46), whereas positive P63 expression was associated with better disease-free survival (hazard ratio, 0.03; 95% CI, 0.0002-0.26).

Conclusions

IHC for NICD1 and P63 should be considered in lacrimal gland ACC because of their prognostic value and potential as treatment targets.

Molecular Analysis of Salivary and Lacrimal Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) of head and neck origin is associated with slow but relentless progression and systemic metastasis, resulting in poor long-term survival rates. ACC does not respond to conventional chemotherapy. Determination of molecular drivers may provide a rational basis for personalized therapy. Herein, we investigate the clinical and detailed molecular genomic features of a cohort of patients treated in Ireland and correlate the site of origin, molecular features, and outcomes. Clinical and genomic landscapes of all patients diagnosed with ACC over a twenty-year period (2002-2022) in a single unit in Ireland were examined and analyzed using fluorescence in situ hybridization, DNA sequencing, and bioinformatic analysis. Fourteen patients were included for analysis. Eleven patients had primary salivary gland ACC and three primary lacrimal gland ACC; 76.9% of the analyzed tumors displayed evidence of NFIB-MYB rearrangement at the 6q23.3 locus; 35% had mutations in NOTCH pathway genes; 7% of patients had a NOTCH1 mutation, 14.3% NOTCH2 mutation, and 14.3% NOTCH3 mutation. The presence of epigenetic modifications in ACC patients significantly correlated with worse overall survival. Our study identifies genetic mutations and signaling pathways that drive ACC pathogenesis, representing potential molecular and therapeutic targets.

[Interdisciplinary Management of Orbital Diseases]

Diagnosis and therapy of orbital diseases is an interdisciplinary challenge, in which i.e. otorhinolaryngologists, ophthalmologists, radiologists, radiation therapists, maxillo-facial surgeons, endocrinologists, and pediatricians are involved. This review article describes frequent diseases which both, otolaryngologists and ophthalmologists are concerned with in interdisciplinary settings. In particular the inflammatory diseases of the orbit including orbital complications, autoimmunological diseases of the orbit including Grave´s orbitopathy, and primary and secondary tumors of the orbit are discussed. Beside describing the clinical characteristics and diagnostic steps the article focusses on the interdisciplinary therapy. The review is completed by the presentation of most important surgical approaches to the orbit, their indications and possible complications. The authors tried to highlight the relevant facts despite the shortness of the text.

Adenoid Cystic Carcinoma of the Lacrimal Gland

Purpose

To explore the various aspects of adenoid cystic carcinoma of the lacrimal gland (LACC), including its clinical features, presentations, genetic factors, as well as current and potential future treatment options.

Methods

A thorough exploration of the literature was conducted by extensively searching the PubMed database. A total of 68 articles with a primary focus on adenoid cystic carcinoma were selected.

Results

LACC is the most frequent malignant epithelial tumor of the lacrimal gland. It is characterized by the symptoms such as pain, progressive swelling of the eye, double vision, and bulging of the eye. Although LACC is a rare tumor, early detection and appropriate treatment are crucial due to its aggressive nature which includes high recurrence rate and a significant risk of mortality. The primary treatment options for LACC involve a wide range of surgical procedures, including orbitotomy, exenteration, and cranio-orbital resection. Neoadjuvant intra-arterial chemotherapy represents the paradigm shift in the treatment of LACC enhancing patient survival when compared to conventional treatments.

Conclusion

The existing literature emphasizes the importance of identifying prognostic factors that can guide treatment decisions and enhance the outcomes for patients with LACC.

Molecular characterisation of tumours of the lacrimal apparatus

AIMS

Malignant tumours of the lacrimal apparatus are rare and frequently show a poor prognosis, with no clear therapeutic standards. Characterisation of the genetic landscape of these rare tumours is sparse, and therefore therapeutics generally follow those of their common salivary gland counterparts. To further clarify the pathophysiology and discover potential therapeutic targets, we investigated the genetic landscape of eight tumours of the lacrimal apparatus.

METHODS AND RESULTS

DNA and RNA sequencing were performed to identify genetic mutations and gene fusions. Immunohistochemistry, fluorescence in-situ hybridisation and reverse transcription-polymerase chain reaction followed by Sanger sequencing were performed to confirm the identified molecular alterations. Genetic alterations were detected in six tumours. Among five adenoid cystic carcinomas (ACC), four had confirmed alterations of MYB or MYBL1 genes, including a MYB::NFIB fusion, a MYBL1::NFIB fusion, a MYB amplification and a novel NFIB::THSD7B fusion. Mutations in genes encoding epigenetic modifiers, as well as NOTCH1, FGFR2 and ATM mutations, were also identified in ACCs. A carcinoma ex pleomorphic adenoma showed TP53 and CIC mutations and an amplification of ERBB2. A transitional cell carcinoma was associated with HPV16 infection. No genetic alteration was found for one adenocarcinoma, not otherwise specified.

CONCLUSIONS

Our study highlights the variety of molecular alterations associated with lacrimal system tumours and emphasises the importance of molecular testing in these tumours, which can reveal potentially targetable mutations. Our results also reinforce the hypothesis of a common physiopathology of all ACCs, regardless of their primary location.

The Landscape of MYB/MYBL1- and Peri-MYB/MYBL1-Associated Rearrangements in Adenoid Cystic Carcinoma

Approximately 60% of adenoid cystic carcinoma (AdCC) cases are positive for MYB::NFIB or MYBL1::NFIB, whereas MYB/MYBL1 oncoprotein, a key driver of AdCC, is overexpressed in most cases. Juxtaposition of superenhancer regions in NFIB and other genes into the MYB/MYBL1 locus is an attractive oncogenic hypothesis for AdCC cases, either negative or positive for MYB/MYBL1::NFIB. However, evidence supporting this hypothesis is insufficient. We examined 160 salivary AdCC cases for rearrangements in MYB/MYBL1 loci and peri-MYB/MYBL1 areas (centromeric and telomeric areas of 10 Mb each) using formalin-fixed, paraffin-embedded tumor sections. For the detection of the rearrangements, we employed conventional fluorescence in situ hybridization split and fusion assays and a 5 Mb fluorescence in situ hybridization split assay. The latter is a novel assay that enabled us to detect any possible splits within a 5 Mb distance of a chromosome. We found MYB/MYBL1- and peri-MYB/MYBL1-associated rearrangements in 149/160 patients (93%). AdCC cases positive for rearrangements in MYB, MYBL1, the peri-MYB area, and the peri-MYBL1 area numbered 105 (66%), 20 (13%), 19 (12%), and 5 (3%), respectively. In 24 peri-MYB/MYBL1 rearrangement-positive cases, 14 (58%) were found to have a juxtaposition of the NFIB or RAD51B locus into the MYB/MYBL1 loci. On comparing with a tumor group positive for MYB::NFIB, a hallmark of AdCC, other genetically classified tumor groups had similar features of overexpression of the MYB transcript and MYB oncoprotein as detected by semiquantitative RT-qPCR and immunohistochemistry, respectively. In addition, clinicopathological and prognostic features were similar among these groups. Our study suggests that peri-MYB/MYBL1 rearrangements may be a frequent event in AdCC and may result in biological and clinicopathological consequences comparable to MYB/MYBL1 rearrangements. The landscape of MYB/MYBL1 and peri-MYB/MYBL1 rearrangements shown here strongly suggests that juxtaposition of superenhancers into MYB/MYBL1 or peri-MYB/MYBL1 loci is an alteration that acts as a key driver for AdCC oncogenesis and may unify MYB/MYBL1 rearrangement-positive and negative cases.

A Review of the Molecular Landscape of Adenoid Cystic Carcinoma of the Lacrimal Gland

Adenoid cystic carcinoma (ACC) has a worldwide incidence of three to four cases per million population. Although more cases occur in the minor and major salivary glands, it is the most common lacrimal gland malignancy. ACC has a low-grade, indolent histological appearance, but is relentlessly progressive over time and has a strong proclivity to recur and/or metastasise. Current treatment options are limited to complete surgical excision and adjuvant radiotherapy. Intra-arterial systemic therapy is a recent innovation. Recurrent/metastatic disease is common due to perineural invasion, and it is largely untreatable as it is refractory to conventional chemotherapeutic agents. Given the rarity of this tumour, the molecular mechanisms that govern disease pathogenesis are poorly understood. There is an unmet, critical need to develop effective, personalised targeted therapies for the treatment of ACC in order to reduce morbidity and mortality associated with the disease. This review details the evidence relating to the molecular underpinnings of ACC of the lacrimal gland, including the MYB-NFIB chromosomal translocations, Notch-signalling pathway aberrations, DNA damage repair gene mutations and epigenetic modifications.

Rearrangements, Expression, and Clinical Significance of MYB and MYBL1 in Adenoid Cystic Carcinoma: A Multi-Institutional Study

Simple Summary

Adenoid cystic carcinoma (ACC) is an aggressive glandular cancer with poor prognosis that preferentially occurs in the head and neck. The MYB and MYBL1 oncogenes are main oncogenic drivers, but the true frequency and clinical significance of these alterations are unclear. Here, we have used tissue microarrays to study these genes in a multi-institutional study of close to 400 ACCs, the largest study to date. We found alterations of MYB/MYBL1 in 78% of the cases and overexpression of the MYB/MYBL1 proteins in 93% of the cases. Importantly, we show that patients with loss of one part of the MYB gene and its neighboring sequences on chromosome 6 have a significantly shorter overall survival compared to those without loss. Our study provides new knowledge about the frequency and clinical significance of MYB/MYBL1 alterations and identifies genes with tumor suppressive functions on chromosome 6 that contribute to poor prognosis in ACC.

Abstract

Adenoid cystic carcinoma (ACC) is an aggressive head and neck malignancy characterized by a t (6;9) translocation resulting in an MYB–NFIB gene fusion or, more rarely, an MYBL1 fusion. The true frequency and clinical significance of these alterations are still unclear. Here, we have used tissue microarrays and analyzed 391 ACCs and 647 non-ACC salivary neoplasms to study the prevalence, expression, and clinical significance of MYB/MYBL1 alterations by FISH and immunohistochemistry. Alterations of MYB or MYBL1 were found in 78% of the cases, of which 62% had MYB alterations and 16% had MYBL1 rearrangements. Overexpression of MYB/MYBL1 oncoproteins was detected in 93% of the cases. MYB split signal, seen in 39% of the cases, was specific for ACC and not encountered in non-ACC salivary tumors. Loss of the 3′-part of MYB was enriched in grade 3 tumors and was a significant independent prognostic biomarker for overall survival in multivariate analyses. We hypothesize that loss of the 3′-part of MYB results from an unbalanced t(6;9) leading to an MYB–NFIB fusion with concomitant loss of the segment distal to the MYB breakpoint in 6q23.3. Our study provides new knowledge about the prevalence and clinical significance of MYB/MYBL1 alterations and indicates the presence of genes with tumor suppressive functions in 6q23.3-qter that contribute to poor prognosis and short overall survival in ACC.

Stereotactic radiosurgery as a successful method to control meningeal metastatic adenoid cystic carcinoma of the lacrimal gland: A case report

Adenoid cystic carcinoma (ACC) of the lacrimal gland is a rare tumor. In addition, considering the lack of data on large groups of patients there is no standard of care to treat patients with multiple meningeal metastases of ACC. A two-year analysis of the course of the disease in a patient with synchronous oligometastatic ACC of the lacrimal gland that was treated with stereotactic radiosurgery (SRS) is presented. The aim of the present case report was to evaluate the effect of SRS in the treatment of a patient with ACC. Preliminary results confirmed that this method was highly effective in this patient. The patient is currently living with a good quality of life, normal vision and with no evidence of disease or complications. SRS exhibited reliable local tumor control and insignificant radiation-related complications, rendering it an encouraging treatment option for patients with recurrent or metastatic ACC.

MYB-NFIB fusion transcript in Adenoid Cystic Carcinoma: current state of knowledge and future directions

Adenoid cystic carcinoma (ACC) is the most common type of salivary gland cancer that can also arise in other primary sites. Regardless of the site, most ACC cases carry a recurrent chromosomal translocation - t(6;9)(q22-23;p23-24) - involving the MYB oncogene and the NFIB transcription factor. Generally, a long sequence of MYB is fused to the terminal exons of NFIB, yet the break can occur in different exons for both genes, resulting in multiple chimeric variants. The fusion status can be determined by a number of methods, each of them with particular advantages. In vitro and in vivo studies have been conducted to understand the biological consequences of MYB-NFIB translocation, and such findings could contribute to improving the current inefficient therapeutic options for disseminated ACC. This review provides a discussion on relevant evidence in the context of ACC MYB-NFIB translocations to determine the current state of knowledge and discuss future directions.

Primary cutaneous adenoid cystic carcinoma: a clinicopathologic, immunohistochemical, and fluorescence in-situ hybridisation study of 13 cases

AIMS

This study aimed to investigate the clinical, histological, immunohistochemical and chromosomal features of primary cutaneous adenoid cystic carcinoma (PCACC).

METHODS AND RESULTS

We retrospectively analysed 13 cases identified on their clinicopathological features and performed fluorescence in-situ hybridisation (FISH) on six available cases. Head and neck (46.2%) were most commonly involved. The median age was 53 years, with a male predilection. Histologically, tumours were classified as grades 1 (eight), 2 (four) and 3 with high-grade transformation (HGT) (one). The HGT component was demonstrated as poorly differentiated carcinoma with multifocal necrosis and myoepithelial differentiation. Patients with one of the following factors: longest diameter of the lesion (≥ 1 cm), involvement of subcutaneous fat tissue and widely infiltrative border had a relatively higher rate of local recurrence, distant metastasis and death. Five of six cases were confirmed to have MYB translocation, while nuclear staining for MYB proto-oncogene, transcription factor (MYB) protein was found in four cases. During the follow-up (median = 64 months), two patients experienced local recurrences. One patient, who was classified as grade III PCACC with HGT, developed multiple metastases and died of disease. Another patient was alive with multiple metastases.

CONCLUSIONS

This is the largest single-institution study, to our knowledge, of PCACC in an Asian population. We describe the first case of scalp PCACC with HGT, which is the only death case in our series. PCACC tends to recur locally and has metastatic potential. PCACC with HGT has a poor prognosis.

Adenoid cystic carcinoma of the palpebral lobe of the lacrimal gland - case report and literature review

Epithelial tumors of the lacrimal gland are rare and usually develop in the orbital lobe. We report the exceedingly rare occurrence of a primary adenoid cystic carcinoma in the palpebral lobe of the lacrimal gland. A 26-year-old female was referred for evaluation of a gradually enlarging mass in the lateral upper eyelid, previously diagnosed as a chalazion. Computed tomography revealed a heterogeneous round lesion anterior to the orbital rim. Excisional biopsy was compatible with an adenoid cystic carcinoma. After excluding distant metastasis, and as the patient refused adjuvant radiotherapy, a second surgical procedure, with wide local excision, was indicated. Follow-up showed no recurrence. This case highlights the importance of performing a thorough clinical examination when diagnosing any lateral upper eyelid mass. A high index of suspicion for malignant tumors of the lacrimal gland should always be maintained, and a complete excision with histological analysis should be preferred whenever possible.

Flaming the fight against cancer cells: the role of microRNA-93

There have been attempts to develop novel anti-tumor drugs in cancer therapy. Although satisfying results have been observed at a consequence of application of chemotherapeutic agents, the cancer cells are capable of making resistance into these agents. This has forced scientists into genetic manipulation as genetic alterations are responsible for generation of a high number of cancer cells. MicroRNAs (miRs) are endogenous, short non-coding RNAs that affect target genes at the post-transcriptional level. Increasing evidence reveals the potential role of miRs in regulation of biological processes including angiogenesis, metabolism, cell proliferation, cell division, and cell differentiation. Abnormal expression of miRs is associated with development of a number of pathologic events, particularly cancer. MiR-93 plays a significant role in both physiological and pathological mechanisms. At the present review, we show how this miR dually affects the proliferation and invasion of cancer cells. Besides, we elucidate the oncogenesis or oncosuppressor function of miR-93.

Solid-type adenoid cystic carcinoma of the breast, a distinct molecular entity enriched in NOTCH and CREBBP mutations

Adenoid cystic carcinoma (ACC) of the breast with a predominant solid pattern is difficult to diagnose with certainty and differentiate from more common triple-negative breast cancers (TNBCs) of basal-phenotype. To better characterize solid ACC, we performed a clinical, morphological, immunohistochemical, and molecular comparative analysis of 33 ACCs of the breast comprising 17 solid variant ACCs and 16 conventional ACCs. Solid ACCs displayed basaloid morphology with an exclusive or predominant epithelial cell population associated with decreased myoepithelial differentiation, while demonstrating MYB protein overexpression similar to the more common type of ACC. Strong and diffuse MYB expression by immunochemistry was observed in 14/17 (82%) of solid ACCs while MYB rearrangements were detected by break apart fluorescence in situ hybridization (FISH) in only 3/16 (19%) of solid ACCs. Conversely, weak MYB immunohistochemical expression was observed in only 7/204 (3%) of TNBC. Solid ACCs displayed a transcriptomic profile distinct from conventional ACCs with 549 genes showing a highly significant differential expression between conventional and solid ACC [false discovery rate (FDR) < 0.01; log2FC > |1|]. EnrichR and Kegg Pathway analyses identified PI3K-Akt and focal adhesion signaling pathways as significantly overexpressed in conventional ACCs compared with solid ACCs which significantly overexpressed the nitrogen metabolism pathway. CREBBP mutations and NOTCH activating gene mutations were only present in solid ACCs, concerning 5/16 (31%) of cases for each gene. Tumors with NOTCH activating mutations displayed a strong diffuse nuclear NICD1 staining, an established marker of Notch pathway activation. Solid ACCs also differed from basal-type TNBC, with fewer TP53 mutations and a more stable genomic profile on array comparative genomic hybridization (CGH). In summary, solid-type ACC of the breast is a distinct molecular entity within the ACC family and is different from common basal-type TNBC. MYB is a diagnostically useful biomarker of solid ACC and NOTCH could be a novel potential therapeutic target in 30% of cases.

Clinical and genomic features of adult and paediatric acute leukaemias with ophthalmic manifestations

Objective

To describe the clinicopathological and genomic features of nine patients with primary and secondary orbital/ocular manifestations of leukaemia.

Methods

All orbital/ocular leukaemic specimens from 1980 to 2009 were collected from the Danish Register of Pathology. In six cases, medical records and formalin-fixed, paraffin-embedded blocks were available. Three cases from the Department of Pathology, Royal Liverpool University Hospital, were also included. Immunophenotypes and MYB oncoprotein expression were ascertained by immunohistochemistry. Genomic imbalances were analysed with comparative genomic hybridisation arrays and oncogene rearrangements with fluorescence in situ hybridisation.

Results

Four patients had B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) and five had acute myeloid leukaemia (AML). Two patients with BCP-ALL and one with AML had primary orbital manifestations of leukaemia. Common symptoms were proptosis, displacement of the eye, and reduced eye mobility in patients with orbital leukaemias and pain, and reduced visual acuity in patients with ocular leukaemias. All patients with primary orbital lesions were alive up to 18 years after diagnosis. All but one patient with secondary ophthalmic manifestations died of relapse/disseminated disease. ETV6 and RUNX1 were rearranged in BCP-ALL, and RUNX1 and KMT2A in AML. Genomic profiling revealed quiet genomes (0–7 aberrations/case). The MYB oncoprotein was overexpressed in the majority of cases.

Conclusions

Leukaemias with and without ophthalmic manifestations have similar immunophenotypes, translocations/gene fusions and copy number alterations. Awareness of the clinical spectrum of leukaemic lesions of the eye or ocular region is important to quickly establish the correct diagnosis and commence prompt treatment.

Detecting MYB and MYBL1 fusion genes in tracheobronchial adenoid cystic carcinoma by targeted RNA-sequencing

Primary tracheobronchial adenoid cystic carcinoma is rare, accounting for less than 1% of all lung tumors. Many adenoid cystic carcinomas have been reported to have a specific chromosome translocation t(6;9)/MYB-NFIB. More recently, t(8;9)/MYBL1-NFIB gene fusion was reported in salivary gland adenoid cystic carcinomas which lacked a t(6;9)/MYB-NFIB. Two prior studies showed t(6;9)/MYB-NFIB in tracheobronchial adenoid cystic carcinoma; however, only rare cases of MYBL1 rearrangement have been reported in this carcinoma. In this study, we used targeted RNA sequencing to investigate fusion genes in tracheobronchial adenoid cystic carcinoma at our institution. Fusions of either MYB or MYBL1 genes were detected in 7 of 7 carcinomas. Three cases had MYB-NFIB, and 3 had MYBL1-NFIB. The remaining case showed a rare MYBL1-RAD51B fusion. These findings suggest that rearrangement involving MYB or MYBL1 is a hallmark of tracheobronchial adenoid cystic carcinoma.

A Case of Lacrimal Gland Ductal Carcinoma With Regional Lymph Node Metastasis

Ductal carcinoma of the lacrimal gland is a very rare and aggressive neoplasm, with clinical and histopathologic similarities to salivary ductal carcinoma. Of the 25 previously reported cases, 2 patients had metastases to local lymph nodes confirmed on pathologic examination. The authors now report the clinical presentation, histopathologic and immunohistochemical features, and the treatment of a third patient with lacrimal gland ductal carcinoma with spread to local lymph nodes. In contrast to ductal carcinoma, lymph node involvement has not been reported in the largest series of adenoid cystic carcinoma, a much more common lacrimal gland malignancy. This case highlights the need for possible lymph node surveillance in patients with lacrimal gland ductal carcinoma.

Analysis of clinicopathological characteristics, MYB rearrangement and prognostic factors in salivary adenoid cystic carcinoma

Recent studies have indicated that a recurrent t(6;9)(q22-23;p23-24) chromosomal translocation in salivary adenoid cystic carcinoma (ACC) results in a MYB proto-oncogene transcription factor-nuclear factor I/B (MYB-NFIB) gene fusion, which has not previously been detected in any non-ACC carcinomas of the head and neck. In the present study, data on clinical factors affecting the survival rate of patients with salivary ACC from a single institution was retrospectively analyzed, and the frequency of MYB gene rearrangement determined. A total of 97 patient cases were analyzed, and young adults presenting with ACC (<40 years old) accounted for 19.6% of all patients (n=19). A total of 70.1% (n=68) displayed neurological symptoms, including pain, paraesthesia, tongue deviation, and facial paralysis. A marked majority of the analyzed tumors (85.6%) displayed evidence of MYB rearrangement. MYB rearrangement was significantly higher in patients with late Tumor-Node-Metastasis (TNM) stage cancer compared with that in patients with early TNM stage (P=0.033), as detected by a dual color MYB break-apart fluorescence in situ hybridization probe. Kaplan-Meier analysis revealed significant differences in patient overall survival (OS) time with regard to age, gender, TNM stage, neurological symptoms, margin status and MYB rearrangement. Specifically, young age was significantly associated with a shorter OS time. In summary, the present study suggested that young patients with salivary ACC presented with a worse prognosis, in contrast to the majority of patients with salivary ACC. Moreover, MYB alterations exhibited a high positive rate in salivary ACC, and therefore, the absence of MYB rearrangements may be associated with a better prognosis.

Small Subset of Adenoid Cystic Carcinoma of the Skin Is Associated With Alterations of the MYBL1 Gene Similar to Their Extracutaneous Counterparts

Adenoid cystic carcinoma (ACC) of the skin is a rare malignant neoplasm histologically identical to homonymous tumors in other organs. Cutaneous ACC has been found to harbor MYB gene activations, either through MYB chromosomal abnormalities or by generation of the MYB-NFIB fusion. In salivary gland ACC, in addition to the MYB gene, alterations in MYBL1, the gene closely related to MYB, have been reported. We studied 10 cases of cutaneous ACC (6 women, 4 men; and age range 51-83 years) for alterations in the MYB, NFIB, and MYBL1 genes, using FISH and PCR. MYB break-apart and NFIB break-apart tests were positive in 4 and 5 cases, respectively. MYB-NFIB fusions were found in 4 cases. The break of MYBL1 was found in 2 cases, and in one of them, the NFIB break-apart probe was positive, strongly indicating a MYBL1-NFIB fusion. In 2 cases, the MYB break-apart test was positive, whereas no MYB-NFIB was detected, strongly suggesting another fusion partner. It is concluded that MYBL1 alterations are detected in primary cutaneous ACC but are apparently less common compared with MYB and NFIB alterations.

c-MYB and DMTF1 in Cancer

The c-Myb gene encodes a transcription factor that regulates cell proliferation, differentiation, and apoptosis through protein-protein interaction and transcriptional regulation of signaling pathways. The protein is frequently overexpressed in human leukemias, breast cancers, and other solid tumors suggesting that it is a bona fide oncogene. c-MYB is often overexpressed by translocation in human tumors with t(6;7)(q23;q34) resulting in c-MYB-TCRβ in T cell ALL, t(X;6)(p11;q23) with c-MYB-GATA1 in acute basophilic leukemia, and t(6;9)(q22-23;p23-24) with c-MYB-NF1B in adenoid cystic carcinoma. Antisense oligonucleotides to c-MYB were developed to purge bone marrow cells to eliminate tumor cells in leukemias. Recently, small molecules that inhibit c-MYB activity have been developed to disrupt its interaction with p300. The Dmp1 (cyclin D binding myb-like protein 1; Dmtf1) gene was isolated through its virtue for binding to cyclin D2. It is a transcription factor that has a Myb-like repeat for DNA binding. The Dmtf1 protein directly binds to the Arf promoter for transactivation and physically interacts with p53 to activate the p53 pathway. The gene is hemizygously deleted in 35-42% of human cancers and is associated with longer survival. The significances of aberrant expression of c-MYB and DMTF1 proteins in human cancers and their clinical significances are discussed.

PLAG1, SOX10, and Myb Expression in Benign and Malignant Salivary Gland Neoplasms

Background

Recent findings in molecular pathology suggest that genetic translocation and/or overexpression of oncoproteins is important in salivary gland tumorigenesis and diagnosis. We investigated PLAG1, SOX10, and Myb protein expression in various salivary gland neoplasm tissues.

Methods

A total of 113 cases of surgically resected salivary gland neoplasms at the National Cancer Center from January 2007 to March 2017 were identified. Immunohistochemical staining of PLAG1, SOX10, and Myb in tissue samples was performed using tissue microarrays.

Results

Among the 113 cases, 82 (72.6%) were benign and 31 (27.4%) were malignant. PLAG1 showed nuclear staining and normal parotid gland was not stained. Among 48 cases of pleomorphic adenoma, 29 (60.4%) were positive for PLAG1. All other benign and malignant salivary gland neoplasms were PLAG1-negative. SOX10 showed nuclear staining. In normal salivary gland tissues SOX10 was expressed in cells of acinus and intercalated ducts. In benign tumors, SOX10 expression was observed in all pleomorphic adenoma (48/48), and basal cell adenoma (3/3), but not in other benign tumors. SOX10 positivity was observed in nine of 31 (29.0%) malignant tumors. Myb showed nuclear staining but was not detected in normal parotid glands. Four of 31 (12.9%) malignant tumors showed Myb positivity: three adenoid cystic carcinomas (AdCC) and one myoepithelial carcinoma with focal AdCC-like histology.

Conclusions

PLAG1 expression is specific to pleomorphic adenoma. SOX10 expression is helpful to rule out excretory duct origin tumor, but its diagnostic value is relatively low. Myb is useful for diagnosing AdCC when histology is unclear in the surgical specimen.

Recurrent rearrangements of the PLAG1 and HMGA2 genes in lacrimal gland pleomorphic adenoma and carcinoma ex pleomorphic adenoma

PURPOSE

Lacrimal gland tumours constitute a wide spectrum of neoplastic lesions that are histologically similar to tumours of the salivary gland. In the salivary gland, pleomorphic adenoma (PA) is frequently characterized by recurrent chromosomal rearrangements of the PLAG1 and HMGA2 genes, a genetic feature retained in carcinoma ex pleomorphic adenoma (ca-ex-PA) that makes it possible to distinguish ca-ex-PA from de novo carcinomas. However, whether PLAG1 and HMGA2 gene rearrangements are found in lacrimal gland PA and ca-ex-PA is not known.

METHODS

Twenty-one lacrimal gland PAs and four ca-ex-PAs were retrospectively reviewed and subjected to break-apart fluorescence in situ hybridization (FISH) for rearrangements of the PLAG1 gene. Cases without PLAG1 abnormalities were subjected to HMGA2 break-apart FISH. Immunohistochemical staining for PLAG1 and HMGA2 protein was performed and correlated with gene status.

RESULTS

Sixteen of 21 PAs showed rearrangement of PLAG1 and were all positive for PLAG1 protein. Two of the remaining five PAs showed rearrangement of HMGA2 and were the only cases positive for HMGA2 with immunohistochemistry. The three FISH-negative PAs expressed PLAG1 protein. All four ca-ex-PAs showed rearrangement of PLAG1 and expressed PLAG1 protein. None of the de novo carcinomas showed rearrangement of either of the two genes or expression of the two proteins.

CONCLUSION

Rearrangement of PLAG1 and HMGA2 and expression of the corresponding proteins are frequent and specific findings in lacrimal gland PA and ca-ex-PA. The mechanism for PLAG1 overexpression in FISH-negative PAs is yet to be clarified.

Overview of benign and malignant lacrimal gland tumors

PURPOSE OF REVIEW

The goal of this article is to review the key clinical and radiological features, treatment strategies, and prognosis of lacrimal gland tumors.

RECENT FINDINGS

Debulking of the orbital lobe of the lacrimal gland may offer improved control rates in dacryoadenitis without compromise of tear film function. Contrary to previous belief, careful biopsy of the lacrimal gland prior to excision does not appear to increase the risk of recurrence in cases with suspected pleomorphic adenoma. Low-dose radiation (4 Gy) in two 2-Gy fractions appears to be effective and well tolerated in indolent non-Hodgkin lymphoma of the ocular adnexa with high local control rate. Eye-sparing surgery for adenoid cystic carcinoma (ACC) leaving minimal or no tumor residual in the orbit followed by adjuvant radiation therapy or chemoradiotherapy may provide good local control and long-term survival outcomes. Intra-arterial chemotherapy has been found to decrease recurrence and improve survival in ACC and can also be used as part of an eye-sparing treatment strategy. The development of targeted drugs may offer palliation for patients with unresectable or metastatic disease in lacrimal gland carcinoma.

SUMMARY

This article offers an update on diagnosis, management, and prognosis of the major lacrimal gland lesions.

Adenoid cystic carcinomas of the salivary gland, lacrimal gland, and breast are morphologically and genetically similar but have distinct microRNA expression profiles

Adenoid cystic carcinoma is among the most frequent malignancies in the salivary and lacrimal glands and has a grave prognosis characterized by frequent local recurrences, distant metastases, and tumor-related mortality. Conversely, adenoid cystic carcinoma of the breast is a rare type of triple-negative (estrogen and progesterone receptor, HER2) and basal-like carcinoma, which in contrast to other triple-negative and basal-like breast carcinomas has a very favorable prognosis. Irrespective of site, adenoid cystic carcinoma is characterized by gene fusions involving MYB, MYBL1, and NFIB, and the reason for the different clinical outcomes is unknown. In order to identify the molecular mechanisms underlying the discrepancy in clinical outcome, we characterized the phenotypic profiles, pattern of gene rearrangements, and global microRNA expression profiles of 64 salivary gland, 9 lacrimal gland, and 11 breast adenoid cystic carcinomas. All breast and lacrimal gland adenoid cystic carcinomas had triple-negative and basal-like phenotypes, while salivary gland tumors were indeterminate in 13% of cases. Aberrations in MYB and/or NFIB were found in the majority of cases in all three locations, whereas MYBL1 involvement was restricted to tumors in the salivary gland. Global microRNA expression profiling separated salivary and lacrimal gland adenoid cystic carcinoma from their respective normal glands but could not distinguish normal breast adenoid cystic carcinoma from normal breast tissue. Hierarchical clustering separated adenoid cystic carcinomas of salivary gland origin from those of the breast and placed lacrimal gland carcinomas in between these. Functional annotation of the microRNAs differentially expressed between salivary gland and breast adenoid cystic carcinoma showed these as regulating genes involved in metabolism, signal transduction, and genes involved in other cancers. In conclusion, microRNA dysregulation is the first class of molecules separating adenoid cystic carcinoma according to the site of origin. This highlights a novel venue for exploring the biology of adenoid cystic carcinoma.

Polymorphous Sweat Gland Carcinoma: An Immunohistochemical and Molecular Study

Polymorphous sweat gland carcinoma is an uncommon low-grade malignant adnexal tumor with a marked predilection for the distal extremities. Histologically, the lesions are characterized by a cellular proliferation showing a combination of growth patterns, including trabecular, solid, tubular, cribriform, or adenoid cystic and pseudopapillary. The immunohistochemical and molecular profile of these tumors has not yet been properly addressed. We have studied 3 cases of polymorphous sweat gland carcinoma using a broad panel of immunohistochemical markers including cytokeratin AE1/AE3, CK5/6, MOC31, p40, p63, p16, chromogranin, synaptophysin, CD56, MIB-1, estrogen receptor, progesterone receptor, androgen receptor, BER-EP4, smooth muscle actin, epithelial membrane antigen, carcinoembryonic antigen, CD117, S100 protein, HBME-1, DOG1, vimentin, and mammaglobin. We also examined for the MYB-NFIB fusion by fluorescent in situ hybridization (ISH) and for human papilloma virus by ISH. Our studies show that cytokeratin AE1/AE3, CK5/6, p40, p63, p16, chromogranin, and CD56 stains were positive in all 3 cases. All 3 cases were negative for MYB-NFIB fusion by fluorescent ISH which rules out adenoid cystic carcinoma. DNA ISH studies for high-risk human papilloma virus were negative in all cases. MIB-1 proliferation index was very high (30%-70% nuclear positivity), supporting a malignant phenotype. The positivity for chromogranin and CD56 suggests partial neuroendocrine differentiation. The differential diagnosis includes metastases from internal malignancies, basal cell carcinoma, and other benign and malignant adnexal neoplasms such as adenoid cystic carcinoma, ductal eccrine carcinoma, and microcystic carcinoma. Positivity for p16 in combination with chromogranin and CD56 may be potentially good markers for differentiating this tumor from other adnexal tumors.

MYB and MYBL1 in adenoid cystic carcinoma: diversity in the mode of genomic rearrangement and transcripts

MYB-NFIB and MYBL1-NFIB have been reported in ~60% of adenoid cystic carcinoma cases, but driver alterations in the remaining ~40% of adenoid cystic carcinoma remain unclear. We examined 100 adenoid cystic carcinoma cases for MYB and MYBL1 locus rearrangements by fluorescence in situ hybridization (FISH) with originally designed probe sets using formalin-fixed paraffin-embedded materials. Approximately one-third of samples were also analyzed by fusion transcript-specific RT-PCR and capture RNA sequencing. In the 27 cases with frozen materials, MYB-NFIB and MYBL1-NFIB fusion transcripts were detected in 9 (33%) and 6 cases (22%) by RT-PCR, respectively. Meanwhile, high expression of MYB (18 cases, 67%) or MYBL1 (9 cases, 33%) was detected in all 27 cases in a mutually exclusive manner, regardless of its form (full-length, truncation, or fusion transcript). Interestingly, genomic rearrangements around the corresponding highly-expressed gene were observed in all 27 cases by FISH, suggesting a causative relationship between genomic rearrangements and gene expression. Among the 100 cases, including additional 73 cases, 97 harbored genomic rearrangements in the MYB (73 cases) or MYBL1 locus (24 cases) including 10 cases with atypical FISH patterns undetectable through ordinary split FISH approaches: breakpoints far distant from MYB (5 cases) and a small NFIB locus insertion into the MYB (3 cases) or MYBL1 locus (2 cases). In clinicopathological analyses, histological grade, primary tumor size, and lymph node metastasis were identified as prognostic factors, whereas MYB/MYBL1 rearrangements were not, but were associated with histological grade. In the present study, MYB or MYBL1 locus rearrangement was detected in nearly all adenoid cystic carcinoma cases, and therefore it would be a good diagnostic marker for adenoid cystic carcinoma. However, fusion transcript-specific RT-PCR for MYB-NFIB and MYBL1-NFIB and ordinary split FISH assays for MYB and MYBL1 were less sensitive, and thus detection methods should be judiciously designed because of the diversity of rearrangement modes in adenoid cystic carcinoma.

miR-93-5p enhance lacrimal gland adenoid cystic carcinoma cell tumorigenesis by targeting BRMS1L

Background

Lacrimal adenoid cystic carcinoma (LACC) is one of the most common malignancies that affects lacrimal gland. MicroRNAs are known to play a crucial role as oncogenes or tumor suppressors. Specifically, miR-93 has been reported to play a crucial role in colorectal, breast, pancreatic, lung cancer and hepatocellular carcinoma. However, the role of miR-93 in LACC and the potential molecular mechanisms involved remain unknown. Therefore, we took the challenge to determine the involvement of miR-93 in the LACC by targeting BRMS1L.

Method

A total of 5 adenoid cystic carcinoma (ACC) of lacrimal gland patient tissues and their plasma were examined. Three normal lacrimal glands and three normal serums were collected as a control group. After surgical resection, the specimens were preserved in liquid nitrogen and stored at − 80 °C until RNA extraction. Afterwards, LACC cells with miR-93-5p overexpression were subjected to qRT-PCR and western blot for epithelial–mesenchymal transition (EMT) markers levels. Ability of LACC cell migration, invasion, proliferation and apoptosis was examined by wounded healing, transwell, CCK-8 and apoptosis assays. Afterwards, TargetScan was used to predict putative targets of miR-93-5p. Then, the examination was performed whether miR-93-5p targets BRMS1L by the use of luciferase reporter assays and western blotting. Finally, immunohistochemical staining was sone and all the images were taken using a microscope (Nikon, Tokyo).

Results

Our results showed that miR-93 was overexpressed in tissues and plasma of LACC patients compared to healthy controls. MiR-93 downregulated E-cadherin expression while increasing N-cadherin expression and significantly inhibited luciferase activity. Furthermore, western blotting results confirmed that miR-93-5p could inhibit BRMS1L expression. The BRMS1L staining in LACC tissues was weaker than in normal controls. In addition, miR-93-5p revealed a reverse correlation with the expression of BRMS1L. In addition, significant upregulation of E-cadherin and downregulation of N-cadherin were found when LACC cells were transfected with BRMS1L. Finally, miR-93-5p significantly enhanced TOP/FOP luciferase activity. Upregulation of BRMS1L reduced TOP/FOP luciferase activity while further overexpression of miR-93-5p could not rescue Wnt signaling activity.

Conclusions

Our findings report that miR-93 promotes LACC cell migration, invasion, and proliferation via targeting downregulation of BRMS1L through regulation of Wnt signaling pathway.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0552-9) contains supplementary material, which is available to authorized users.

Adenoid cystic carcinoma: emerging role of translocations and gene fusions

Adenoid cystic carcinoma (ACC), the second most common salivary gland malignancy, is notorious for poor prognosis, which reflects the propensity of ACC to progress to clinically advanced metastatic disease. Due to high long-term mortality and lack of effective systemic treatment, the slow-growing but aggressive ACC poses a particular challenge in head and neck oncology. Despite the advancements in cancer genomics, up until recently relatively few genetic alterations critical to the ACC development have been recognized. Although the specific chromosomal translocations resulting in MYB-NFIB fusions provide insight into the ACC pathogenesis and represent attractive diagnostic and therapeutic targets, their clinical significance is unclear, and a substantial subset of ACCs do not harbor the MYB-NFIB translocation. Strategies based on detection of newly described genetic events (such as MYB activating super-enhancer translocations and alterations affecting another member of MYB transcription factor family-MYBL1) offer new hope for improved risk assessment, therapeutic intervention and tumor surveillance. However, the impact of these approaches is still limited by an incomplete understanding of the ACC biology, and the manner by which these alterations initiate and drive ACC remains to be delineated. This manuscript summarizes the current status of gene fusions and other driver genetic alterations in ACC pathogenesis and discusses new therapeutic strategies stemming from the current research.

Therapeutic targeting of oncogenic transcription factors by natural products in eye cancer

Carcinogenesis has a multifactorial etiology, and the underlying molecular pathogenesis is still not entirely understood, especially for eye cancers. Primary malignant intraocular neoplasms are relatively rare, but delayed detection and inappropriate management contribute to poor outcomes. Conventional treatment, such as orbital exenteration, chemotherapy, or radiotherapy, alone results in high mortality for many of these malignancies. Recent sequential multimodal therapy with a combination of high-dose chemotherapy, followed by appropriate surgery, radiotherapy, and additional adjuvant chemotherapy has helped dramatically improve management. Transcription factors are proteins that regulate gene expression by modulating the synthesis of mRNA. Since transcription is a dominant control point in the production of many proteins, transcription factors represent key regulators for numerous cellular functions, including proliferation, differentiation, and apoptosis, making them compelling targets for drug development. Natural compounds have been studied for their potential to be potent yet safe chemotherapeutic drugs. Since the ancient times, plant-derived bioactive molecules have been used to treat dreadful diseases like cancer, and several refined pharmaceutics have been developed from these compounds. Understanding targeting mechanisms of oncogenic transcription factors by natural products can add to our oncologic management toolbox. This review summarizes the current findings of natural products in targeting specific oncogenic transcription factors in various types of eye cancer.

Whole Exome Sequencing of Lacrimal Gland Adenoid Cystic Carcinoma

Purpose

To identify genomic mutations in lacrimal gland adenoid cystic carcinoma (LGACC) samples from patients.

Methods

Genomic DNA was extracted from LGACC specimens. Whole exome sequencing (exome-seq) was conducted to screen for mutations. Capillary sequencing was performed to verify mutations in genes shared by multiple samples. Luciferase assays were used to evaluate functional consequences of NOTCH1 mutations.

Results

The mutation profile of LGACC was complicated. The most frequently mutated gene observed (28.6%) was bromodomain PHD finger transcription factor (BPTF). No mutation was identified in common cancer genes such as TP53, KRAS, and BRAF. However, mutations predicted to be functionally severe were accumulated in the Notch signaling pathway including NOTCH1 and NOTCH2, of which mutations have been reported in head/neck adenoid cystic carcinoma (ACC). Of 14 LGACC samples, five samples carry mutations in Notch pathway genes. Capillary sequencing verified all the mutations in the two NOTCH genes identified by exome-seq. Compared to the wild-type NOTCH1, three frame shifting mutations and two missense mutations (C387W and L1600Q) increased luciferase activity approximately 10- to 25-fold.

Conclusions

Major genomic mutation profiles in LGACC were uncovered by exome-seq. Although preliminary in nature, the Notch pathway could be a potential therapeutic target for LGACC.

An Update on Tumors of the Lacrimal Gland

Lacrimal gland tumors are rare and constitute a wide spectrum of different entities ranging from benign epithelial and lymphoid lesions to high-grade carcinomas, lymphomas, and sarcomas with large differences in prognosis and clinical management. The symptoms and findings of a lacrimal gland lesion are a growing mass at the site of the lacrimal gland, including displacement of the eyeball, decreased motility, diplopia, and ptosis. Pain is the cardinal symptom of an adenoid cystic carcinoma. Radiological findings characteristically include an oval, well-demarcated mass for benign lesions whereas malignant lesions typically display calcifications, destruction of bone, and invasion of adjacent structures. The diagnosis ultimately relies on histology, as does the choice of treatment and the prognosis. In recent years, the understanding of the biology of numerous types of lacrimal gland neoplasia has improved and the choice of treatment has changed accordingly and holds further promise for future targeted therapies. Treatment of benign epithelial lesions is surgical excision whereas carcinomas often require adjuvant radiotherapy and/or chemotherapy. In contrast, the cornerstone in management of lymphoid lesions is chemotherapy, often including a monoclonal antibody. This article presents an update on the clinical, radiological, histological, and molecular features, along with treatment strategies for tumors of the lacrimal gland.

Adenoid cystic carcinoma of the lacrimal gland is frequently characterized by MYB rearrangement

PurposeAdenoid cystic carcinoma (ACC) represents ~10-15% of salivary neoplasms and almost universally exhibits a lethal clinical course. ACC is also known to occur in the lacrimal gland. ACC is characterized by its heterogeneous morphology and may demonstrate tubular, cribriform, and/or solid architectural patterns. Unfortunately, these histopathological features are not specific to ACC and can be seen in other salivary gland-type neoplasms, introducing a diagnostic dilemma. The discovery of fusion transcripts has revolutionized the diagnosis, surveillance, and treatment of epithelial malignancies. In several anatomic subsites ACC is frequently characterized by a fusion transcript involving genes MYB and NFIB; more specifically, t(6;9)(q22-23;p23-24). This study explores the incidence of MYB rearrangement in cases of lacrimal gland ACC using fluorescent in situ hybridization.Materials and methodsRetrospective clinical and histopathological review of 12 cases of lacrimal gland ACC seen at Mayo Clinic over a 25-year period (1990-2015) was performed. Demographic and clinical data were obtained from medical records. Surgical pathology archival material including H&E slides and immunostains was re-examined. Formalin-fixed paraffin-embedded material was further evaluated using immunohistochemistry when appropriate. Fluorescent in situ hybridization (FISH) using a MYB break-apart probe was applied to all histologically confirmed cases of ACC and benign salivary gland parenchyma.ResultsThe median patient age was 53.6 years (range 12-64) and distributed equally by gender (six male and six female). Rearrangement of MYB was identified using FISH in seven cases (58%). Twenty-five sections of benign salivary gland parenchyma showed no evidence of MYB rearrangement. Primary surgical resection was most common treatment, and 78% of the patient received adjuvant radiation therapy. Median overall survival (OS) was 11 years. Rearrangement of MYB did not affect OS.ConclusionsIn summary, our results indicate that the MYB rearrangement defines a significant subset of lacrimal gland ACCs. Importantly, FISH for MYB rearrangement may be used as a diagnostic tool during pathological examination of lacrimal gland neoplasms. Our results showed no relationship between rearrangement status and clinical outcome. Lastly, the presence of t(6;9) in ACC may provide a platform for molecular-targeting strategies in the future.

Primary intraosseous adenoid cystic carcinoma of the mandible: a comprehensive review and analysis of four new cases with emphasis on morphologic, immunophenotypic, and molecular characteristics

OBJECTIVE

To comprehensively review the clinical manifestations, imaging, diagnosis, treatment, and pathologic features of primary intraosseous adenoid cystic carcinoma (PIACC) of the mandible and analyze PIACC histopathology and molecular features in four cases.

STUDY DESIGN

We reviewed the literature and retrospectively studied four cases of PIACC.

RESULTS

The clinical and imaging findings of PIACC are similar to other malignant or borderline-malignant mandible tumors. The four cases of PIACC included three males and one female (aged between 41 and 58 years). The histopathologic features of the tumors resembled those of ACC. We observed abundant osteoclasts resorbing bone at the leading edge of the tumors characterized by solid structure histology but not by the cribriform subtype. Additionally, all four cases showed abnormalities in the MYB gene and high expression of MYB protein. All patients survived for the duration of follow-up, and two patients had distant metastases (followed up for 3 to 36 months).

CONCLUSIONS

PIACC is extremely rare and is often clinically misdiagnosed. Different histologic subtypes could show different mechanisms of invasion of the mandible. MYB gene and protein expression abnormalities can be used as indicators for the precise diagnosis of PIACC.

Overexpression of MYB drives proliferation of CYLD-defective cylindroma cells

Cutaneous cylindroma is an adnexal tumour with apocrine differentiation. A predisposition to multiple cylindromas is seen in patients with Brooke-Spiegler syndrome, who carry germline mutations in the tumour suppressor gene CYLD. Previous studies of inherited cylindromas have highlighted the frequent presence of bi-allelic truncating CYLD mutations as a recurrent driver mutation. We have previously shown that sporadic cylindromas express either MYB-NFIB fusion transcripts or show evidence of MYB activation in the absence of such fusions. Here, we investigated inherited cylindromas from several families with germline CYLD mutations for the presence of MYB activation. Strikingly, none of the inherited CYLD-defective (n = 23) tumours expressed MYB-NFIB fusion transcripts. However, MYB expression was increased in the majority of tumours (69%) and global gene expression analysis revealed that well-established MYB target genes were up-regulated in CYLD-defective tumours. Moreover, knock-down of MYB expression caused a significant reduction in cylindroma cell proliferation, suggesting that MYB is also a key player and oncogenic driver in inherited cylindromas. Taken together, our findings suggest molecular heterogeneity in the pathogenesis of sporadic and inherited cutaneous cylindromas, with convergence on MYB activation. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Myths in the Diagnosis and Management of Orbital Tumors

Orbital tumors constitute a group of diverse lesions with a low incidence in the population. Tumors affecting the eye and ocular adnexa may also secondarily invade the orbit. Lack of accumulation of a sufficient number of cases with a specific diagnosis at various orbital centers, the paucity of prospective randomized studies, animal model studies, tissue bank, and genetic studies led to the development of various myths regarding the diagnosis and treatment of orbital lesions in the past. These myths continue to influence the diagnosis and treatment of orbital lesions by orbital specialists. This manuscript discusses some of the more common myths through case summaries and a review of the literature. Detailed genotypic analysis and genetic classification will provide further insight into the pathogenesis of many orbital diseases in the future. This will enable targeted treatments even for diseases with the same histopathologic diagnosis. Phenotypic variability within the same disease will be addressed using targeted treatments.

Detection of MYB Alterations and Other Immunohistochemical Markers in Primary Cutaneous Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) can arise in several organs, and prognosis is highly dependent on the primary tumor site. Primary cutaneous ACC has an excellent prognosis compared with salivary or lacrimal ACC. Activation of MYB by gene fusion or other mechanisms has been found in salivary, breast, and lacrimal ACCs but has not been described in cutaneous ACC. We analyzed the histopathologic and immunohistochemical features of 19 primary cutaneous ACCs, 2 periorbital ACCs, and 12 salivary gland ACCs and assessed for MYB activation in primary cutaneous ACC by immunohistochemistry and molecular methods. The presence of perineural invasion differed significantly among ACCs of various sites (83% salivary, 50% eyelid, 11% skin, P=0.0002). Over 90% of all ACCs were grade 1 or 2 and exhibited diffuse (>50%) positivity with CD117, SOX-10, and smooth muscle actin immunostains. CK15 and vimentin showed diffuse positivity in 36% and 57% of cutaneous ACCs, respectively, and were negative or only focally positive in all salivary ACCs (P=0.04 and 0.002). Six of the 11 cutaneous and periorbital ACCs tested with reverse transcriptase polymerase chain reaction and/or fluorescence in situ hybridization had MYB rearrangements including 2 cases that expressed MYB-NFIB fusion transcripts. Diffuse expression of MYB protein assessed by immunostaining was present in 8 of 9 cutaneous ACCs, including cases both with and without MYB rearrangements. These results indicate that cutaneous ACCs possess the same types of MYB alterations as ACCs of other anatomic sites. Vimentin and CK15 appear to have some discriminatory value in differentiating between primary cutaneous and salivary gland ACCs.

Tumors of the lacrimal gland

Tumors of the lacrimal gland comprise a wide spectrum, of which the most common demonstrate epithelial and lymphoid differentiation. The diagnosis of lacrimal gland tumors depends primarily on histological evaluation, as do the choice of treatment and prognosis. For some lacrimal gland neoplasms, such as adenoid cystic carcinoma, the outlook is grave. Optimal treatment for several lacrimal gland tumors is also a matter of controversy. However, recent progress has been made in the molecular and genetic understanding of tumorigenesis for such lesions. This article presents an overview of the histopathology of lacrimal gland tumors, together with their epidemiological features, clinical characteristics, and treatment strategies.

Intestinal-specific activatable Myb initiates colon tumorigenesis in mice

Transcription factor Myb is overexpressed in most colorectal cancers (CRC). Patients with CRC expressing the highest Myb are more likely to relapse. We previously showed that mono-allelic loss of Myb in an Adenomatous polyposis coli (APC)-driven CRC mouse model (Apc^Min/+) significantly improves survival. Here we directly investigated the association of Myb with poor prognosis and how Myb co-operates with tumor suppressor genes (TSGs) (Apc) and cell cycle regulator, p27. Here we generated the first intestinal-specific, inducible transgenic model; a MybER transgene encoding a tamoxifen-inducible fusion protein between Myb and the estrogen receptor-α ligand-binding domain driven by the intestinal-specific promoter, Gpa33. This was to mimic human CRC with constitutive Myb activity in a highly tractable mouse model. We confirmed that the transgene was faithfully expressed and inducible in intestinal stem cells (ISCs) before embarking on carcinogenesis studies. Activation of the MybER did not change colon homeostasis unless one p27 allele was lost. We then established that MybER activation during CRC initiation using a pro-carcinogen treatment, azoxymethane (AOM), augmented most measured aspects of ISC gene expression and function and accelerated tumorigenesis in mice. CRC-associated symptoms of patients including intestinal bleeding and anaemia were faithfully mimicked in AOM-treated MybER transgenic mice and implicated hypoxia and vessel leakage identifying an additional pathogenic role for Myb. Collectively, the results suggest that Myb expands the ISC pool within which CRC is initiated while co-operating with TSG loss. Myb further exacerbates CRC pathology partly explaining why high MYB is a predictor of worse patient outcome.

Avoiding the major complication of ophthalmic pathology: misdiagnosis. A review of three common diagnostic challenges

Diagnostic errors in ophthalmic pathology are not uncommon. Pathology is a very subjective specialty with several biases dependent on such factors as training, experience, practice patterns, personal anecdotes, and inevitable human error. In addition to these factors, there are many cases where difficulty in diagnosis lies in differentiating between two very closely related, or similar appearing, entities that may have vastly different prognostic consequences. In this paper, we review three challenging areas wherein diagnostic dilemmas may occur. We outline some of the lessons we have learned in arriving at a correct diagnosis, which includes an admission of one's own limitations requiring consultation with other pathology subspecialists, and the use of immunohistochemistry.

Expression of metabolism-related proteins in lacrimal gland adenoid cystic carcinoma

OBJECTIVES

To investigate the expression and the clinical implications of metabolism-related proteins in lacrimal gland adenoid cystic carcinoma (ACC) in comparison with salivary gland ACC.

METHODS

Human tissue samples of lacrimal gland ACC (n = 11) and salivary gland ACC (n = 64) were analyzed. Immunochemistry was used to measure expression of proteins related to glycolysis (glucose transporter 1, hexokinase II, carbonic anhydrase IX, and monocarboxylate transporter 4 [MCT4]), glutaminolysis (glutaminase 1 [GLS1], glutamate dehydrogenase [GDH], and amino acid transporter 2 [ASCT2]), mitochondria (adenosine triphosphate [ATP] synthase, succinate dehydrogenase A [SDHA], and succinate dehydrogenase B), and glycolytic intermediate metabolism (phosphoserine phosphatase [PSPH], serine hydroxymethyl transferase 1 [SHMT1]).

RESULTS

GLS1 and ASCT2 were more highly expressed, and GDH, ATP synthase, and SDHA were expressed to a lesser degree in lacrimal gland ACC than in salivary gland ACC (P < .05). Lacrimal gland ACC showed less of a mitochondrial phenotype than did salivary gland ACC (P = .001). Positivity of MCT4 and PSPH was related to shorter disease-free survival, and SHMT1 was related to shorter overall survival (P < .05).

CONCLUSIONS

Lacrimal gland ACC exhibited higher expression of GLS1 and ASCT2, compared with salivary gland ACC. Overexpression of MCT4, PSPH, and SHMT1 was associated with poorer prognosis.