Comprehensive genomic profiling of salivary gland carcinoma: Analysis of the Center for Cancer Genomics and Advanced Therapeutics database in Japan.

Comprehensive information on genetic alterations in salivary gland cancer (SGC) is limited. This study aimed to elucidate the genetic and clinical characteristics of patients with SGC using the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database, a Japanese national genomic database. We analyzed data of 776 patients with SGC registered in the C-CAT database between June 1, 2019, and June 30, 2023. Adenoid cystic carcinoma was the most common histologic type, followed by salivary duct carcinoma (SDC) and adenocarcinoma not otherwise specified. Genetic data of 681 patients receiving FoundationOne® CDx were analyzed. We identified specific features of the combination of TP53 and CDKN2A alterations among the histological types. Specific LYN amplification was mainly detected in carcinoma ex pleomorphic adenoma and myoepithelial carcinoma. For SDC, the frequency of ERBB2 and BRAF alterations were higher in cases with metastatic lesions than in those with primary lesions. Although 28.6% patients were offered recommended treatment options, only 6.8% received the recommended treatments. This study highlights the differences in genetic alterations among the histological types of SGC, with comprehensive genomic profiling tests revealing lower drug accessibility. These findings could contribute to the development of personalized treatment for patients with SGC.

Salivary mucoepidermoid carcinoma: histological variants, grading systems, CRTC1/3-MAML2 fusions, and clinicopathological features.

AIMS: To investigate the histological diversity of salivary mucoepidermoid carcinoma (MEC), its clinicopathological features, and its associations with CRTC1/3-MAML2 fusions. METHODS AND RESULTS: Salivary MEC cases (n = 177) were examined for CRTC1/3-MAML2 fusions, histological variants were classified, and tumours were graded according to four different grading systems. Adverse histological features considered to be unusual in MEC were also investigated. Of the 177 MEC cases, 110 were positive for CRTC1/3-MAML2 fusions. The classical variant was the most frequent in the fusion-positive case group, the fusion-negative case group, and the total case group. The clear/oncocytic variant was the second most frequent in the fusion-positive and total case groups. Oncocytic, Warthin-like and spindle variants were seen in the fusion-positive case group only. Clear cell, sclerosing, mucinous and central variants were seen in both the fusion-positive case group and the fusion-negative case group. No case was classified as a ciliated variant, as a mucoacinar variant, or as a high-grade transformation. As compared with the classical variant, non-classical variants were characterised by frequent CRTC1/3-MAML2 fusions and a low clinical stage in all cases. Of the four histological features considered to be unusual in MEC, marked nuclear atypia, frequent mitoses (>10/10 high-power fields) and extensive necrosis were found independently of the fusion status, and were present in 3-5% of all cases. However, none of the cases showed overt keratinisation. On comparison, the Armed Forces Institute of Pathology and modified Healey grading systems downgraded tumours, the Brandwein system upgraded tumours, and the Memorial Sloan Kettering system provided a moderate means of assessment. CONCLUSION: Recognition of the histological diversity of MEC, its clinicopathological features and its associations with CRTC1/3-MAML2 fusions is helpful for an accurate diagnosis of this carcinoma.

Prognostic impact of CRTC1/3-MAML2 fusions in salivary gland mucoepidermoid carcinoma: A multiinstitutional retrospective study.

Mucoepidermoid carcinoma (MEC) is rare, but the most common primary malignancy of the salivary gland and not infrequent in young individuals. CRTC1/3-MAML2 fusions are frequently detected in MEC and are useful as a diagnostic biomarker. However, there has been debate as to whether the fusions have prognostic significance. In this study, we retrospectively collected 153 salivary gland MEC cases from 11 tertiary hospitals in Japan. As inclusion criteria, the MEC patients in this study had curative surgery as the initial treatment, received no preoperative treatment, and had no distant metastasis at the time of the initial surgery. The MEC diagnosis was validated by a central pathology review by five expert salivary gland pathologists. The CRTC1/3-MAML2 fusions were detected using FISH and RT-PCR. In 153 MEC cases, 90 (58.8%) were positive for CRTC1/3-MAML2 fusions. During the follow-up period, 28 (18.3%) patients showed tumor recurrence and 12 (7.8%) patients died. The presence of the fusions was associated with favorable tumor features. Of note, none of the fusion-positive patients died during the follow-up period. Statistical analysis showed that the presence of the fusions was a prognostic indicator of a better overall survival in the total and advanced-stage MEC cohorts, but not in the early-stage MEC cohort. In conclusion, CRTC1/3-MAML2 fusions are an excellent biomarker for favorable overall survival of patients with salivary gland MEC.

Next-generation sequencing assay in salivary gland cytology: A pilot study.

BACKGROUND: Preoperative diagnosis of salivary gland tumors (SGTs) by fine-needle aspiration (FNA) cytology is challenging. Next-generation sequencing (NGS)-based assays for somatic mutations have a great advantage in that a large number of genes can be analyzed simultaneously. Although NGS may have an enormous diagnostic potential in cytology, to our knowledge, the significance of NGS in SGT cytology remains to be clarified. METHODS: In this pilot study, we retrospectively examined 32 frozen SGT samples obtained at surgery (14 malignant and 18 benign). After the stored frozen tumor tissues were thawed, aspirate samples were obtained using 22-gauge needles and subjected to smear tumor samples and to DNA extraction for an NGS assay employing the Illumina AmpliSeq Cancer Hotspot Panel v2. The results were correlated to preoperative cytological diagnosis. RESULTS: The preoperative diagnoses obtained by FNA cytology included 23 negative lesions (no malignancy in 6 and benign tumor in 17) and nine positive lesions (suspicious for malignancy in 4 and malignancy in five), providing a sensitivity and a specificity of 9/14 (64%) and 18/18 (100%), respectively. The NGS assay detected somatic mutations in 10/14 malignant and 1/18 benign SGT cases, providing a sensitivity and a specificity of 71% and 94%, respectively. CONCLUSION: The NGS assay may be helpful for detecting the malignant potential in SGT cases and can be used as an ancillary test for SGT cytology.

Fluorescent periodic acid Schiff-like staining combined with standard cytologic staining of the same cytologic specimen may facilitate cytopathologic diagnosis.

BACKGROUND: Periodic acid Schiff (PAS) staining which detects glycogen and mucosubstances is frequently used as an ancillary method for an accurate cytopathologic diagnosis. Unfortunately, cytologic slides for PAS stain are not routinely prepared. Aqueous 7-amino-4-methylcoumarin (AMC) is colorless and transparent under bright field illumination but exhibits strong fluorescence under ultraviolet (UV) light and can be used as a Schiff reagent. We recently reported that combining [author: Please define (H&E) in the first occurrence if necessary.]H&E and AMC is useful for histopathologic diagnosis of various disease conditions. In this study, we investigated whether standard cytologic staining (Papanicolaou [Pap] and Giemsa) combined with AMC was useful for cytopathologic analysis. METHODS: Specimens of non-neoplastic human tissues and archived cytologic specimens of various disease conditions were stained with a combination of Pap and AMC (Pap/AMC) or Giemsa and AMC (Giemsa/AMC). RESULTS: The addition of AMC had no significant effect on Pap or Giemsa staining, and the cytomorphology under bright field microscopy was perfectly preserved. The AMC fluorescent signals observed under UV light were intense and the staining pattern was identical to that obtained by PAS staining. Diastase digestion differentiated glycogen from other AMC-positive elements. The efficacy of using Pap/AMC and Giemsa/AMC for archived cytologic specimens was demonstrated in several diseases including cases of endometrial carcinoma, adenoid cystic carcinoma, metastatic signet-ring cell carcinoma, candidiasis, and trichomoniasis. CONCLUSION: Pap/AMC and Giemsa/AMC are useful in aiding cytopathologic diagnosis especially when the information gained from PAS staining is critical and cytologic specimens for PAS are not available.

DHX37 Variant is One of Common Genetic Causes in Japanese Patients with Testicular Regression Syndrome / Partial Gonadal Dysgenesis without Müllerian Derivatives.

INTRODUCTION: The testicular regression syndrome (TRS) is a form of differences of sex development (DSD) in which the testes differentiate and function during early embryonic development, but subsequently regress. The clinical phenotype of TRS often overlaps with that of partial gonadal dysgenesis (PGD). Previous studies have demonstrated a causal association between TRS/PGD and heterozygous missense variants of DHX37. METHODS: We enrolled 11 Japanese 46,XY individuals (from 10 families) with TRS/PGD who exhibited undetected or hypoplastic testes, Müllerian duct regression, and low serum testosterone or anti-Müllerian hormone levels. The subjects underwent targeted sequencing of 36 known causative genes for DSD, PCR-based Sanger sequencing of DHX37, or whole exome sequencing. RESULTS: Previously described pathogenic variants or novel nonsense variants (SRY, NR5A1, and DMRT1) were observed in four out of 10 families. Additionally, we identified two heterozygous rare variants of DHX37 in four families: a previously reported pathogenic variant (c.923G>A, p.Arg308Gln) in three and a novel likely pathogenic variant (c.1882A>C, p.Thr628Pro) in one. The external genitalia of patients with the DHX37 variants varied from female-type to male-type without micropenis. Eighty percent of Japanese patients with TRS/PGD had monogenic disorders including DHX37 variant being the most commonly identified (40%). The external or internal genital phenotype of TRS/PGD overlaps between DHX37 variant carriers and others. CONCLUSIONS: DHX37 variant is one of common genetic causes in Japanese patients with TRS/PGD without Müllerian derivatives. Genetic test is helpful in detecting DHX37-related TRS/PGD, because of the phenotypic diversity of the external genitalia in this disorder.

Laparoscopic pancreas-preserving duodenectomy: Minimally invasive surgery for superficial nonampullary duodenal epithelial tumors.

No consensus exists regarding the optimal treatment for superficial nonampullary duodenal epithelial tumors. Herein, we describe a laparoscopic pancreas-preserving duodenectomy for the treatment of a 30-mm adenoma located in the third portion of the duodenum. The adenoma was located on the pancreatic side, further hindering safe endoscopic resection. Via laparoscopy, the jejunum was transected first. After releasing the third portion of the duodenum from the retroperitoneal space, the jejunum was pulled to the right side of the superior mesenteric artery and separated from the pancreas. Under endoscopic guidance, the duodenum was then transected and duodenojejunostomy performed intracorporeally. Laparoscopic pancreas-preserving duodenectomy can be considered minimally invasive, achieving tumor radicality while preserving organs and causing minimal destruction to the abdominal wall. In conclusion, although technically demanding, laparoscopic pancreas-preserving duodenectomy is a valuable treatment option for superficial nonampullary duodenal epithelial tumors.

Fluorodeoxyglucose-positron emission tomography as a potential alternative tool for functional diagnosis of glycogen storage disease type I.

A 43-year-old woman with genetically confirmed glycogen storage disease type Ib was suspected to have left breast cancer. Fluorodeoxyglucose-positron emission tomography showed high fluorodeoxyglucose accumulation in the whole liver as well as left mammary gland. We consider that high fluorodeoxyglucose accumulation in the liver of patients with glycogen storage disease type I is caused by impaired glucose-6-phosphate metabolism due to the congenital deficiency of glucose-6-phosphatase activities in hepatocytes. This study describes fluorodeoxyglucose-positron emission tomography as a potential alternative tool to diagnose glycogen storage disease type I functionally.

7-Amino-4-methylcoumarin as a fluorescent substitute for Schiff's reagent: a new method that can be combined with hemalum and eosin staining on the same tissue section.

An aqueous 7-amino-4-methylcoumarin (AMC) solution exhibits strong fluorescence under ultraviolet (UV) light and can be used as a Schiff reagent to visualize aldehydes. We investigated hemalum and eosin (H & E) and AMC staining for histological and pathological analysis. Sections of normal and lesioned human tissues were stained with combined H & E/AMC staining. After H & E/AMC staining, the H & E morphology was preserved under bright field microscopy. The AMC fluorescent signals observed under UV light were intense and the staining pattern was identical to that obtained by periodic acid-Schiff (PAS) staining. AMC staining of archived H & E sections also was successful. Diastase digestion differentiated glycogen from other AMC positive elements. Using H & E/AMC staining, mucus-rich adenocarcinoma cells, amebic trophozoites and fungal hyphae were visualized clearly under UV excitation. Using H & E/AMC staining, H & E and PAS-like histological imaging can be obtained using a single tissue section. H & E/AMC is useful for pathologic diagnosis especially when information from PAS staining is critical, the number of tissue sections is limited and/or the lesion in question is small.

Fibroblast growth factor 23 levels in cord and peripheral blood during early neonatal period as possible predictors of affected offspring of X-linked hypophosphatemic rickets: report of three female cases from two pedigrees.

OBJECTIVES: The role of serum fibroblast growth factor 23 (FGF23) level in early neonatal period on the diagnosis of X-linked hypophosphatemic rickets (XLH) remains unclear. CASE PRESENTATION: Two female patients from the first pedigree had an affected mother, and the other female from the second pedigree had an affected father. In all three cases, FGF23 levels were high in cord blood and peripheral blood at day 4-5. Additionally, the FGF23 levels considerably increased from birth to day 4-5. We identified a PHEX pathogenic variant and initiated treatment during infancy in each case. CONCLUSIONS: In neonates with a parent diagnosed as PHEX-associated XLH, FGF23 in cord blood and peripheral blood at day 4-5 may be useful markers for predicting the presence of XLH.

Potential benefit of rapid genetic testing for Pallister-Hall syndrome.

Pallister-Hall syndrome (PHS) is defined as a group of characteristic manifestations caused by a monoallelic GLI3 pathogenic variant. A two-month-old infant was referred to our institution because of undetermined sex. The infant had atypical genitalia with postaxial polysyndactyly, a hypothalamic mass, and an imperforate anus. We identified a known pathogenic variant of the GLI3 gene within one week and diagnosed the infant with PHS. The parents assigned the infant as male, considering the 46,XY karyotype, normal testosterone secretion, possible male identity, and the natural history of PHS. In infants with atypical genitalia and other malformations, such as polydactyly, a hypothalamic mass, or an imperforate anus, rapid GLI3 testing may provide information for planning lifelong management, including sex assignment.

Continuous glucose monitoring in an infant with panhypopituitarism having hypoglycemia on growth hormone therapy.

OBJECTIVES: The usefulness of continuous glucose monitoring (CGM) in infants with panhypopituitarism (PH) having hypoglycemia is yet to be explored. The potential adverse effects of growth hormone (GH) replacement therapy, such as hyperglycemia, cannot be comprehensively evaluated using the conventional measurement. CASE PRESENTATION: A 2-month-old infant with PH, including severe GH deficiency, had hypoglycemia despite frequent feeding. Glucose levels were monitored using CGM before and after GH replacement therapy. The proportion of time for hypoglycemia decreased from 4.9 to 0% (p<0.017). Hyperglycemia did not increase. The CGM method did not contribute to any adverse events requiring intervention. Our patient only experienced minor bleeding and no episode of cellulitis. CONCLUSIONS: CGM is useful in controlling glucose levels in infants with hypoglycemia and PH.

High-dose fludrocortisone therapy was transiently required in a female neonate with 21-hydroxylase deficiency.

For salt-wasting 21-hydroxylase deficiency (21OHD), fludrocortisone (FC) is usually supplemented at 0.05-0.2 mg/d dose. To date, no report has described 21OHD neonates requiring > 0.4 mg/d of FC. Our female 21OHD patient was lethargic and experienced weight loss with hyponatremia (133 mEq/L), hyperkalemia (6.5 mEq/L), and elevated active renin concentration (ARC, 1942.2 pg/mL) at 6 days of life. Hydrocortisone and FC replacement were initiated. FC dose was gradually increased to 0.4 mg/d at 21 days of life, but her hyperkalemia (6.4 mEq/L) and high ARC (372.3 pg/mL) persisted. We increased FC to 0.6 mg/d and used a low-potassium and high-sodium formula. Hyperkalemia subsequently improved. At 33 days of life, the ARC decreased to 0.6 pg/mL and FC dosage was gradually decreased. At 3 months of age, the low-potassium and high-sodium formula was discontinued, but the serum potassium level was normal and ARC remained low at 0.1 mg/d of FC. We speculated that severe mineralocorticoid resistance was the reason why her hyperkalemia persisted even with 0.4 mg/d of FC; however, the pathophysiology of transiently severe resistance to FC in this patient is unknown. In conclusion, 21OHD neonates may show severe salt-wasting that transiently require > 0.4 mg/d of FC.

Less-Invasive Diagnostic Approaches for Infants with Suspected Differences of Sex Development: A Case Report of a 297-g Neonate with Ambiguous Genitalia.

Less-invasive diagnostic approaches for low-birthweight preterm neonates with suspected differences of sex development have not been established. Herein, we describe our diagnostic approaches for a 297-g neonate with ambiguous genitalia. Using a fiberscope, the external genitalia were inspected in an incubator to minimize the risk of hypothermia and infection. Endotracheal aspirate, collected during routine care, was used for genetic testing to avoid anemia and vital signs fluctuations caused by peripheral blood sampling. Array comparative genomic hybridization indicated a 46,XY karyotype. No pathogenic variants of AR and SRD5A2 were found. Endocrinological data could not be evaluated owing to the absence of reference data. Identification and structural evaluation of the internal genitalia and gonads were difficult. On postnatal day 42, the parents assigned their baby's sex as male. Our less-invasive diagnostic approaches of inspection and genetic testing are useful for management, including sex assignment in extremely low-birthweight preterm neonates with ambiguous genitalia.

Pleomorphic adenoma: detection of PLAG1 rearrangement-positive tumor components using whole-slide fluorescence in situ hybridization.

Pleomorphic adenoma (PA) consists of heterogeneous histological architecture mixed with epithelioid and mesenchymal forms. Various types of epithelial or myoepithelial malignancies arise from PA, but sarcomas are extremely rare. A human androgen receptor gene (HUMARA) clonality assay has suggested that PA is clonal in nature. However, clonality of various tumor components of PA would be difficult to determine with this assay. In addition, the results obtained should be carefully interpreted. PLAG1 rearrangements are considered a good molecular marker for neoplasticity in PA. We aimed to clarify the neoplasticity of the various tumor components present in PA using whole-slide fluorescence in situ hybridization (FISH). Five PA cases positive for PLAG1 rearrangements were examined. Using an immunohistochemistry panel, cell components in PA were classified into eight cell types. To precisely localize PLAG1 rearrangement-positive cell components at the cellular level, sequential retrieval of whole-slide imaging (WSI) data of HE histology and FISH for PLAG1 rearrangement was carried out. PLAG1 rearrangements were detected in ductal cells, myoepithelial spindle cells, myoepithelial oncocytic cells, myoepithelial plasmacytoid cells, and mesenchymal chondroid cells, but not in mesenchymal lipid cells, mesenchymal fibrous cells, or vascular endothelial cells. Immunohistochemical PLAG1 expression was restricted to cell components harboring PLAG1 rearrangements.The results of the present study indicate that ductal and myoepithelial, chondroid cells are neoplastic but lipid, fibrous, and endothelial cells are not. PLAG1 immunohistochemistry is useful in discriminating neoplastic from non-neoplastic cell components. These findings may be important for elucidating tumorigenesis and the process of malignant transformation in PA.

Thymic Mucoepidermoid Carcinoma: A Clinicopathologic and Molecular Study.

Thymic mucoepidermoid carcinoma (MEC) is a rare tumor, and its characteristics remain to be clarified. Here we investigated 20 cases of thymic MEC to systematically characterize its clinical, histopathologic, and molecular features. The median age of the patients was 56 years (range, 19 to 80 y), there was a slight male predilection (3:2), and 44% of the patients were asymptomatic at diagnosis. The median tumor size was 6.8 cm in diameter, 55% were pT1 tumors, and 50% were TNM stage I tumors. When 4 tumor grading systems for salivary MEC (Armed Forces Institutes of Pathology, Brandwein, modified Healey, and the Memorial Sloan-Kettering) were employed, low-grade, intermediate-grade, and high-grade tumors accounted for 35% to 70%, 5% to 25%, and 25% to 50%, respectively. Many histologic variants were noted, and 70% of the cases were classified as nonclassic variants. MAML2 rearrangement was detected in 56% of cases, and the fusion partner was CRTC1 in all cases. CRTC1-MAML2 fusion was associated with lower pT classification and lower TNM stage. The overall survival rate of all patients was 69% and 43% at 5 and 10 years, respectively. Worse overall survival was associated with higher pT stage, higher TNM stage, residual tumors, greater tumor size, high-grade tumor histology (Armed Forces Institutes of Pathology and Memorial Sloan-Kettering, but not the other 2), and with the absence of CRTC1-MAML2 fusion. Of note, none of the patients with CRTC1-MAML2 fusion-positive tumors died during the follow-up. In conclusion, the clinicopathologic and molecular findings of thymic MEC presented here are expected to contribute to the management of this rare tumor.

Pulmonary Tumor Thrombotic Microangiopathy Secondary to Extramammary Paget's Disease: An Autopsy Case Report and Literature Review.

Pulmonary tumor thrombotic microangiopathy is a fatal disease secondary to some malignant tumors, such as gastric cancer, esophageal cancer, and pancreatic cancer. A 61-year-old man presented to our clinic with a red plaque with erosion on his scrotum and was diagnosed with extramammary Paget's disease. Seven years after the initial diagnosis, multiple bone metastases were discovered, and he was started on oral administration of tegafur/gimeracil/oteracil. Two years after beginning the oral drug administration, the patient complained of dyspnea. A chest CT scan showed ground-glass opacity. Pulmonary artery blood cytology revealed carcinoma cells. He was diagnosed with pulmonary tumor thrombotic microangiopathy. At 9 days after the diagnosis, he died of circulatory and respiratory failure. The autopsy revealed microscopic metastatic tumor emboli in multiple pulmonary vessels with fibrin thrombus, which confirmed the earlier cytologic diagnosis. Observations in our case were consistent with the typical pattern of this pathology in the lung with multiple metastases. Pulmonary tumor thrombotic microangiopathy with a primary disease of cutaneous malignancy is extremely rare. Here, we report a rare case of pulmonary tumor thrombotic microangiopathy secondary to extramammary Paget's disease with a literature review.