Branchioma is a rare benign neoplasm occurring in the lower neck. Occurrence of malignant neoplasms arising in branchioma is extremely rare. Here, we report a case of adenocarcinoma arising in branchioma. A 62-year-old man had a right supraclavicular mass measuring 7.5 cm in diameter. The tumor contained an adenocarcinoma component encapsulated in a benign branchioma component. The adenocarcinoma component consisted of high- and low-grade components, with the former accounting for 80% of the adenocarcinoma. The high-grade component was immunohistochemically characterized by diffuse strong p53 expression, while the low-grade component and branchioma component were negative for p53. Targeted sequencing analysis for the branchioma and adenocarcinoma components revealed that the adenocarcinoma component harbored pathogenic mutations in KRAS and TP53. No definitive oncogenic drivers were detected in the branchioma component. Based on these immunohistochemical and molecular findings, we suggest that the KRAS mutation contributed to the pathogenesis of the adenocarcinoma, and the TP53 mutation played a key role in the transition from low-grade to high-grade adenocarcinoma.
Parkinson's disease (PD) is the second most neurodegenerative disease after Alzheimer's disease. Accumulating knowledge points to the notion that abnormal aggregation of alpha-synuclein (αSyn) starts in the gut and ascends to the substantia nigra via the vagus nerve in about a half of PD patients. Epidemiological studies revealed that ulcerative colitis (UC) increases a risk for PD 1.3 to 1.8-folds. However, it remains unknown whether αSyn is abnormally aggregated in the enteric neurons in UC patients.We first inspected and optimized the immunostaining protocols with an anti-phosphorylated αSyn antibody, pSyn#64, using the brain and the gut of eight autopsied cases (five with PD and three without PD). Then, we examined abnormal αSyn aggregation in the enteric neurons in 23 and 18 colectomized patients with and without UC, respectively. Five or more sections were stained for αSyn in each of 87 and 25 paraffin- embedded blocks in patients with and without UC, respectively.Ten different protocols of epitope exposure appropriately stained aggregated αSyn in the brain, but only complete lack of epitope exposure stained aggregated αSyn in the colon with low background. Abnormal αSyn aggregates, which was confirmed by co-localization of p62, in the enteric neurons were detected in a single patient with UC but not in any patients without UC.Omission of epitope exposure enabled us to immunostain aggregated αSyn in the colon by pSyn#64 with low nonspecific staining, but the number of 23 UC patients was not high enough to discern whether abnormal αSyn aggregation in the colonic neural plexus was increased in UC or not.
Microsatellites are a set of repeating base sequences of one to several bases in a chromosome. In general, mismatch repair (MMR) proteins correct the base mismatches that occur during DNA replication. However, tumor cells with deficient MMR function accumulate genetic mutations and cause changes in the repeat counts in microsatellite sites, and such a status is referred to as microsatellite instability (MSI)-high status. According to recent research, MSI-high status is associated with responsiveness to therapies with immune checkpoint inhibitors [1].MSI status has been well described in various adult solid tumors; for instance, one of the largest studies has demonstrated that 1188 (9.9%) of 12,019 patients exhibited an MSI-high signature in various types of tumors [2]. However, there are no sufficient investigations on the MSI status in pediatric solid tumors, except those on limited tumor subtypes, including glioblastoma and medulloblastoma [3, 4]. Herein, we investigated the MSI status in pediatric patients with various solid tumors who died due to the tumor and also evaluated the potential of immune checkpoint inhibitors in refractory pediatric solid tumors.From April 2000 to May 2019, a total of 334 pediatric patients with solid tumors were admitted to the Nagoya University Hospital (Table 1 ). Although the majority of patients survived, 74 (22%) died, including 68 due to relapse or refractory tumor, 4 due to pulmonary complications after stem cell transplantations, and 2 due to infection after chemotherapies. We retrospectively analyzed the formalin-fixed paraffin-embedded tumor tissues of 40 (54%) of the 74 patients who died to assess the MSI status (Supplemental Table 1 , Supplemental Figure 1 ) using five multiplexed markers for determining the MSI-high phenotype (BAT-25, BAT-26, MONO-27, NR-21, and NR-24) (Supplemental methods ). Results demonstrated that 36 cases were microsatellite-stable and none of the patients had an MSI-high status; however, this observation could not be confirmed for the remaining four patients because of poor sample quality.These results indicate that MSI-high status is rare in pediatric patients with solid tumors who die of the disease. Therefore, surveillance of MSI status in children with refractory/relapsed solid tumors might have a limited role in predicting the responsiveness to immune checkpoint inhibitors.
Keratocystoma is a rare salivary gland lesion that has been reported primarily in children and young adults. Because of a scarcity of reported cases, very little is known about it, including its molecular underpinnings, biological potential, and histologic spectrum. Purported to be a benign neoplasm, keratocystoma bears a striking histologic resemblance to benign lesions like metaplastic Warthin tumor on one end of the spectrum and squamous cell carcinoma on the other end. This overlap can cause diagnostic confusion, and it raises questions about the boundaries and definition of keratocystoma as an entity. This study seeks to utilize molecular tools to evaluate the pathogenesis of keratocystoma as well as its relationship with its histologic mimics. On the basis of targeted RNA sequencing (RNA-seq) results on a sentinel case, RUNX2 break-apart fluorescence in situ hybridization (FISH) was successfully performed on 4 cases diagnosed as keratocystoma, as well as 13 cases originally diagnosed as tumors that morphologically resemble keratocystoma: 6 primary squamous cell carcinomas, 3 metaplastic/dysplastic Warthin tumors, 2 atypical squamous cysts, 1 proliferating trichilemmal tumor, and 1 cystadenoma. RNA-seq and/or reverse transcriptase-PCR were attempted on all FISH-positive cases. Seven cases were positive for RUNX2 rearrangement, including 3 of 4 tumors originally called keratocystoma, 2 of 2 called atypical squamous cyst, 1 of 1 called proliferating trichilemmal tumor, and 1 of 6 called squamous cell carcinoma. RNA-seq and/or reverse transcriptase-PCR identified IRF2BP2::RUNX2 in 6 of 7 cases; for the remaining case, the partner remains unknown. The cases positive for RUNX2 rearrangement arose in the parotid glands of 4 females and 3 males, ranging from 8 to 63 years old (mean, 25.4 years; median, 15 years). The RUNX2 -rearranged cases had a consistent histologic appearance: variably sized cysts lined by keratinizing squamous epithelium, plus scattered irregular squamous nests, with essentially no cellular atypia or mitotic activity. The background was fibrotic, often with patchy chronic inflammation and/or giant cell reaction. One case originally called squamous cell carcinoma was virtually identical to the other cases, except for a single focus of small nerve invasion. The FISH-negative case that was originally called keratocystoma had focal cuboidal and mucinous epithelium, which was not found in any FISH-positive cases. The tumors with RUNX2 rearrangement were all treated with surgery only, and for the 5 patients with follow-up, there were no recurrences or metastases (1 to 120 months), even for the case with perineural invasion. Our findings solidify that keratocystoma is a cystic neoplastic entity, one which appears to consistently harbor RUNX2 rearrangements, particularly IRF2BP2::RUNX2 . Having a diagnostic genetic marker now allows for a complete understanding of this rare tumor. They arise in the parotid gland and affect a wide age range. Keratocystoma has a consistent morphologic appearance, which includes large squamous-lined cysts that mimic benign processes like metaplastic Warthin tumor and also small, irregular nests that mimic squamous cell carcinoma. Indeed, RUNX2 analysis has considerable promise for resolving these differential diagnoses. Given that one RUNX2 -rearranged tumor had focal perineural invasion, it is unclear whether that finding is within the spectrum of keratocystoma or whether it could represent malignant transformation. Most important, all RUNX2 -rearranged cases behaved in a benign manner.
The anaplastic variant of diffuse large B‐cell lymphoma (A‐DLBCL) is morphologically defined but remains an enigmatic disease in its clinicopathologic distinctiveness. Here, we report two cases involving Japanese women aged 59 years, both with A‐DLBCL with the hallmark cell appearance and both indistinguishable from common and giant cell‐rich patterns, respectively, of anaplastic lymphoma kinase (ALK)‐positive anaplastic large cell lymphoma. Case 1 was immunohistochemically positive for CD20, CD79a and OCT‐2 but not for the other pan–B‐cell markers, CD30 and ALK. Case 2 showed CD20 and CD30 positivity for 50% and 20% of tumor cells in addition to strong expression of p53 and MYC. Both were positive for fascin without Epstein–Barr virus association. Our cases provide additional support for the earlier reports that A‐DLBCL exhibits clinicopathologic features distinct from ordinal diffuse large B‐cell lymphoma (DLBCL), and documented its broader morphologic diversity than previously recognized. They also shed light on the unique feature of absent expression of pan–B‐cell markers except for CD20 and CD79a, suggesting that A‐DLBCL may biologically mimic a gray zone or intermediate lymphoma between DLBCL and classic Hodgkin lymphoma.
In this issue of Cancer Cytopathology , Lee et al describe their experience with the Milan system in Singapore in a retrospective study over 10 years. Diagnosing lymphoid lesions and Warthin tumors is often a challenging issue in salivary gland fine needle aspiration cytology.
We propose a method to transfer a given pathology image stained by some immunostaining to a H&E stained one. When one construct a classifier that estimates the subtype of malignant lymphoma from a given H&E stained pathology image, one needs a set of training H&E stained whole slide images in which the tumor regions are annotated. The annotation is not easy and requires large human resources. Here, it is known that some immunostaining stains only some specific tumor cells and the tumor region detection from the immunostained images is straightforward. It means once you transfer the immunostained images to H&E stained ones, you can easily obtain a set of virtually H&E stained images with annotation of tumor regions. In this manuscript, we report on the proposed method and experimental results of stain transfer from CD20 stained images to H&E stained ones.
