Malignant phyllodes tumor with EGFR variant III mutation: A rare case report with immunohistochemical and genomic studies.

A female in her 60's presented with a left-sided breast mass. A core needle biopsy specimen showed diffuse proliferation of a round cell tumor, which was positive for vimentin, NKX2.2, BCOR, and focal CD99 on immunohistochemistry (IHC). No fusion genes of the Ewing family sarcomas were detected. With a tentative diagnosis of primary breast sarcoma (PBS), total mastectomy was performed after chemotherapy. The resected tissues showed proliferation of round or spindle-shaped tumor cells with a high nuclear-to-cytoplasmic ratio, exhibiting solid and fascicular arrangements but no epithelial component or organoid pattern. While IHC indicated no particular histological diagnosis, genomic examination revealed gene alterations in MED12 p.G44D, MLL2 (KMT2D) p.T1496fs*27, and EGFR variant III (vIII). Moreover, a retrospective IHC study showed overexpression of EGFRvIII. A malignant phyllodes tumor (PT) with extensive sarcomatous overgrowth was indicated as an integrative diagnosis. This is a rare case of a malignant PT harboring EGFRvIII. The present case provides an importance of accurate diagnosis and genomic analysis of rare breast tumors, as malignant PT and PBS are different in its treatment strategy and prognosis.

Low-grade Fibromyxoid Sarcoma With Massive Degeneration: A Case of Unusual Gross and Histological Features.

BACKGROUND: Low-grade fibromyxoid sarcoma (LGFMS) is a rare type of sarcoma which is observed in the soft tissue of proximal extremities, typically in young and middle-aged adults. It consists of a solid proliferation of bland spindle cells within collagenous and myxoid stroma. CASE REPORT: Herein, we report a case of LGFMS with massive degeneration and hyalinization. A 30-year-old man presented with a well-circumscribed mass measuring 15 cm in diameter in his left biceps femoris muscle. Marginal tumor resection was performed under the clinical diagnosis of an ancient schwannoma or chronic expanding hematoma (CEH). The resected tissue revealed a well-demarcated tumor mass with massive degeneration and hyalinization with focal calcification. Proliferation of spindle tumor cells with abundant collagenous stroma, which resembled the fibrous capsule of CEH, was observed exclusively in a small area of the periphery of the tumor. No nuclear palisading, myxoid stroma, or collagen rosettes were identified. Immunohistochemical analysis demonstrated that the spindle tumor cells expressed mucin 4 and epithelial membrane antigen. Reverse transcriptase-polymerase chain reaction analysis detected mRNA expression of fused in sarcoma::CAMP-responsive element binding protein 3-like protein 2 (FUS::CREB3L2) fusion gene. Thus, a final diagnosis of LGFMS with massive degeneration and FUS::CREB3L2 fusion was made. CONCLUSION: The recognition of massive degeneration and hyalinization as unusual features of LGFMS might be helpful to differentiate it from CEH and other benign spindle-cell tumors.

"Surface epithelial slackening" pattern in endometrioid carcinoma: A morphological feature for differentiating the POLE mutation-subtype from the no specific molecular profile subtype.

Endometrial cancers are classified into mismatch repair (MMR) deficient- (MMRd), p53 mutation- (p53mut), DNA polymerase epsilon (POLE) mutation (POLEmut), and no specific molecular profile (NSMP) subtypes according to The Cancer Genome Atlas (TCGA). The distinction between POLEmut and NSMP subtypes is made on the basis of molecular analysis because the specific histological and immunohistochemical features of these two subtypes are still unknown. In this study, we analyzed histological features by scoring the presence of a mucinous pool, giant cells, clear cells, keratinization, neutrophilic abscess, and surface proliferating pattern in 82 cases of endometrial cancers in which an integrative diagnosis was confirmed by immunohistochemistry and genomic profiles showing POLE mutations, tumor mutation burden, and microsatellite instability. In contrast to the hierarchical branching of micropapillary proliferation observed in serous carcinoma, POLEmut-subtype endometrioid carcinomas often showed a surface epithelial slackening (SES) pattern in the tumor cells facing the uterine surface. The POLEmut subtype exhibited higher scores for clear cells and SES patterns than the other three subtypes. The scores for giant cells, clear cells, and the SES pattern were significantly higher in the POLEmut subtype than in the NSMP subtype, suggesting that these morphometric parameters are useful for differentiating POLEmut- and NSMP-subtype endometrioid carcinomas, although genomic profiling is still necessary for a definite molecular diagnosis.

A case of acute liver failure due to aggressive natural killer-cell leukemia with a rapid course.

An 87-year-old man consulted a former doctor with a complaint of black stool and was admitted to hospital because of anemia and multiple gastric ulcers. The laboratory findings showed that his hepatobiliary enzyme levels and inflammatory response were elevated. Computed tomography showed hepatosplenomegaly and enlarged intra-abdominal lymph nodes. Two days later, he was transferred to our hospital due to deterioration of his liver function. Since he had low level of consciousness and his ammonia level was high, we diagnosed him with acute liver failure (ALF) with hepatic coma, and started on-line hemodiafiltration. As the cause of ALF, we suspected hepatic involvement of a hematologic tumor because of high lactate dehydrogenase and soluble interleukin-2 receptor levels and large abnormal lymphocyte-like cells in the peripheral blood. Because of his poor general condition, bone marrow and other histological examinations were difficult, and he died on the third day of hospitalization. Pathological autopsy showed marked hepatosplenomegaly and the proliferation of large abnormal lymphocyte-like cells in the bone marrow, liver, spleen, and lymph nodes. Immunostaining revealed aggressive natural killer-cell leukemia (ANKL).We herein report a rare case of the development of ALF with coma due to ANKL with a review of the relevant literature.

Deletion of Wnt10a Is Implicated in Hippocampal Neurodegeneration in Mice.

The hippocampus plays an important role in maintaining normal cognitive function and is closely associated with the neuropathogenesis of dementia. Wnt signaling is relevant to neuronal development and maturation, synaptic formation, and plasticity. The role of Wnt10a in hippocampus-associated cognition, however, is largely unclear. Here, we examined the morphological and functional alterations in the hippocampus of Wnt10a-knockout (Wnt10a-/-) mice. Neurobehavioral tests revealed that Wnt10a-/- mice exhibited spatial memory impairment and anxiety-like behavior. Immunostaining and Western blot findings showed that the protein expressions of ß-catenin, brain-derived neurotrophic factor, and doublecortin were significantly decreased and that the number of activated microglia increased, accompanied by amyloid-ß accumulation, synaptic dysfunction, and microglia-associated neuroinflammation in the hippocampi of Wnt10a-/- mice. Our findings revealed that the deletion of Wnt10a decreased neurogenesis, impaired synaptic function, and induced hippocampal neuroinflammation, eventually leading to hippocampal neurodegeneration and memory deficit, possibly through the ß-catenin signaling pathway, providing a novel insight into preventive approaches for hippocampus-dependent cognitive impairment.

Deficiency of Wnt10a causes female infertility via the ß-catenin/Cyp19a1 pathway in mice.

Wnt signaling is relevant for a wide range of biological processes, including reproductive function. The function of Wnt10a in female fertility, however, remains obscure. In the present study, we explored the structure and function of the female reproductive organs in Wnt10a knockout (KO) mice. The expression of ß-catenin signaling was significantly lower in the ovaries of the Wnt10a KO mice compared with wild-type (WT) mice. In addition, the estrous cycles were disrupted, ovarian follicles were diminished, and endometria were thinner, accompanied by lower serum estrogen levels, and higher testosterone and progesterone levels in Wnt10a KO mice. The expression of the ovarian cytochrome P450 family 19 subfamily A member 1 (Cyp19a1) was significantly lower in Wnt10a KO mice. We detected no significant changes in the levels of the gonadotropins between WT and KO mice. Together, our findings indicate that deficiency of Wnt10a causes female infertility through ß-catenin and Cyp19a1signaling pathways in mice.

Pelvic Carcinosarcoma Showing a Diverse Histology and Hierarchical Gene Mutation with a Common POLE Mutation to Endometrial Endometroid Carcinoma: A Case Report.

POLE mutation-type endometrial cancer is characterized by an extremely high tumor mutation burden. Most POLE mutation-type endometrial cancers are histologically endometrioid carcinomas, and POLE mutation-type carcinosarcomas are rare among endometrial cancers. We report a case of endometrial and pelvic cancer in a 53-year-old woman who was analyzed using next-generating sequencing. The endometrial lesion harbored a p.T457del POLE mutation with an elevated tumor mutation burden and low microsatellite instability. The pelvic lesion showed divergent histological features, consisting of high-grade endometrioid carcinoma, neuroendocrine carcinoma, and chondrosarcoma. In addition to the common POLE mutation detected in the endometrial lesion, the pelvic lesion in each element showed additional gene mutations in a hierarchical manner. Therefore, it is indicated that the p.T457del POLE mutation is a pathogenic mutation and may be related to POLE mutation-induced carcinogenesis and divergent morphogenesis in endometrial cancer.

Esophageal plexiform fibromyxoma: A case report with molecular analysis for MALAT1-GLI1 fusion.

Plexiform fibromyxoma (PFM) is a rare gastrointestinal tract tumor that develops in the stomach in most cases. Here, we report an extremely rare case of esophageal PFM. A female in her mid-30 s presented with difficulty in swallowing and breathing. Endoscopic examination revealed a submucosal tumor measuring approximately 45 × 50 mm in the upper thoracic esophagus. The biopsied specimen did not show definite histological evidence of gastrointestinal stromal tumors (GISTs). Since imatinib administration based on a clinical diagnosis of GIST did not show a therapeutic effect for tumor reduction, tumor resection was performed. The resected tumor exhibited proliferation of spindle tumor cells with abundant myxoid and vascular stroma separated by a muscular layer, indicating a plexiform arrangement. Immunohistochemical analysis demonstrated that the tumor cells diffusely expressed vimentin and alpha-smooth muscle actin, but not desmin, c-kit, DOG1, and CD34. MALAT1-GLI1 fusion was detected in formalin-fixed paraffin-embedded tissue using RT-PCR and Sanger sequencing. The results suggested that a fibromyxoid tumor can develop in the esophagus, showing an identical histology and MALAT1-GLI1 fusion to gastric PFM.

ATM immunohistochemistry as a potential marker for the differential diagnosis of no specific molecular profile subtype and POLE-mutation subtype endometrioid carcinoma.

Ancillary immunohistochemical tools can facilitate an integrated diagnosis of endometrial pathology. According to The Cancer Genome Atlas classification, endometrial cancers are of four molecular subtypes: mismatch repair (MMR)-deficient (MMR-d), p53 mutation (p53mut), DNA polymerase epsilon (POLE) mutation (POLEmut), and no specific molecular profile (NSMP). As the specific histological and immunohistochemical features of POLEmut and NSMP subtypes are unknown, these cancers are categorized based on molecular analysis. In this study, we analyzed POLEmut-subtype endometrioid carcinoma (EC) using a custom-made cancer gene panel and the Catalog of Somatic Mutations in Cancer (COSMIC) database, extracted a characteristic genome profile, and identified an immunohistochemical marker that could be used as a diagnostic tool. The results indicated that the POLEmut-subtype EC exhibited nonsense mutations in the ataxia telangiectasia mutated (ATM) gene and a subsequent loss of ATM expression, which was monitored through immunohistochemical analysis. Moreover, analyses using the COSMIC database indicated that POLEmut-subtype EC cases often harbored similar ATM nonsense mutations. These results suggest that ATM expression is a potential immunohistochemical marker for the differential diagnosis of POLEmut- and NSMP-subtype EC. DATA AVAILABILITY: The data supporting the findings of this study are available upon request from the corresponding author. The data are not publicly available because of privacy or ethical restrictions.

Adult Hepatocellular Carcinoma Coexisting with Extramedullary Hematopoiesis.

Extramedullary hematopoiesis (EMH) in adults usually occurs in the liver, spleen, and lymph nodes when bone marrow hematopoiesis fails. EMH has also been recognized in benign or malignant hepatic tumors, such as hepatoblastoma, hepatocellular adenoma, and vascular tumors. However, it is rarely encountered in hepatocellular carcinoma (HCC) in elderly adults, and the molecular mechanism of EMH in hepatic tumors remains unclear. We present a case of a 74-year-old man without any hematopoietic disorders and hepatitis viral infection who underwent hepatic resection for HCC. Histological examination revealed a well-differentiated HCC with trilineage hematopoiesis in the tumor and non-neoplastic liver. The coexistence of HCC and EMH in adult patients with no hematopoietic disorders is very rare and must be distinguished from poorly differentiated or dedifferentiated HCC and hepatoblastoma.

CD169 Expression on Lymph Node Macrophages Predicts in Patients With Gastric Cancer.

The induction of an anti-cancer immune responses is potentially associated with the efficacy of anti-cancer therapy. Recent studies have indicated that sinus macrophages in regional lymph nodes are involved in anti-cancer immune responses in the cancer microenvironment. In the present study, we investigated the correlation between lymphocyte infiltration in cancer tissues and macrophage activation in regional lymph nodes. We retrospectively identified 294 patients with gastric cancer who underwent surgery from 2008 to 2012. Using immunohistochemistry, we evaluated CD169-expression on CD68-positive macrophages, and the density of CD8-postive lymphocytes in tumor microenvironment. We statistically examined the correlation between CD169 and CD8 expression, and performed Cox regression analysis of potential prognostic factors, including CD169 and CD8 expression, for cancer-specific survival (CSS) in patients with total and advanced gastric cancer. CD169 overexpression in lymph node sinus macrophages (LySMs) was positively correlated to the density of CD8-positive lymphocytes in primary cancer tissues (R = 0.367, p < 0.001). A high density of CD8-positive T lymphocytes in the primary site and a high level of CD169 expression in LySMs were independently associated with greater CSS in patients with total and advanced gastric cancer (p < 0.05 for all). The expression on CD169 in LySMs is a predictor of a favorable clinical course in patients with gastric cancer, and might be useful for evaluating anti-cancer immune responses.

Rare histological subtype of invasive micropapillary carcinoma in the ampulla of Vater: A case report.

BACKGROUND: Carcinoma of the ampulla of Vater is an uncommon ampullo-pancreatobiliary neoplasm, and the most common histological type is adenocarcinoma with a tubular growth pattern. Invasive micropapillary carcinoma (IMPC) is an aggressive variant of adenocarcinoma in several organs that is associated with lymph node metastasis and poor prognosis. IMPC was first described as a histological subtype of breast cancer; however, IMPC of the ampulla of Vater is extremely rare, with only three articles reported in the English literature. CASE SUMMARY: We have reported a case of IMPC of the ampulla of Vater in an 80-year-old man. Microscopically, the surface area of the carcinoma was composed of tubulopapillary structures mimicking intra-ampullary papillary-tubular neoplasm, and the deep invasive front area exhibited a pattern of IMPC. The carcinoma showed lymphatic invasion and extensive lymph node metastasis. The immunohistochemical study revealed mixed intestinal and gastric/pan-creatobiliary phenotypes. CONCLUSION: This rare subtype tumor in the ampulla of Vater showed a histologically mixed phenotype and exhibited aggressive behavior.

Pulmonary infarction caused by sarcoidosis vascular involvement: A case report.

Sarcoidosis is a systemic granulomatous disease. In pulmonary sarcoidosis, granulomatous vascular involvement is a common feature that occurs in all types of vessels, including large elastic arteries to venules, but sarcoidosis complicated with pulmonary infarction has not been reported. We report a case of a 60 years old female, who was operated on a clinical diagnosis of lung cancer, and histological examination revealed a pulmonary infarction and sarcoidosis. In the pulmonary elastic arteries, granulomas infiltrated the adventitia and media, and caused elastic fiber collapse and destruction. Arterial occlusion by granulomas was observed in the edge of the infarcted area. It was considered that the arterial sarcoidosis granuloma involvement was the cause of pulmonary infarction. Sarcoidosis is a significant risk factor for cardiovascular events. However, pulmonary infarction is an extremely rare complication of sarcoidosis. Our case suggests that sarcoidosis may cause vascular events in the lungs.

Next-generation sequencing in residual liquid-based cytology specimens for cancer genome analysis.

BACKGROUND: Cancer genome profiling of cytology specimens using next-generation sequencing (NGS) requires adequate and good-quality DNA. Genomic examination of cytology samples was conventionally performed on cell block (CB) or smear specimens than on residual liquid-based cytology (LBC) specimens, which are high-quality DNA sources even after long-term storage. METHODS: We estimated tumor fractions of 37 residual LBC specimens, including 30 fine needle aspiration (FNA) samples from the thyroid (12 papillary thyroid carcinomas and two malignant lymphomas), lymph node (13 metastatic carcinomas and one malignant lymphoma), and breast cancer (one phyllodes tumor and one invasive ductal carcinoma), two pancreatic carcinoma samples, and five liquid (ascites, pleural effusion, and cerebrospinal fluid) samples. The DNA was extracted from all samples and subjected to NGS using a customized cancer gene panel comprising 28 cancer-related genes. RESULTS: NGS analysis revealed somatic mutations corresponding to pathological diagnosis with adequate variant allele frequency (VAF) in 24 LBC specimens, which had significantly higher tumor fraction (72.5% ± 4.9%). Ten cases, including the five fluid samples, had very small tumor fractions (7.5% ± 2.3%) to obtain sufficient VAF. Other two samples had high tumor fractions but showed very low VAF, indicating the presence of fusion genes. The remaining one sample yielded no DNA recovery. CONCLUSION: The residual LBC specimens collected by FNA from the thyroid gland and lymph node were verified to carry high tumor fraction and could serve as an alternate source for molecular testing to screen and diagnose cancers without the use of CB or smears.

Usefulness of magnifying endoscopy and endoscopic ultrasonography for the gastric involvement of follicular lymphoma.

A 61-year-old man received an esophagogastroduodenoscopy for further investigation of mesenteric lymphadenopathy. Esophagogastroduodenoscopy revealed swollen gastric folds and cobble stone mucosa in the gastric body. Magnifying endoscopy with narrow-band imaging showed branched abnormal vessels and the absence or destruction of gastric pits. Endoscopic ultrasonography (EUS) depicted homogeneously hypoechoic thickening of the submucosal layer where the mucosal changes were observed. The patient was diagnosed with follicular lymphoma by biopsy of these lesions. We should recognize that these endoscopic features are consistent with follicular lymphoma involving the stomach and that concurrent EUS is useful for diagnosis and identification of adequate biopsy sites.

Prevalence of Helicobacter pylori infection rate in heterotopic gastric mucosa in histological analysis of duodenal specimens from patients with duodenal ulcer.

Heterotopic gastric mucosa in the duodenal bulb is a rare congenital disorder with varied clinical presentations. The mechanism of formation of a duodenal ulcer is failure of balance of the attack factor and the defense factor, which is the same as the mechanism of formation of a gastric ulcer. However, the true etiology of the duodenal ulcer remains unknown. Gastric mucosa can secrete gastric juice which injures itself, but the duodenal mucosa does not contain cells secreting a digestive enzyme. We assume that duodenal ulcers are caused by the presence of heterotopic gastric mucosa that can secrete gastric acid. This study was designed to assess the prevalence and associations of heterotopic gastric mucosa in duodenal ulcers. The present study included 137 patients who underwent biopsy or resection of duodenal ulcer. We detected gastric foveolar metaplasia due to inflammation from a heterotopic gastric mucosa using immunohistochemical staining. Heterotopic gastric mucosa consists of foveolar epithelium (MUC5AC-positive) and fundic gland (H⁺K⁺ ATPase-positive parietal cells, pepsinogen I-positive chief cells and MUC6-positive mucous neck cells), whereas gastric metaplasia is composed of foveolar epithelium without fundic glands. These specimens were stained with toluidine blue for detection of Helicobacter pylori infection. Among the 137 patients with duodenal ulcer, 76 cases (55%) had heterotopic gastric mucosa in the obtained specimens, and Helicobacter pylori was found in 45 cases (59%,45/76) among those with heterotopic gastric mucosa. Our results suggest that heterotopic gastric mucosa was strongly associated with concurrent duodenal ulcer.

Verruciform Xanthoma of the Esophagus: Two Case Reports With Review of the Literature.

Verruciform xanthoma is a rare benign verrucopapillary lesion that develops in the oral mucosa and genital skin. Its development in the esophagus is extremely rare, with only 5 reported cases. We present 2 cases of verruciform xanthoma of the esophagus. Case 1 involved a 91-year-old woman, who had hypertension and chronic gastritis with Helicobacter pylori infection, with a 12-year history of a 10-mm white-yellow elevated lesion on the esophagus, 35 cm from the incisor teeth. Case 2 involved a 70-year-old man with fundic gland polyp, hyperlipidemia, and lung cancer, who had a 10-mm whitish granular/verrucoid lesion on the esophagus, 28 cm from the incisor teeth. Microscopically, these lesions show verrucous and papillomatous epithelial hyperplasia with neutrophilic intraepithelial exocytosis. The histological hallmark is the presence of numerous foamy histiocytes infiltrating the elongated squamous epithelial papillae. Although its etiology is unknown, irritation or trauma caused by radiotherapy has been suggested.

Depletion of WNT10A Prevents Tumor Growth by Suppressing Microvessels and Collagen Expression.

Background: We recently reported that WNT10A plays a pivotal role in wound healing by regulating collagen expression/synthesis, as the depletion of WNT10A dramatically delays skin ulcer formation. WNT signaling also has a close correlation with the cancer microenvironment and proliferation, since tumors are actually considered to be 'unhealing' or 'overhealing' wounds. To ascertain the in vivo regulatory functions of WNT10A in tumor growth, we examined the net effects of WNT10A depletion using Wnt10a-deficient mice (Wnt10a -/-). Methods and Results: We subjected C57BL/6J wild-type (WT) or Wnt10a -/- mice to murine melanoma B16-F10 cell transplantation. Wnt10a -/- mice showed a significantly smaller volume of transplanted melanoma as well as fewer microvessels and less collagen expression and more necrosis than WT mice. Conclusions: Taken together, our observations suggest that critical in vivo roles of Wnt10a-depleted anti-stromagenesis prevent tumor growth, in contrast with true wound healing/scarring.

Findings as a starting point to unravel the underlying mechanisms of in vivo interactions involving Wnt10a in bone, fat and muscle.

Wnt10a is a member of the WNT family. Although deficiency of this gene causes symptoms related to teeth, hair, nails, and skin, we recently demonstrated a new phenotype of Wnt10a knockout (KO) mice involving bone and fat. The in vivo effect of the Wnt10a gene on bone and fat is unclear, and the relationship between bone/fat and muscle in Wnt10a signaling is also interesting. We aimed to evaluate the tissue changes in Wnt10a KO mice compared to wild-type mice and show the findings as a starting point to unravel the underlying mechanisms of in vivo interactions involving Wnt10a in bone, fat and muscle. Trabecular bone loss in the lower limbs of Wnt10a mice and decreased bone mineralization were observed. The adipose tissue in bone marrow was also decreased, and adipocyte differentiation was reduced. The body fat mass in Wnt10a KO mice was decreased, and white adipocytes in subcutaneous fat were converted to beige adipocytes. The muscle weight of the lower limbs was not decreased despite trabecular bone loss, but Gdf8/myostatin expression was reduced in the subcutaneous fat and gastrocnemius muscles of Wnt10a KO mice. Thus, in vivo deletion of Wnt10a inhibited osteogenic activity, promoted beige adipogenesis of white adipocytes and maintained muscle mass. These results suggest that regulation of Gdf8 by Wnt10a may help maintain the muscle mass of Wnt10a KO mice. This study was the first to histologically evaluate the bone, fat and muscle phenotypes of Wnt10a KO mice. The results of this study, which were obtained by investigating the three tissues together, could influence the understanding of in vivo interactions involving the Wnt10a gene.