Mitochondrial Diabetes Mellitus With Mitochondrial DNA 3316G>A Mutation: A Unique Autopsy Case Presenting With Sepsis-Associated Cholestasis.

A 70-year-old female, diagnosed with mitochondrial diabetes mellitus (MDM) showing previously a point mutation at mitochondrial DNA 3316G>A, noticed urinary tract infection and diabetic gangrene of the foot with Gram-negative Bacteroides fragilis bacteremia, followed by aggressive jaundice with high serum level of direct bilirubin. She died two months after the symptom onset. At autopsy, multiple foci of bacteremia-induced hemorrhagic infarction were observed in the congestive bilateral lungs, whereas the cholestatic liver revealed no overt gross cholangiectasis. Microscopic findings characteristically showed many bile thrombi in the biliary canaliculi of hepatic lobules without any evidence of severe shock liver. Finally, we diagnosed it exclusively as sepsis-associated cholestasis due to the marked elevation of Gram-negative bacteria-derived endotoxins and inflammatory cytokines. We propose that these unique liver features in our MDM case might be one of the new clues to unveil its enigmatic etiology.

A Unique Surgical Case of Mixed Metaplastic Breast Carcinoma With Heterologous Mesenchymal Differentiation and Conventional Adenocarcinomatous Elements.

Metaplastic breast carcinoma (MBC) is very rare among all invasive breast carcinomas, accounting for less than 1.0% of them. MBCs are classified into five subtypes, including mixed MBC - where the mix might be multiple metaplastic elements or a mixture of epithelial and mesenchymal elements. Overall survival for mixed MBC tends to correlate with a significantly worse outcome. Therefore, an early accurate diagnosis and surgical treatment for mixed MBCs must allow for an improved quality of life and better prognosis. However, there have not been many recently published papers describing the detailed cytological features of mixed MBCs on fine-needle aspiration (FNA) specimens. A 60-year-old female presented with a history of a hard breast mass on the left lateral side, showing an ill-defined and marginally enhanced tumor nodule on magnetic resonance imaging. The cytologic specimens of FNA contained a large number of three-dimensional, cohesive and sheet-like clusters, or non-cohesive single cells, of highly atypical spindled sarcomatoid to oval epithelioid cells having hyperchromatic pleomorphic nuclei and mitotic figures, in a necrotic and hemorrhagic background. A small amount of osteoid matrix-like substance was rarely seen, associated with a very small number of osteoclast-like giant cells. We first interpreted it as an invasive breast carcinoma of high grade. A mastectomy was performed, and a gross examination of the neoplasm revealed a hemorrhagic solid tumor lesion with a gray-whitish cut surface, measuring approximately 35 × 24 × 21 mm in diameter. On a microscopic examination, the tumor was predominantly composed of the proliferation of highly atypical oval to spindled cells predominantly in a sarcomatous growth fashion with focal production of chondroid and osteoid matrix, peripherally coexisted with a smaller volume of conventional invasive breast carcinoma. Immunohistochemistry showed that the sarcomatous tumor cells were specifically positive for vimentin, α-smooth muscle actin, or epithelial membrane antigen. Therefore, we finally made a diagnosis of invasive mixed MBC with heterologous mesenchymal differentiation and conventional adenocarcinomatous elements. To the best of our knowledge, this would most recently be the first case report of mixed MBC with heterologous mesenchymal differentiation and conventional adenocarcinomatous elements, with a focus on its FNA cytomorphologic findings. We should be aware that owing to its characteristic cytological features, cytopathologists might be able to make a correct diagnosis of MBC, based on multiple and adequate samplings.

The combination of the low immunohistochemical expression of peroxiredoxin 4 and perilipin 2 predicts longer survival in pancreatic ductal adenocarcinoma with peroxiredoxin 4 possibly playing a main role.

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with poor prognosis. Therefore, indicators that can be used for the early prediction of the prognosis of PDAC are needed. Peroxiredoxin (PRDX) 4 is a secretion-type antioxidant enzyme located in the cytoplasmic endoplasmic reticulum. Recent studies have reported that it is closely related to the development and prognosis of many types of cancer. Perilipin (PLIN) 2 is a lipid droplet coating protein. The high expression of PLIN2 is known to be an indicator of some types of cancer and oxidative stress management. It is highly suggestive of the interplay between PRDX4 and PLIN2 to some degree. In this study, we collected 101 patients' clinical data and paraffin-embedded specimens with PDAC and analyzed them with immunohistochemical staining of PRDX4 and PLIN2. We found that the low expression of PRDX4 predicts longer survival and a better clinical condition in PDAC patients. Moreover, when the low expression of PRDX4 is combined with the low expression of PLIN2, the 3-year survival is significantly improved. Univariate and multivariate Cox proportional hazard analyses showed that the PRDX4 expression in PDAC was an independent prognostic factor for survival. Taken together, between PRDX4 and PLIN2, PRDX4 plays a main role in prognosis and has the potential to become a clinical prognostic indicator of PDAC.

Glioblastoma/high-grade glioma with a primitive neuronal component including rhabdoid differentiation that was difficult to diagnose: A case report.

Glioblastoma with a primitive neuronal component (GBM-PNC) is a rare subtype. In this case, GBM-PNC was difficult to diagnose conclusively because the specimen consisted of only a few high-grade glioma components. A 73-year-old woman presented with sensory aphasia and minor right-sided hemiplegia. Imaging revealed a neoplastic lesion with a maximum diameter of approximately 5 cm in the left frontal lobe for which surgery was performed. Histologically, most atypical cells were immature components with high nuclear-cytoplasmic ratios and immunopositive for neuroendocrine markers. Minor components of atypical glial cells were found at tumor margins. Rhabdoid cells were observed in undifferentiated components. Immunostaining was positive for glial fibrillary acidic protein (GFAP), nestin, and Olig2 in both undifferentiated and atypical glial cells. The major undifferentiated components showed significantly low GFAP, nestin, and Olig2 expression levels within the foci of the undifferentiated components, in contrast to the atypical glial component, neurofilaments and synaptophysin were immunopositive for undifferentiated components. Rhabdoid cells were immunopositive for myogenin, desmin, and HHF35, suggesting their differentiation into striated muscles. This was a particularly rare case because rhabdoid differentiation was observed in PNC.

The Junction Between the Peristaltic and Non-peristaltic Bowel (Shore Break) is Found in the Transition Zone in Hirschsprung's Disease.

BACKGROUND: The junction between the peristaltic and non-peristaltic bowel, which is named the "shore break" (SB), observed on endoscopy is thought to be the boundary between normal and abnormal motility in Hirschsprung's disease (HD). The transition zone (TZ), which is the histopathological border, does not have normal motility and should be resected. This study aimed to evaluate the histopathological findings of the SB and determine the association between the SB and TZ. METHODS: A retrospective review of surgical specimens of patients with HD who underwent preoperative SB marking was conducted. The TZ was defined if nerve hypertrophy, myenteric hypoganglionosis, or partial circumferential aganglionosis was detected. RESULTS: Ten patients (9 boys and 1 girl) were studied. The median age at surgery was 30 days. The median distance from the anal verge to the marked SB site was 14 cm. No patients manifested any obstructive symptoms resulting from a residual TZ bowel. In eight patients, nerve hypertrophy was identified at the proximal margin and at the SB. Myenteric hypoganglionosis was identified in three patients at the proximal margin and SB. Partial circumferential aganglionosis was identified at the SB in two patients. As a result, in all patients, the pull-through site and SB site had histopathological features indicating TZ. CONCLUSIONS: The SB is located in the TZ. Our results suggest that the proximal part of the TZ has normal motility and that functional border points may be present in the TZ. LEVEL OF EVIDENCE: IV.

A case of bone metastasis of hepatocellular carcinoma: Mallory hyaline bodies can lead to the correct cytological diagnosis.

Hepatocellular carcinoma (HCC) accounts for most primary tumors of the liver. Although bone metastasis does not occur in a high percentage of patients, bone metastasis is often found first, which leads to the diagnosis of HCC. In this report, we describe a case of bone metastasis from HCC in which bone lesions were detected incidentally, and in which a cytological diagnosis was difficult to make. The patient was a 78-year-old man with a history of renal dysfunction after orthopedic surgery. He underwent a thorough examination after a bone tumor was incidentally found on abdominal CT. Plasmacytoma was suspected. Fine needle aspiration cytology revealed irregular clusters of medium-to-large atypical epithelioid polygonal cells with relatively abundant eosinophilic, somewhat granular cytoplasm, and indistinct cell borders, which led to a diagnosis of malignancy. Histologically and immunohistochemically, the tumor was diagnosed as bone metastasis of HCC. Re-examination of the cytological specimen revealed characteristic Mallory hyaline bodies (MHBs). Immunohistochemistry using a cell transfer method revealed that they were positive for low molecular weight cytokeratin, Cam5.2, in a densely granular fashion. In this case, the cytological diagnosis of HCC was difficult to make due to the unclear cytoplasmic borders and absence of bile pigment. However, the identification of MHBs can potentially guide me to the correct cytological diagnosis.

Recurrent malignant phyllodes tumor of the breast: An extremely rare case of recurrence with only rhabdomyosarcoma components.

Rhabdomyosarcoma is a rare disease that typically occurs in children. Rhabdomyosarcoma seldom occurs in the breast, and its diagnosis and treatment have infrequently been reported. The present case is a rare one of a recurrent malignant phyllodes tumor of the breast with only rhabdomyosarcoma components. A 69-year-old woman received a diagnosis of borderline phyllodes tumor of the left breast and underwent partial mastectomy. During follow-up, a left breast mass was found 1 year and 8 months after the previous surgery. Based on examination findings, it was suspected to be recurrent phyllodes tumor, so total left mastectomy was performed in our hospital. After the surgery, immunostaining failed to determine the epithelial component which may be produced by the proliferative part of stromal cells of previous phyllodes tumors. However, we could not exclude the possibility that this was a new tumor. After comparing samples with specimens from the first operation, it was finally determined to be a malignant phyllodes tumor with a rhabdomyosarcoma component. Therefore, chemotherapy was given, and vincristine, actinomycin D, and cyclophosphamide therapy was introduced. At the same time, radiation therapy was planned. Among phyllodes tumors, cases involving rhabdomyosarcoma components are very rare, especially those where the recurrence morphology only shows the same rhabdomyosarcoma components. This was a rare case with unique characteristics and great reference value.

A surgical case of high-grade urothelial carcinoma of the renal pelvis complicated with giant hydronephrosis, giving rise to diagnostic difficulties on a cytological examination.

BACKGROUND: We report a surgical case of urothelial carcinoma of the renal pelvis, resulting in diagnostic difficulties on cytological examination. CASE PRESENTATION: A man in his late 70s underwent nephrectomy for giant hydronephrosis and renal cysts after nephrostomy and renal cyst puncture and drainage. On all cytological examinations performed before surgery, including nephrostomy urine, renal cyst fluid, catheterized bladder urine, and bladder washings, we were unable to make any conclusive diagnosis of malignancy. The pathological diagnosis of the surgical specimen concluded that this was a case of high-grade urothelial carcinoma of the renal pelvis with focal squamous differentiation (pT4). Liver and lung metastases were identified 3 months after surgery, and the patient died 2 months later. CONCLUSION: It was very difficult to make a conclusive diagnosis using cytological specimens because of the presence of a small number of atypical cells with severe degenerative changes. Since clinicians cannot predict the potential for malignancy on preoperative imaging findings, it is critical to consider the difficulties in clinically making a correct diagnosis of urothelial carcinoma of the upper urinary tract, especially in cases complicated with giant hydronephrosis.

Anterior mediastinal ectopic pancreatic cyst incidentally identified by pericarditis: a case report.

Ectopic pancreas often occurs in the gastrointestinal tract. However, the identification of a mediastinal ectopic pancreas is extremely rare. Herein, we report a case of ectopic pancreas of the anterior mediastinum, which was incidentally detected during treatment for pericarditis with widespread ST elevation on electrocardiogram. A 40-year-old woman complaining of chest pain was admitted with suspected pericarditis. A closer examination revealed a cystic mass in the anterior mediastinum, which was diagnosed as a pancreatic cyst of the anterior mediastinum on thoracoscopic tumor resection.

Nasal spindle cell tumor with rhabdomyoblastic features: A rare and diagnostically difficult case.

Nasal spindle cell rhabdomyosarcoma is very rare. The tumor is sometimes confused with other spindle cell tumors. We herein report a case of nasal spindle cell tumor in a 62-year-old woman. The patient first presented herself to a medical doctor's office after an episode of left epistaxis. An intranasal tumor was found and resected. The tumor was composed of spindle cells, and she was diagnosed with desmoid-type fibromatosis. Five years after the initial episode, an intranasal tumor was found again. The tumor showed a fascicular growth pattern with high cellularity and was predominantly composed of spindle cells. Scattered eosinophilic rhabdomyoblasts were also observed. She was diagnosed with spindle cell rhabdomyosarcoma. This is a unique case report not only because nasal spindle cell rhabdomyosarcoma is very rare but also because the tumor was initially diagnosed as desmoid-type fibromatosis. It is important to consider spindle cell rhabdomyosarcoma as a differential diagnosis of nasal spindle cell tumors.

Early-stage multi-differentiated gastric carcinosarcoma and post-resection local recurrence: a case report.

BACKGROUND: Carcinosarcoma is a rare neoplasm with a poor prognosis that is most often discovered at an advanced stage; a gastric carcinosarcoma is even rarer than carcinosarcomas originating in other organs, such as the uterus. We report our experience with an early-stage multi-differentiated gastric carcinosarcoma. CASE PRESENTATION: A 68-year-old male patient presented with anemia, and his fecal occult blood test was positive. An endoscopic examination was conducted which revealed a hemorrhagic, irregular, protruding lesion in the stomach. The lesion was diagnosed as an adenocarcinoma by histopathological examination of the biopsy specimen, and a segmental gastrectomy was performed. A 41 × 29 × 18 mm3 protruding lesion was observed in the resection specimen, and histologically confirmed to be a gastric carcinosarcoma with mixed adenocarcinomatous and sarcomatous composition. Tumor invasion was limited to the submucosa. Besides the adenocarcinomatous portion, neuroendocrine differentiation and AFP-positive gastric carcinoma were present in the carcinomatous portion of the tumor; in the sarcomatous portion, chondrosarcomatous, leiomyosarcomatous, and rhabdomyosarcomatous components were observed in addition to the undifferentiated sarcomatous component. Furthermore, the tumor included SALL4-positive germ cell-like cells. Despite early-stage detection, the cancer recurred locally 14 months after tumor resection, which necessitated a total gastrectomy. At the 2-month follow-up after the total gastrectomy, the patient was alive. This patient had developed an esophageal squamous cell carcinoma and primary lung adenosquamous carcinoma, both of which were resected. CONCLUSIONS: Few cases of early-stage gastric carcinosarcoma have been reported, but there are no reports of recurrence to date. Local recurrence as in this patient, and even in early-stage cases, requires cautious surveillance to check for post-resection recurrence and metastasis. The etiopathogenesis of carcinosarcoma has not yet been elucidated; however, in the present case, despite the tumor's relatively small size, it exhibited various types of differentiation in both the carcinomatous and sarcomatous components and a proliferative germ cell-like portion, which suggests that the monoclonal origin hypothesis may be a valid theory for the carcinosarcoma.

Durvalumab-induced Immune-related Hepatitis in a Patient with Non-small Cell Lung Cancer.

We herein report the case of a 79-year-old patient with unresectable stage III non-small cell lung cancer who developed immune-related hepatitis caused by durvalumab administration. Durvalumab was administered at 10 mg/kg every two weeks after the treatment with carboplatin (AUC2), paclitaxel (35 mg/m2), and 60 Gy radiation. At the day 208 in which the 14th durvalumab administration was scheduled, the patient was urgently hospitalized due to CTCAE Grade 4 hepatic dysfunction detected during the an outpatient blood sampling test. He was diagnosed with immune-related hepatitis and started on methylprednisolone 60 mg/day. After 51 days, his liver dysfunction improved and he was discharged.

Rhabdomyosarcoma arising from retroperitoneal teratoma in an infantile neurofibromatosis type 1 patient.

We herein report the case of a 2-year-old girl with neurofibromatosis type 1 (NF1), who presented with a 12-cm mass in the right retroperitoneum and underwent tumor resection. Histologically, the tumor was composed of two distinct components: one was teratoma, showing mature morphology; and the other was embryonal rhabdomyosarcoma. An interphase fluorescence in situ hybridization (FISH) analysis of the rhabdomyosarcoma component revealed the absence of isochromosome 12p. Although it is well known that rhabdomyosarcoma occurs in infantile NF1, and that rhabdomyosarcoma can arise from teratoma as a somatic-type malignancy, to the best of our knowledge, this is the first case of an infantile NF1 patient, who developed rhabdomyosarcoma within a retroperitoneal teratoma. The absence of chromosome 12p alteration suggests a possibility that the rhabdomyosarcoma occurred due to the NF1 background, not as a somatic-type malignancy of germ cell tumor.

The potential role of follicular helper T cells in idiopathic multicentric Castleman disease with and without TAFRO syndrome.

Idiopathic multicentric Castleman disease (iMCD) is a systemic inflammatory disease of unknown etiology caused by hypercytokinemia. Recently, TAFRO (thrombocytopenia, anasarca, fever, renal failure or reticulin fibrosis, and organomegaly) syndrome has been reported, which shows similar histopathological findings to iMCD and factors associated with a poor prognosis. iMCD shows no plasma cell infiltration in the germinal center (GC), but CD38-positive (CD38+)-plasma cells are observed in the interfollicular area. Our previous report revealed that atrophic change of GC, glomeruloid vascular proliferation, and abnormal proliferation of follicular dendritic cells are more prominent in iMCD with TAFRO (TAFRO+) in comparison to iMCD without TAFRO (TAFRO-). In addition, the numbers of CD38+ and immunoglobulin G4-positive (IgG4+) plasma cells were decreased in the interfollicular area. The roles of T follicular helper cells (Tfh) are well-known to assist B-cell proliferation, maturation, and differentiation．It maintains the formation of GC and is also related in the class switching of IgG isotypes, including IgG4. Thus, we immunohistochemically examined the number of Tfh in GCs in both TAFRO- and TAFRO+ iMCD. The number of Tfh was significantly decreased in TAFRO- iMCD (n = 9) and was further decreased in TAFRO+ iMCD (n = 18) in comparison to non-specific lymphadenopathy (n = 6) and IgG4-related disease (n = 4). These results suggest that decreased Tfh may be one etiology of iMCD.

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.

Possibly Late-Onset Arrhythmogenic Right Ventricular Cardiomyopathy: Unique Triglyceride Deposition by Analysis of Lipid Contents.

We presented an unusual arrhythmogenic right ventricular cardiomyopathy (ARVC) case of a late-60s elderly man's death, due to severe pericardial/pleural effusion and ascites, and arrhythmic events, with unique pathological features. The hypertrophic heart grossly displayed yellowish to yellow-whitish predominantly in the variably thinned wall of the dilated right ventricle. Microscopic findings showed diffuse fatty/fibrofatty replacement in not only the right but left ventricular myocardium, together with an outer lymphoplasmacytic infiltrate. According to the lipid contents analysis, the triglyceride content, but not the cholesterol content, in our patient's right and left ventricular cardiac muscle was much higher than that in the control subject. We propose that this unique triglyceride deposition in our possibly late-onset ARVC case might be one of new clues to understand its enigmatic cause. Further prospective studies are needed to validate the presence and significance of a greater volume of triglyceride deposit, after collecting and investigating a larger number of early and late-onset ARVC cases examined.

An extranodal histopathological analysis of idiopathic multicentric Castleman disease with and without TAFRO syndrome.

Thrombocytopenia, anasarca, fever, renal failure or reticulin fibrosis, and organomegaly (TAFRO) syndrome, a poor prognostic clinical condition showing similar histopathological findings to idiopathic multicentric Castleman disease (iMCD), has been reported in Japan. In our previous report, a clinicopathological analysis was performed on 70 nodal cases of iMCD with/without TAFRO. iMCD is classified into three types based on histopathology: (i) plasmacytic (PC), (ii) mixed, and (iii) hypervascular (hyperV). In this report, extranodal histopathological changes of iMCD with/without TAFRO were analyzed. Regarding the kidney pathology, we observed the proliferation of mesangial cells with positive staining of interleukin-6 (IL-6), consistent with membranoproliferative glomerulonephritis, in two cases of iMCD with TAFRO. The number of megakaryocytes per high-powered fields was not significantly different between iMCD cases with and without TAFRO. In conclusion, extranodal lesions of iMCD with/without TAFRO showed various interesting histopathological findings. These lesions may therefore be related to the clinical condition of TAFRO. Obtaining further knowledge about TAFRO will require the observation of nodal as well as extranodal lesions.

An autopsy case of peripheral T cell lymphoma occurring in a postpartum woman: a unique case suggesting changes in the immunocharacteristics of lymphoma cells before and after delivery.

BACKGROUND: The occurrence of malignant lymphoma after delivery is an extremely rare event. Although several cases of Hodgkin lymphoma and B cell lymphoma and a few cases of peripheral T cell lymphoma (PTCL) after delivery have been reported, there are no report of autopsy cases of PTCL in the puerperal period. CASE PRESENTATION: A 32-year-old Japanese woman with a past medical history of atopic dermatitis and bronchial asthma presented with generalized eruptions four days after the delivery of her first child; generalized skin induration and lymphadenopathy subsequently emerged. A skin biopsy specimen showed the diffuse proliferation of atypical lymphoid cells that were immunohistochemically-positive for CD4 but negative for CD8. She was diagnosed as PTCL, not otherwise specified (PTCL, NOS). She died one year and three months after the onset of symptoms. At autopsy, the systemic infiltration of lymphoma cells into the whole body was observed. Unexpectedly, these lymphoma cells were immuno-reactive with CD8 but not with CD4. CONCLUSION: The occurrence and development of PTCL after delivery with the shift from CD4 positivity to CD8 positivity may be associated with not only the selection of resistant subclone as a result of chemotherapy but also the changes of immune status before and after delivery.