Eisuke Shiba

CAMTA1 is a useful immunohistochemical marker for diagnosing epithelioid haemangioendothelioma

The diagnosis of epithelioid haemangioendothelioma (EHE) is usually straightforward, based on characteristic histological features. However, it is sometimes difficult to differentiate EHE from a variety of other tumours with epithelioid morphology. The WW domain‐containing transcription regulator 1–calmodulin‐binding transcription activator 1 (WWTR1–CAMTA1) fusion gene, resulting in the overexpression of CAMTA1, is demonstrated in approximately 90% of EHEs, and the yes‐associated protein 1–transcription factor E3 (YAP1–TFE3) fusion gene, associated with the strong and diffuse nuclear expression of TFE3, is present in another small subset of EHEs. The aim of our study was to examine CAMTA1 expression in EHEs and a variety of other tumours to evaluate its diagnostic utility, and to analyse TFE3 expression status in EHEs.

Lanthanum deposition in the gastrointestinal mucosa and regional lymph nodes in dialysis patients: Analysis of surgically excised specimens and review of the literature.

Lanthanum carbonate (LC) is one of the most potent phosphate binders currently used to reduce serum phosphate levels in dialysis patients with end-stage renal disease (ESRD). LC forms insoluble complexes with dietary phosphate that pass through the gastrointestinal (GI) tract with little absorption. GI lesions due to lanthanum deposition in biopsy specimens or those in endoscopic submucosal dissection (ESD) in dialysis patients have been recently identified. Here, we describe more detailed histopathological findings in the gastroduodenal mucosa and regional lymph nodes in three patients with gastric cancer. Three patients with ESRD, two elderly women and one man, underwent dialysis and were treated with LC for 3-36 months. The patients underwent laparoscopic distal gastrectomy and lymph node dissection due to gastric cancer. Many subepithelial histiocyte aggregates or small foreign body granulomas, which contained gray or brown pigments or crystal-like structures, were mostly present in non-neoplastic areas of the upper GI. Lanthanum accumulation was noted in the duodenal mucosa and the antral and body mucosae of the gastric lesser curvature. Lanthanum was also deposited in the regional lymph nodes of the three patients. Electron microscopy with energy dispersive X-ray spectroscopy confirmed lanthanum and phosphorus deposits in histiocytes. Long-term prognosis of patients and the excretion or the metabolic pathway of accumulated lanthanum remain unclear.

Immunohistochemical and molecular detection of the expression of FGF23 in phosphaturic mesenchymal tumors including the non-phosphaturic variant

BackgroundPhosphaturic mesenchymal tumors (PMTs) are rare neoplasms that are often associated with tumor-induced osteomalacia (TIO) due to excessive serum levels of fibroblast growth factor 23 (FGF23). PMTs share overlapping histologic features with other types of tumors; thus, accurate pathological diagnosis may be challenging. We performed an immunohistochemical examination of FGF23 expression in PMTs and other types of tumors, together with pertinent molecular analyses.MethodsSeven PMTs (5 with TIO and 2 without TIO) and 46 other types of bone and soft tissue tumors were retrieved, and immunohistochemistry was performed using a commercially available anti-FGF23 antibody. In addition, FGF23 mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR), using RNA extracted from formalin-fixed, paraffin-embedded tissues.ResultsImmunohistochemical analysis of FGF23 expression showed distinct, punctate staining in the cytoplasm in 5 PMTs with TIO, whereas FGF23 expression was negative in the 2 PMTs without TIO and the other 46 tumors. FGF23 mRNA expression was detected in all 4 PMTs examined, as well as in 1 chondromyxoid fibroma and 1 myxoid liposarcoma. The real-time RT-PCR data showed that the relative expression levels of the FGF23 mRNA tended to be higher in PMTs with TIO than in PMTs without TIO, or in the chondromyxoid fibroma specimen.ConclusionsOur data suggested that the feasibility of immunohistochemical detection of FGF23 may depend on the level of secreted FGF23 from tumor cells. Thus, immunohistochemistry for FGF23 is an useful diagnostic adjunct for PMT, although its utility appears to be limited in cases without TIO.

Clinicopathologic Diversity of Undifferentiated Sarcoma With : Analysis of 11 Cases With a Reappraisal of the Utility of Immunohistochemistry for Bcor and Ccnb3 bcor-ccnb3 : Analysis of 11 Cases With a Reappraisal of the Utility of Immunohistochemistry for Bcor and Ccnb3 Fusion: Analysis of 11 Cases With a Reappraisal of the Utility of Immunohistochemistry for Bcor and Ccnb3

Undifferentiated sarcoma harboring the BCOR-CCNB3 fusion is characterized by its predilection to affect skeletons of adolescent males, cellular small round/spindle cell morphology, and CCNB3 immunoreactivity. We analyzed 11 cases of BCOR-CCNB3 sarcoma, 10 of which were identified in a reverse transcription-polymerase chain reaction–based screen of 85 patient samples recorded in our database as unclassified small round or spindle cell sarcomas. BCOR rearrangements were confirmed by fluorescence in situ hybridization in 8 tumors. All patients were males aged between 6 and 31 years. In addition to 5 tumors in soft tissue and 4 in the axial or appendicular skeletons, which are typical locations, a tumor was located in the paranasal sinus and another in the lung. Microscopically, the tumors comprised proliferating atypical spindle and/or small round cells with diverse morphologic features such as small concentric whorls, myxoid stroma, a hemangiopericytomatous appearance, and/or hyalinized collagen resembling a solitary fibrous tumor, and angiomatous or slit-like spaces containing extravasated erythrocytes. Tumor cells were immunoreactive to CCNB3 (9/11), BCOR (10/10), TLE1 (6/10), bcl-2 (9/11), CD99 (8/10), CD56 (8/10), c-kit (4/10), and cyclin D1 (10/10). In an immunohistochemical analysis of an additional 412 small round or spindle cell tumors, CCNB3 was detected in 6 (1.5%) and BCOR in 18 (4.4%). Our analysis highlights the varying clinicopathologic features of this tumor, which partially overlap with other small round or spindle cell tumors, including solitary fibrous tumor and vascular tumors. Because CCNB3 and BCOR immunohistochemistry lacks adequate sensitivity and specificity, a molecular genetic approach remains essential for diagnosis.

Prognostic significance of WNT signaling in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal human malignancies and is associated with a variety of molecular abnormalities. Although WNT signaling through its canonical/non-canonical pathways is one of the major factors involved in oncogenesis or progression of PDA, the prognostic significance of WNT signaling still remains poorly investigated. In this study, the status of the WNT signaling pathways was immunohistochemically analyzed in 101 PDAs, and its potential association with patient postoperative survival was assessed. Nuclear expression of beta-catenin, a hallmark of the activated canonical pathway, was identified in 59 cases, and was associated with reduced survival compared to the patients lacking nuclear beta-catenin expression (P = 0.002). In contrast, activation of the non-canonical pathway (25 cases), as indicated by co-expression of WNT2/5a and nuclear NFATc1, was not correlated with reduced survival (P = 0.268). Co-activation of both pathways (16 cases) was associated with worse prognosis in comparison with cases with an activated non-canonical pathway (P = 0.034). In addition, nuclear beta-catenin expression was an independent unfavorable prognostic factor (P = 0.006). Our data indicate that activated WNT signaling through its canonical pathway has a significantly negative effect on the clinical course of PDA, and the canonical WNT pathway should be considered as a future therapeutic target for PDA.

Squamous cell carcinoma arising from an epidermal cyst in the thumb

Highlights • Squamous cell carcinoma arising from an epidermal cyst is rare.• The most frequently affected region is the head and neck. In contrast, involvement of the fingers is extremely rare.• The clinical symptoms of squamous cell carcinoma arising from an epidermal cyst can mimic those of an infected epidermal cyst.• The current report facilitates awareness of such disease.

Presacral myelolipoma as a possible parasymptom of cancer: A case report:

Presacral myelolipomas are rare, benign, asymptomatic tumors composed of mature adipose tissue and hematopoietic elements. Presacral myelolipomas can occur in patients with a medical history of malignancy, steroid use, and/or endocrine disorders including diabetes mellitus. A 65-year-old man with no specific medical history experienced temporal abdominal pain without bowel symptoms that lasted a few hours. By the time he visited a hospital, the pain had diminished. Computed tomography failed to detect any abnormality in the abdominal or pelvic organs that would have caused the abdominal pain but revealed a lesion 4 cm in diameter in the frontal sacrum. Magnetic resonance imaging showed that the lesion contained fat elements with a high signal intensity on T1- and T2-weighted images, which was decreased on fat-suppression T2-weighted images. Computed tomography–guided biopsy and imaging allowed a diagnosis of presacral myelolipoma. After 3 months, hematochezia was observed, and follow-up examination revealed rectal carcinoma with multiple lung metastases. He died due to spread of the cancer despite chemotherapy, 6 months after the cancer was found. Considering the possible association between presacral myelolipoma and cancer, presacral myelolipoma might be a cancer parasymptom. Checking for possible malignancy may therefore be warranted in patients with presacral myelolipoma, especially in those without diabetes mellitus.

Inhibition of WNT/β-catenin signaling under serum starvation and hypoxia induces adipocytic transdifferentiation in human leiomyoma cells

Fatty metamorphosis is an uncommon alteration in uterine leiomyoma (i.e., lipoleiomyoma), and the pathogenetic mechanisms underlying this phenomenon remain poorly understood. Because a conditional deletion of β-catenin, a major transducer of the canonical Wingless/integrated (WNT) pathway, in the developing mouse uterus can induce adipogenesis in the myometrium, it is hypothesized that inhibition of the WNT/β-catenin signaling may be also involved in the development of fat cells within uterine leiomyoma. In the current study, which was performed to address this point, intracytoplasmic lipid droplets were detectable in cultured human leiomyoma cells by treatment with a potent tankyrase inhibitor, XAV939, which antagonizes β-catenin, in a serum-starved culture medium without additional adipogenesis-inducing agents or supplements, and showed increasing accumulation in a time-dependent manner. In addition, the induction of fat cells was greatly enhanced under hypoxic conditions (i.e., 2.5% O2)—recapitulating the local in vivo situation of uterine leiomyoma—in comparison to that under normoxic conditions (i.e., 21% O2). The marker genes of differentiated fat cells such as ADIPOQ and PLIN were highly expressed in leiomyoma cells that were treated with XAV939 under hypoxia and serum starvation, whereas the immunohistochemical expression of desmin—a cytoskeletal protein representing smooth muscle differentiation—was downregulated, which appears in line with the switch in differentiation. The results of our study suggest that the inhibition of canonical WNT/β-catenin signaling under the stress due to hypoxia and serum starvation can initiate adipocytic transdifferentiation or metaplasia in human uterine leiomyoma cells, which is potentially related to the development of lipoleiomyoma.

Florid reactive periostitis of the metacarpal bone: a case of resolution without resection

Florid reactive periostitis is a benign bone lesion characterized by a mixture of bone and fibro-connective tissue without atypia. Most patients with florid reactive periostitis are aged between 20 and 40 years, and women are more commonly affected than men. Florid reactive periostitis usually occurs in tubular bones of the hands and feet and most often in the phalanges (Riaz et al., 1996; Tomori et al., 2016). A 34-year-old, right-handed woman presented with a 4-week history of pain and an enlarging soft-tissue mass in the right hand, without a history of trauma. She was a housewife who did not participate in any regular sporting activity. There was a hard tender, 2 0.8 0.5 cm mass palpable along the ulnar side of the fifth metacarpal. The overlying skin showed no signs of redness and appeared normal. The lesion was fixed to the metacarpal bone but not associated with the tendon. The range of motion of the metacarpophalangeal joint was slightly restricted as a result of pain and swelling. Plain radiographs revealed a soft-tissue mass with erosion of the underlying bone of the fifth metacarpal without apparent periosteal bone formation. A working diagnosis of florid reactive periostitis was based on both plain radiographs and magnetic resonance images, which suggested the presence of a periosteal lesion. A biopsy was not performed initially; rather, a conservative approach involving regular observation without resection of the lesion was adopted. Seven months after the initial diagnosis, the soft-tissue lesion had enlarged and ossified (Figures 1(a) and (b)). A needle biopsy to exclude malignancy confirmed the initial working diagnosis of florid reactive periostitis. The pain disappeared 1 year after the original diagnosis. At the 2-year follow-up, a periosteal reaction in conjunction with ossification had become apparent on plain radiographs. No additional changes

Sclerosing Mucoepidermoid Carcinoma in the Parotid Gland With CRTC1-MAML2 Fusion: A Case Report:

In this article, we report a case of sclerosing mucoepidermoid carcinoma (MEC) arising in the parotid gland, with CRTC1-MAML2 gene fusion. A 73-year-old woman with a mass in the right parotid region was referred to our hospital. Radiological imaging tests revealed a well-defined mass, measuring 25 mm in diameter, with foci of calcification in the deep lobe of the parotid gland, extending to the parapharyngeal space. Microscopically, the tumor was composed of a proliferation of atypical glandular epithelial cells having intracytoplasmic mucin, squamoid cells, and intermediate cells arranged in nests embedded in a fibrosclerotic stroma, associated with a dense chronic inflammatory infiltrate containing immunoglobulin G4-immunoreactive plasma cells. Reverse transcription-polymerase chain reaction analysis using a formalin-fixed, paraffin-embedded tumor tissue specimen revealed the CRTC1-MAML2 fusion gene transcript. This is the first report of sclerosing MEC with the detection of the MEC-associated fusion gene, reinforcing a common genetic association between MEC and sclerosing MEC.