Distinct Clinicopathologic Features and Possible Pathogenesis of Localized ALK-positive Histiocytosis of the Breast.

Anaplastic lymphoma kinase (ALK)-positive histiocytosis is a rare emerging entity characterized by systemic or localized proliferation of histiocytes harboring ALK rearrangements. Breasts are reportedly affected by ALK-positive histiocytosis. Here, we evaluated 2 localized cases of breast ALK-positive histiocytosis through a comprehensive clinicopathologic, molecular, and genomic analysis to further delineate this entity and better understand its pathogenesis.

Molecular Characteristics of Lymphocyte-predominant Triple-negative Breast Cancer.

Background/aim: Tumor-infiltrating lymphocytes (TILs) are considered a prognostic marker for triple-negative breast cancer (TNBC). Immune checkpoint inhibitor (ICI)-based treatments are more effective for tumors with PD-L1-positive TILs, suggesting crucial roles of TILs in the local tumor immunity. However, factors attracting TILs are still largely unknown.

Identification of a Novel MAN1A1-ROS1 Fusion Gene Through mRNA-based Screening for Tyrosine Kinase Gene Aberrations in a Patient with Leiomyosarcoma.

Background: Soft tissue sarcomas are a heterogeneous group of rare malignant tumors. Advanced soft tissue sarcomas have a poor prognosis, and effective systemic therapies have not been established. Tyrosine kinases are increasingly being used as therapeutic targets for a variety of cancers and soft tissue sarcomas.

is negatively regulated by Kit in gastrointestinal stromal tumors.

Our group has previously demonstrated that pfetin, encoded by the gene, is a strong prognostic biomarker for gastrointestinal stromal tumors (GISTs). However, the underlying mechanisms that control pfetin expression remain unknown. To elucidate the regulatory mechanisms of in GIST, in addition to a possible association between alterations and protein expression, we examined 76 patients with GISTs for mutations by PCR-direct sequence, and compared these results with clinicopathologic data.

Pneumothorax caused by cystic and nodular lung metastases from a malignant uterine perivascular epithelioid cell tumor (PEComa).

Perivascular epithelioid cell tumors (PEComas) are mesenchymal neoplasms with immunoreactivity for both melanocytic and smooth muscle markers. PEComas occur at multiple sites, and malignant PEComas can undergo metastasis, recurrence and aggressive clinical courses. Although the lung is a common metastatic site of PEComas, they usually appear as multiple nodules but rarely become cystic or cavitary.

In Japanese patients with papillary thyroid carcinoma, TERT promoter mutation is associated with poor prognosis, in contrast to BRAF mutation.

The prognostic value of BRAF and TERT promoter mutation in papillary thyroid carcinoma (PTC) is controversial. We examined alterations in BRAF and TERT promoter by PCR-direct sequencing in PTC of 144 Japanese patients. Alternative lengthening of telomeres was examined as another mechanism of telomere maintenance by immunohistochemical staining for ATRX and DAXX.

Expression of adipophilin in gastric epithelial neoplasia is associated with intestinal differentiation and discriminates between adenoma and adenocarcinoma.

Adipophilin, a lipid droplet-associated protein that regulates lipid droplet structure and formation, is expressed in a wide variety of tumors. The aims of this study were to evaluate the frequency and distribution pattern of adipophilin expression in gastric epithelial neoplasia and to correlate these variables with clinicopathological features and the mucin phenotype. We retrospectively examined 159 cases of gastric epithelial neoplasia, which were classified according to the Vienna classification system as 52 noninvasive low-grade adenoma (category 3), 65 noninvasive high-grade neoplasia (category 4), and 42 invasive neoplasia (category 5).

Sarcomatous transformation of EGFR and TP53 mutation-positive metastatic adenocarcinoma of the lungs, masquerading as a primary pleomorphic sarcoma of the proximal femur.

We investigated a case of metastatic adenocarcinoma of the lungs at the left proximal femur, masquerading as a primary pleomorphic sarcoma. A 72-year-old woman presented with pain in her left thigh in conjunction with a mass that had been gradually growing over a few months. She was being treated with gefitinib for lung adenocarcinoma positive for the epidermal growth factor receptor (EGFR) mutation L858R, and had multiple bone metastases.

A case of low-grade fibromyxoid sarcoma with unusual central necrosis in a 77-year-old man confirmed by FUS-CREB3L2 gene fusion.

Introduction: Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft tissue tumor typically affecting young to middle-aged adults. Despite its otherwise benign histologic appearance and indolent nature, it can display fully malignant behavior, and recurrence and metastasis can occur even decades after diagnosis.

Presentation Of Case: Herein, we report a case of LGFMS in the buttock of a 77-year-old man.

Deeply located low-grade fibromyxoid sarcoma with FUS-CREB3L2 gene fusion in a 5-year-old boy with review of literature.

Background: Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft tissue tumor typically affecting young to middle-aged adults. Despite its otherwise benign histologic appearance and indolent nature, it can have fully malignant behavior, and recurrence and metastasis may occur even decades later.

Case History: We report a case of LGFMS in the left lower leg of a 5-year-old Japanese boy.

A case of (123)I-MIBG scintigram-negative functioning pheochromocytoma: immunohistochemical and molecular analysis with review of literature.

A 70-year-old Japanese woman was referred to our hospital due to hyperhidrosis and rapid weight loss of 10 kg in a month. A lump measuring 26 mm in diameter was detected in the left adrenal gland by computed tomography. Biochemical tests showed high levels of serum and urinary norepinephrine and epinephrine.

A case of dedifferentiated solitary fibrous tumor in the pelvis with TP53 mutation.

Solitary fibrous tumors (SFTs), initially observed in the pleura, were later found to develop in almost any extrapleural site. Dedifferentiation within SFTs was characterized only recently. We report a case of dedifferentiated SFT arising within the pelvis of a 70-year-old Japanese woman.

A case of dedifferentiated solitary fibrous tumor of the thoracic cavity.

Solitary fibrous tumors (SFTs), initially observed in the pleura, were later found to develop in almost any extrapleural site. Dedifferentiation within SFTs, a rare phenomenon, was characterized only recently, although it was previously described in soft tissue and bone tumors. We report a case of dedifferentiated SFT arising in the right pleura of a 69-year-old man.

A case of bilateral renal cell carcinoma associated with long-term dialysis showing false-positive immunoreactivity for TFE3 as Xp11 translocation renal cell carcinoma.

Renal carcinomas associated with Xp11.2 translocations/transcription factor 3 (TFE3) gene fusion (Xp11 translocation RCC) are a rare subtype of renal cell carcinoma. A middle-aged Japanese man, who had a medical history of dialysis for more than 12 years, had bilateral renal cancers with a background of acquired cystic disease of the kidney and remarkable deposition of calcium oxalate in the tumorous area.