Shotaro Maeda

Immunohistochemical localization of endothelial cell markers in solitary fibrous tumor

Solitary fibrous tumor (SFT) is an uncommon tumor first reported in the pleura, but recently described in other tissues. CD34, which is expressed in hematopoietic stem cells, endothelial progenitor cells and vascular endothelial cells, is observed in most SFT and some investigators believe that its expression is a definitive marker of this tumor. In the present study, the expression of vascular endothelial cell markers, such as vascular endothelial growth factor receptor (VEGFR)‐1 (flt‐1), VEGFR‐2 (flk‐1/KDR), Tie‐2 and c‐Met, was examined in SFT to clarify the relationship between SFT and endothelial cells. By immunohistochemical staining of tumor cells from 26 patients, VEGFR‐1 was detected in 24 (92%), VEGFR‐2 in five (19%), Tie‐2 in 14 (54%), and c‐Met, a specific receptor of hepatocyte growth factor (HGF) in 23 patients (88%). Furthermore, VEGFR‐3 (flt‐4) immunoreactivity was detected in eight of 26 patients (31%). In contrast, VEGF, VEGF‐C and HGF, which are ligands for the receptors, were not localized in the SFT cells. These findings indicate that most SFT may closely relate to vascular or lymphatic endothelial cells and the endothelial growth factors may contribute to the growth of SFT in a paracrine manner.

Intracortical osteoblastic osteosarcoma with oncogenic rickets

Abstract Intracortical osteosarcoma is the rarest variant of osteosarcoma, occurring within, and usually confined to, the cortical bone. Oncogenic osteomalacia, or rickets, is an unusual clinicopathologic entity in which vitamin D-resistant osteomalacia, or rickets, occurs in association with some tumors of soft tissue or bone. We present a case of oncogenic rickets associated with intracortical osteosarcoma of the tibia in a 9-year-old boy, whose roentgenographic abnormalities of rickets disappeared and pertinent laboratory data except for serum alkaline phosphatase became normal after surgical resection of the tumor. Histologically, the tumor was an osteosarcoma with a prominent osteoblastic pattern. An unusual microscopic feature was the presence of matrix mineralization showing rounded calcified structures (calcified spherules). Benign osteoblastic tumors, such as osteoid osteoma and osteoblastoma, must be considered in the differential diagnosis because of the relatively low cellular atypia and mitotic activity of this tumor. The infiltrating pattern with destruction or engulfment of normal bone is a major clue to the correct diagnosis of intracortical osteosarcoma. The co-existing radiographic changes of rickets were due to the intracortical osteosarcoma.

Fine needle aspiration cytology of primary epithelioid sarcoma. A report of 2 cases.

BACKGROUND Epithelioid sarcoma is a rare soft part tumor, the cytologic features of which have not been fully elucidated to date. We describe the cytologic features in 2 cases of primary epithelioid sarcoma with samples obtained by fine needle aspiration (FNA). CASES Case 1 was a 50-year-old male who complained of a small mass in his left palm. Case 2 was a 56-year-old female who presented with a mass on the medial aspect of her right forearm. Preoperative FNA smears in both cases showed loose, aggregated and isolated tumor cells that were round to polygonal, with eccentrically located nuclei, against a background of inflammation and necrosis. The tumor cells showed moderate atypia, irregularity in size and many mitoses. In case 1 a presumptive diagnosis of epithelioid sarcoma was made by FNA cytology, while in case 2, FNA cytology revealed a high grade sarcoma with abundant matrix mimicking osteoids, difficult to differentiate from an extraskeletal osteosarcoma. CONCLUSION Epithelioid sarcoma may be difficult to differentiate from an extraskeletal osteosarcoma in cases with abundant hyalinized collagen on FNA cytology.

Primary leiomyoma of the pancreas.

SummaryWe report the first documented case of a primary leiomyoma of the pancreas. A 72-yr-old female patient was admitted to our hospital for the follow-up of a pancreatic tumor detected 2 yr previously at a different hospital. Diagnostic images revealed the presence of a tumor located in the head of the pancreas. The tumor was characterized by a clear margin, hypervascularity, and was a homogenous mass. Moreover, the tumor had not changed in size or characteristics since a previous computed tomography (CT) scan performed 2 yr previously. The tumor was preoperatively diagnosed as a nonfunctional islet-cell tumor or papillary cystic tumor. During the operation, the tumor was found to be encapsulated and showed no signs of direct invasion to neighboring structure. Tumorous lesions of the liver or swellings of the neighboring lymph nodes suggesting metastasis were not found. Instead of a pancreatoduodenectomy, the tumor was enucleated. Microscopically, immunohistochemical studies of a resected specimen indicated a myogenic origin, and neither mitotic activity nor hemorrhagic and necrotic findings were recognized. No signs of recurrence have been seen since its excision. Accordingly, the tumor was diagnosed as a primary leiomyoma of the pancreas.

Cytological interface of diffusely infiltrating astrocytoma and its marginal tissue

Cytological differences between infiltrating lesions of the diffusely infiltrating astrocytoma (DIA) and reactive gliosis at its periphery have not yet been established. We compared histological specimens from cytological crush preparations of 200 brain tumors to characterize the cytology of the DIA and to discriminate it from reactive gliosis. First, the cytological findings of the backgland brain parenchyma were assessed. Second, we looked at the nuclear characteristics of the DIA, comparing them with those of other brain tumors. Third, the cytology of the infiltrating DIA was assessed together with brain parenchymal elements. Finally, we characterized discriminative points of the area of infiltration of the DIA versus those of the reactive gliosis. In addition, we assessed the relations between the cytological findings of the DIA and its MRI images. The cytological findings of this area are important because the surgeon may have to make a rapid diagnosis regarding the existence of the tumor.

Complete Cure of Malignant Lymphoma of the Stomach with a Huge Adrenal Lesion Achieved by Preoperative Chemotherapy and Surgery: Report of a Case

Abstract We report herein the case of a 53-year-old woman with malignant lymphoma of the stomach who was successfully treated by preoperative chemotherapy and surgery. The patient consulted our hospital with the chief complaint of upper abdominal pain. Endoscopy demonstrated a protruding lesion at the antral posterior wall of the stomach, and a post-biopsy pathological diagnosis of diffuse large cell type B-cell lymphoma was established. Moreover, abdominal ultrasonography, computed tomography, and magnetic resonance imaging demonstrated a tumor measuring approximately 10 cm in diameter in the left adrenal gland. A total of three courses of chemotherapy using the CHOP regimen were given preoperatively. The CHOP regimen consisted of 100 mg of prednisolone administered for 8 days together with 1.9 mg of vincristine, 1 000 mg of cyclophosphamide, and 60 mg of epirubicin administered intravenously on the first day. This resulted in tumor shrinkage, and a distal gastrectomy, lymph node dissection, and left adrenalectomy were subsequently performed. Since the pathological findings of the resected tissue specimen demonstrated complete elimination of the malignant lymphoma, this combination of procedures was defined as having resulted in a complete response. The postoperative course of this patient was uneventful. She is still alive without any sign of tumor recurrence 6 years after her operation, and is being followed up at the outpatient clinic.

Malignant glomus tumor arising among multiple glomus tumors

A 64-year-old man visited our hospital complaining of pain of the right lower leg. He noticed plural painful soft tissue tumors in the right lower leg at about age 22, which were extirpated by a nearby physician. Since about age 30, multiple painful soft tumors reappeared over the area from the right lower leg to the foot and were extirpated during several operations up to age 36. Although the patient was aware of the presence of a few more tumors, they were left alone. At about age 64, multiple small painful tumors reappeared over the area from the right knee to the foot. When one of the tumors in the medial part of the center of the right lower leg enlarged to about 3 cm and became painful, the patient visited our department. The pathological diagnosis of tumors extirpated previously was unclear. His clinical history and family history were uneventful. Physical examination revealed multiple tumors of several millimeters over an area from the distal part of the right thigh to the foot, with a tumor of 3 cm diameter in the medial part of the center of the right lower leg. The tumors were elastic and soft with clear borders and were painful and tender. The latter tumor had less mobility than the others. Tinel’s sign and neurological fi ndings were negative. The right knee had 20° limitation in extension, and the ankle joint had 20° limitation in dorsifl exion. Hematological, biochemical, and general urological tests showed no abnormality. A scout roentgenogram was normal. Enhanced computed tomography (CT) showed a tumor with a clear boundary and contrast effects under the fascia in the medial part of the right lower leg (Fig. 1). MRI revealed the lesion to have a signal equal to that of muscle on the T1-enhanced image and high signal intensities on the T2-enhanced image. The 2.8 × 1.3 cm tumor with gadolinium enhancement is shown in Fig. 2. MRI also revealed several small

CD30-positive diffuse large B-cell lymphoma with microvillous features: so-called microvillous lymphoma

A case of CD30-positive microvillous lymphoma (MVL) in an 87-year-old man who was encountered generalised lymphadenopathy is presented. Histopathologically, the tumour showed a morphological mimic of anaplastic large cell lymphoma (ALCL) with sinusoidal growth pattern. Immunohistochemically (IHC), the tumour cells were CD30+, CD20+, CD45+, BCL-2+, BCL-6+, MUM1+, Ki-67+, CD45RO−, CD3−, CD10−, CD15−, CD56−, EMA−, TIA-1− and ALK−. Flow cytometry confirmed the IHC. In situ hybridisation for Epstein–Barr virus RNA was negative. Electron microscopically, the tumour cells were similar to large transformed lymphocytes and had circumferentially profuse microvillous projections resembling those of epithelial mesothelioma cells. In conclusion, CD30-positive MVLs are indistinguishable from ALCLs that have ultrastructural microvillous projections by morphology alone. However, the lack of EMA, TIA-1 and ALK expression in this MVL case facilitated a definite distinction from ALCLs. The results of a panel of three markers (CD10−, Bcl-6+ and MUM1+) suggested that the present case of CD30-positive MVLs has an activated non-germinal centre B-cell origin.

A case of recurrent epithelioid sarcoma suggested by aspiration cytology.

Epithelioid sarcomaは比較的まれな軟部腫瘍で若年成人の前腕, 手掌, 指に好発する.この腫瘍は良性, 悪性の鑑別がしばしば問題となるので, 細胞診に携わる者にとって重要である。今回われわれは穿刺吸引細胞診で再発を推定診断しえたEpithelioid sarcomaの1症例を経験したので報告する。患者は44歳女性で, 右手掌部の腫瘤を主訴として当院に入院した.細胞所見では, 大型類円形ないし多稜形の細胞が主として粗な結合性の小集塊としてみられ, 線維芽細胞様紡錘形細胞も散見された.組織所見では, 腫瘍細胞は結節性に増殖し, 中心壊死傾向がみられた。免疫細胞化学的にkeratin, EMA, TPA, CEA, vimentin, actinが陽性, 電顕的にintermediate filament, desmosome様接着装置が証明された.