Hiroaki Takeo

Aberrant cytokeratin 7 expression of centrilobular hepatocytes: a clinicopathological study

Matsukuma S, Takeo H, Kono T, Nagata Y & Sato K 
(2012) Histopathology 61, 857–862

Primary pulmonary myxoid sarcoma with EWSR1‐CREB1 fusion, resembling extraskeletal myxoid chondrosarcoma: Case report with a review of Literature

Reported herein is an extremely rare case of primary pulmonary myxoid sarcoma (PPMS). A 31‐year‐old man presented with a 2.7 cm‐sized pulmonary tumor surrounded by capsule‐like fibrosis. The patient has been free of disease for 5.8 years after surgery. This tumor focally showed endobronchial features, and consisted of reticular cords of oval, short spindle, or polygonal cells with swollen vesicular nuclei accompanied by an abundant myxoid stroma, closely resembling extraskeletal myxoid chondrosarcoma. Tumor cells were diffusely positive for vimentin and focally positive for epithelial membrane antigen, but were negative for cytokeratin, TTF‐1, Napsin A, S‐100 protein, CD34, desmin, smooth‐muscle actin, CD10, p63, calponin, h‐caldesmon, c‐kit, HMB‐45, synaptophysin, or glial fibrillary acid protein. Our reverse transcription‐polymerase chain reaction using the formalin‐fixed, paraffin‐embedded tumor tissues detected EWSR1‐CREB1 fusion transcript, but could not demonstrate EWSR1‐ATF1 fusion or EWSR1/TAF15/TFG‐NR4A3 fusion. These findings indicate that the current tumor is an additional case of PPMS with EESR1‐CREB1 fusion, recently reported by Thway et al. Some cases of PPMS can behave in an indolent manner.

Endoscopically resected colorectal leiomyomas often containing eosinophilic globules

Sir: Mesenchymal neoplasms arising in the gastrointestinal tract are called stromal tumours, which are divided into four categories: tumours with smooth muscle differentiation, tumours with neural differentiation, both or neither. Most recently, the term ‘gastrointestinal stromal tumour (GIST)’ has been restricted to those stromal tumours showing ‘Cajal cell differentiation’. On the other hand, recent advances in endoscopic techniques has allowed the resection of small mesenchymal tumours. We examined 30 cases of endoscopically resected ‘stromal’ nodules of the colorectum, which were retrieved from the files of the Department of Pathology, Japan Self Defense Forces Central Hospital, Tokyo. All patients were asymptomatic men, ranging in age from 43 to 66 years (mean 52.6 years), that underwent colonoscopic examination because of positive faecal occult blood on a routine health check. Thirty endoscopically resected colorectal stromal nodules ranged from 2 to 10 mm in maximum diameter (mean 4.4 mm). Histologically, all nodules originated from the muscularis mucosae and were composed of spindle cells with oval to moderately elongated, blunt-ended nuclei and eosinophilic cytoplasm, resembling well-differentiated smooth muscle cells. Eighteen nodules (18 ⁄ 30, 60.0%) contained multiple eosinophilic globules (EGs)(Figure 1). Immunohistochemically, all the nodules were positive for a-smooth-muscle actin (SMA), muscle-specific actin (HHF-35; Dako, Glostrup, Denmark), and desmin (Histofine kit; Nichirei, Tokyo, Japan). None of the nodules showed immunoreactivity for CD34 (Immunotech, Marseilles, France), CD117 (Dako) or S100 protein (Histofine kit). The EGs were peripherally or diffusely immunoreactive for SMA, HHF-35, and desmin, but were negative for S100, CD34, CD117 and type IV collagen (Dako). In two nodules containing EGs, tissue retrieved from paraffinembedded blocks were refixed in 2.5% buffered glutaraldehyde and examined ultrastructurally. Dense filamentous aggregations, identical to the EGs, were found multifocally in the cytoplasm of the neoplastic cells. These filamentous aggregations were composed of intermediate filaments and microfilaments with focal dense bodies (Figure 2). Based on the immunohistochemical evidence, the aggregated intermediate filaments were considered to be desmin and the microfilaments were considered to be actin. Distinctive features indicating skeinoid fibres were not found. As a control series, we examined colorectal biopsy specimens from 50 ageand sex-matched male subjects ranging in age from 41 to 69 years (mean 52.8 years), with various diseases except smooth muscle tumours, retrieved from the files of the Department of Pathology, Japan Self Defense Forces Central Hospital (from 1995 to 2002). EGs were not found in the non-neoplastic muscularis mucosae of these subjects. The stromal nodules in this series were true leiomyomas originating from the muscularis mucosae and should not be included in the category of GIST.

Gastric tube cancer: Immunohistochemical study of 10 lesions in six patients

Background and Aim:  Gastric tube cancer (GTC), defined as carcinoma arising in the reconstructed gastric tube after esophagectomy, has been increasingly reported, but its pathogenesis remains unclear. Therefore, the aim of this study was to examine clinically and pathologically 10 GTCs in six patients.

Numerous osteoclast-like giant cells in metastases from lung adenocarcinoma, but absent from primary tumor.

We report a rare case of lung adenocarcinoma in a 54‐year‐old man, in whom osteoclast‐like giant cells (OCGCs) were found only in metastases. Autopsy revealed that metastases involving the tongue, gallbladder, stomach, intestines, right adrenal gland, and bones contained numerous OCGCs. Some metastases to the lungs and liver also contained OCGCs, but the primary tumor and metastases to the right atrium, spleen, left adrenal gland, and lymph nodes did not. Primary lung carcinoma cells were positive for cytokeratin 7 (CK7), epithelial membrane antigen (EMA), thyroid transcription factor 1 (TTF‐1), and Napsin A, but were negative for vimentin and CD68. Frequently poorly cohesive metastatic carcinoma cells admixtured with OCGCs showed weak CK7/EMA positivity, no TTF‐1/Napsin A staining, and newly expressed vimentin. OCGCs were positive only for CD68 and vimentin, implying reactive cells. OCGCs can develop only in metastatic lesions, possibly associated with their anaplastic changes or epithelial mesenchymal transition.

Fat cells and membranous fat necrosis of aortic valves: A clinicopathological study

We examined 152 aortic valves (AVs), which included 82 postmortem non‐dysfunctional AVs (nd‐AVs) and 70 surgically removed dysfunctional AVs showing aortic stenosis (AS), aortic regurgitation (AR), or combined AS and AR (AS‐R). Fat cells, membranous fat necrosis (MFN), and fat‐MFN‐related lesions composed of fat cells and/or MFN were found in 127 (83.6%), 110 (72.4%), and 140 (92.1%) of 152 AVs, respectively, and all were associated with older age (P = 0.010, P = 0.022, and P = 0.003, respectively). MFN was associated with fibrous thickening and calcification (both, P = 0.001). Nd‐AV fat cells and fat‐MFN‐related lesions were not correlated with body mass index. Compared with age‐ and sex‐matched control cases, MFN in AS and AS‐R cases was more frequent (P = 0.030 and P = 0.045, respectively), but MFN in AR cases showed no significant differences. Fat‐MFN‐related lesions, possibly representing true preceding fat cells, showed no differences in AVs with and without dysfunction or in dysfunctional types. These data suggest that AV fat cells are age‐related, obesity‐independent, and AV dysfunction‐unrelated common phenomenon. MFN is also age‐dependent and could be caused by AS and AS‐R, which is probably concerned with AV thickening and calcification.

Fatty lesions in intra-articular loose bodies: a histopathological study of non-primary synovial chondromatosis cases

Intra-articular loose bodies (ILBs) are not uncommon conditions in patients with various joint diseases. Their morphological alterations have been investigated in detail, but little attention has been paid to their fatty lesions. In this study, we examined fatty bone marrow, fat cells without bone marrow structures (extramedullary fat cells), and their necrotic changes in 55 ILBs surgically removed from 42 patients, excluding primary synovial chondromatosis cases. The presence of viable re-vascularized vessels with or without enchondral ossification could discriminate 19 re-attached ILBs from 36 true free ILBs. Fatty bone marrow was found in 25 ILBs, and its necrosis was recognized in 11 (44.0%) of them. Extramedullary fat cells, characterized by single or clustered fat cells focally or multifocally distributed in fibrous or cartilaginous stroma, were identified in seven true free ILBs (7of 55, 12.7%), and all of them were focally necrotic. Unique lipomembranous changes were detected in 7 (12.7%) of 55 ILBs; they were found in 4 (36.4%) of 11 ILBs of necrotic bone marrow and were associated with 3 (42.9%) of 7 necrotic extramedullary fatty lesions. These changes were highlighted by periodic-acid Schiff and Massons trichrome stain more clearly. We concluded that extramedullary fat cells represent lipometaplasia in ILBs with no blood supply. We considered that lipomembranous changes in ILBs can be a useful hallmark for necrotic bone marrow or necrosis of extramedullary lipometaplastic lesions.

Lipomatous angiomyofibroblastoma of the vulva: A case report and review of the literature

Lipomatous angiomyofibroblastoma is extremely rare, with only 16 cases reported to date. We herein describe an additional case arising in the left vulvar region of a 49-year-old woman. The resected 5.3-cm yellowish tumor predominantly consisted of fat cells (85% of the tumor), together with medium- and small-sized vessels, multifocal fibrotic areas and pseudoangiomatous spaces. Spindle, rounded, and/or epithelioid tumor cells proliferated in a nest and/or cord-like pattern, or singly within perivascular fibrous tissues and between fat cells. The tumor cells were positive for vimentin, estrogen receptor, progesterone receptor, B-cell lymphoma 2, and CD10, but were negative for desmin, cytokeratin, epithelial membrane antigen, S-100 protein, human melanoma black 45, C-kit and p40. Ultrastructural examination revealed that these tumor cells exhibited fibroblastic characteristics. Lipomatous angiomyofibroblastoma should be discriminated from other lipomatous tumors, including spindle cell lipoma, angiomyolipoma and cellular angiofibroma containing numerous fat cells.

Intra-adrenal bile ductules associated with adreno-hepatic fusion: a possible origin for adrenal epithelial cysts

To elucidate the relationship between the rare phenomenon of adrenal cysts and adreno‐hepatic fusion (AHF)‐related intra‐adrenal bile ductules.

Invasive form of ciliated muconodular papillary tumor of the lung: A case report and review of the literature: Invasive CPMT

We report a case of a 67‐year‐old woman with an invasive ciliated muconodular papillary tumor (CMPT) that developed in her right middle lobe. The current tumor was incidentally detected during a follow‐up imaging examination for a large cell carcinoma that was resected 10 years previously. Partial removal of the middle lobe showed a 2 cm‐sized, solid and myxoid tumor located in the peripheral region. Histologically, this tumor primarily consisted of ciliated columnar cells, mucous cells, and basal cells, all of which had relatively swollen nuclei and were proliferating in a lepidic or papillary/micropapillary manner. These features were consistent with those of previously reported CMPT. In addition, atypical spindle tumor cells with more swollen nuclei, which were partly continuous to less atypical basal tumor cells, were focally found and invaded fibrous stroma in a reticular fashion. Immunohistochemically, both basal cells and atypical spindle tumor cells were positive for pancytokeratin, cytokeratin 5/6, and p40. Increased p53 positivity was found in these invading spindle cells compared with basal tumor cells. Neither BRAF V600E nor V600K mutation was detected. We concluded that this tumor was an extremely rare invasive case of CMPT, possibly representing malignant transformation of basal tumor cell components of CMPT.