Outcomes of Infrapopliteal Bypass for Chronic Limb-Threatening Ischemia are Worse in Renal Transplant Patients than in Hemodialysis-Dependent Patients.

BACKGROUND: Comparisons of distal bypass outcomes between hemodialysis-dependent (HD) and renal transplant (RT) patients have been reported, but the influences of immunosuppressive therapy on the outcomes remain unclear because of the limited number of RT patients who underwent distal bypass or cohort heterogenicity. We compared outcomes of distal bypass for chronic limb-threatening ischemia (CLTI) with homogenous ischemic limb pathology. METHODS: Between January 2014 and December 2019, we performed 334 infrapopliteal bypass procedures using vein grafts for 275 consecutive CLTI patients with tissue loss. Among them, there were 130 HD patients (47.3%) (163 limbs) and 11 RT patients (4%) (15 limbs), and 30-day mortality, 5-year primary and secondary patency (PP and SP), limb salvage (LS), amputation-free survival rates, and wound healing (WH) status were compared between the HD and RT patient groups. RESULTS: Nine HD patients died within 30 days after surgery (7%), whereas no deaths were observed among the RT patients. Five-year PP and SP rates in the RT group 39% and 41%, which were significantly worse compared to 64% and 82% in the HD group (P < 0.01). Unsuccessful rate of revision surgery including hemodynamically failed grafts after revision reached over 80% in the RT group, which was technically unfeasible pathology for graft salvage (vs. 3% in the HD group), and WH, and LS rates were significantly worse in the RT group. CONCLUSIONS: In comparison with HD patients, RT patients showed a lower LS rate for CLTI. The lower LS rate was associated with a lower SP rate, which was caused by disease progression of distal arteries in the foot.

Arterial Reconstruction for Patients with Chronic Limb Ischemia Improves Ambulatory Function and Health-related Quality of Life.

BACKGROUND: Arterial reconstruction (AR) for limb ischemia may improve ambulatory function (AF) and health-related quality of life (HR-QoL). However, the efficacy of AR in terms of HR-QoL varies in studies, probably because of cohort differences in disease severity, hemodynamic outcomes, and observation duration. We assessed HR-QoL for patients with various severities of ischemia in a 3-year observational study. METHODS: We conducted a single-center 3-year observational study using Short Form 36 in patients with chronic limb ischemia. Between 2001 and 2009, 515 consecutive patients had AR, and 330 who underwent elective AR consented to the study. Of the 330 patients (claudicants 49%, critical limb ischemia [CLI] 51%), 307 underwent bypass and 23 endovascular therapy. Postal questionnaires were sent after AR, and 8 domains, the physical and mental component summary (PCS and MCS) scores, and the patient-reported AF were compared, and negative predictors were identified. RESULTS: Overall, the MCS was minimally affected, but AF and the PCS were impaired. After AR, these measures were significantly improved, and maximum recovery was attained at 6 months. In subgroup analysis, significant predictors of a negative impact on postoperative PCS included age ≥80, CLI, physical aftereffects of stroke (PAS), and previous major amputation (PMA). Of these, PMA was associated with the lowest PCS score, followed by PAS; for these patients, AR contributed minimally to HR-QoL recovery. PCS scores of claudicants attained a maximum value at 6 months; however, PCS scores of CLI patients were significantly lower than intermittent claudication patients (P < 0.0001), and patients with major tissue loss required 2 years to attain maximum PCS recovery. CONCLUSIONS: This 3-year observational study verified the efficacy of AR in improving AF and HR-QoL. Age ≥80, CLI, PAS, and PMA were definitive predictors, and for patients with the latter 2, AR contributed minimally to improving HR-QoL.

Development of gene therapy with a cyclic adenosine monophosphate response element decoy oligodeoxynucleotide to prevent vascular intimal hyperplasia.

OBJECTIVE: Intimal hyperplasia (IH) is the main cause of therapeutic failure after vascular and endovascular surgery. However, there is currently no targeted therapy for the treatment of IH. We recently reported that the inhibition of cyclic adenosine monophosphate response element (CRE) binding protein (CREB) activation is important in vein graft IH. We focused on a decoy oligodeoxynucleotide (ODN) therapeutic strategy for suppressing IH as a clinical application. The objective of this study was to confirm the therapeutic effect of a CRE decoy ODN in an animal model as a novel therapy for preventing intimal hyperplasia as the first step of the preclinical study of our strategy. METHODS: We designed two phosphorothioate CREs and two scramble decoy ODNs and screened them using a CREB transcription assay to check their ability to bind to a CRE sequence. We chose a CRE decoy ODN with high first-binding ability and transfected it into vascular smooth muscle cells (VSMCs) in vitro. Proliferation and migration were assessed using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assays and modified Boyden chamber assays. We examined CRE activity using a luciferase reporter gene assay. We assessed the expression of messenger RNAs by quantitative real-time polymerase chain reaction. In a wire-injury mouse model (C57BL6, n = 6), CRE decoy ODN was transfected into the injured vessel wall using an ultrasound-sonoporation method in vivo. Mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) and four and a half LIM domains 5 (FHL5) expression of pregrafting vein remnants were assessed by immunohistologic analyses. RESULTS: Compared with scramble decoy ODN, the selected CRE decoy ODN could significantly decrease CRE activity (mean ± standard error of the mean: 0.20 ± 0.03 vs 1.00 ± 0.16, n = 6; P < .05) as shown by a luciferase reporter gene assay, VSMC proliferation (0.73 ± 0.04 vs 0.89 ± 0.02, n = 6; P < .05) and migration (96.4 ± 6.1 vs 311.4 ± 19.1 migrated VSMCs/well, n = 6; P < .05) after 24-hour transfection. The CRE decoy ODN significantly suppressed the formation of IH at injured vessel walls in an animal model, as analyzed by pathologic staining (0.20 ± 0.02 vs 0.56 ± 0.08, area of the intima/area of the artery vs the control after 21 days' transfection, n = 6; P < .05). Furthermore, MAPKAPK3 and FHL5, which are CREB activators, were significantly expressed in pregrafting vein remnants in diabetes mellitus patients. CONCLUSIONS: CREB-CRE signaling is an important mechanism of IH formation, and CRE decoy therapy can help preventing IH. This study is the first part of the preclinical study of our strategy.

Small caliber heparin loaded ultrafine microfiber woven graft achieved high patency rate in a preliminary study of canine carotid artery implantation.

OBJECTIVE: In the past five decades, many small caliber vascular grafts have been developed as bypasses for infrapopliteal or coronary arteries. However, reliable grafts have not been obtained owing to poor patency, mainly caused by early thrombosis or neointimal hyperplasia in the intermediate period after implantation. We developed a novel small caliber heparin-loaded polyethylene terephthalate ultrafine microfiber (HL-PET) graft and evaluated the feasibility to overcome those main causes of graft failure in canine carotid artery implantation. METHODS: The HL-PET graft with a diameter of 3 mm and length of 30 mm was made with combination of three key technologies: (1) weaving with PET ultrafine microfiber with a high biological porosity allowing for cell ingrowth, (2) heparin loading on microfiber surfaces, and (3) an outer coating with a flexible bioabsorbable polymer for prevention of blood leakage and graft kinking. Kink resistance, water permeability, and loaded heparin were assessed. One HL-PET graft each was implanted into a carotid artery of six animals. Graft patency rate and healing were assessed 24 weeks after implantation. RESULTS: Among the six grafts, five were deemed patent (patency rate of >83%), with one occluded 20 weeks after implantation. Histopathology of the patent grafts showed neointima formation with confluent endothelial cell lining (estimated mean endothelial cell coverage area, 89 ± 18%). Intimal hyperplasia at the anastomotic sites and severe chronic inflammatory responses were not observed. Immunohistochemistry with antibodies to endothelial nitric oxide synthase, alpha 2 smooth muscle actin and calponin 1 revealed luminal surface endothelial cell layer with expression of endothelial nitric oxide synthase and vascular smooth muscle cells with contractile phenotype in the subintimal layer. CONCLUSIONS: The HL-PET graft showed no early postoperative thrombosis and was able to demonstrate a high patency rate with no severe biological response observed after 24 weeks. These results strongly suggest the potential of the HL-PET graft to be used for distal bypasses.

A Clampless Aortoprosthetic End to Side Anastomotic Device with Large Diameter Aortic Puncher.

INTRODUCTION: To facilitate safe anastomosis of a vascular prosthesis onto the proximal ascending aorta without side clamping, a clampless anastomotic device with large diameter aortic puncher was developed. REPORT: First, a vascular prosthesis is anastomosed onto the aorta without making a hole, then the aortic wall within the prosthesis is punched out using the device. DISCUSSION: After further refinement of the present device, endovascular surgery with debranching could be performed more safely and quickly.

Increased Incidence of Cancer in Japanese Patients with Critical Limb Ischemia.

Objective: This multicenter observational study was conducted in order to investigate the incidence of cancer in patients with critical limb ischemia. Materials and Methods: We prospectively investigated the incidence of cancer in 68 patients with critical limb ischemia over a two-year period. Patients underwent an intensive examination at enrollment, which included tumor marker levels and chest and abdominal computed tomography, as well as one- and two-year follow-up examinations. We compared the observed incidence of cancer with the expected incidence calculated from national cancer rates by the standardized incidence ratio (SIR). Results: The majority (83.6%) of the patients were men, and 92.5% of the patients had a peripheral arterial disease that was classified as Fontaine stage III or IV. During enrollment, newly diagnosed cancers were detected in seven patients. Four additional cancers were detected during the follow-up period. All of the detected cancers were asymptomatic. We observed an increased risk of cancer (SIR, 4.04; 95% confidence interval, 1.31-9.42) in patients with critical limb ischemia. Conclusion: This study suggests that critical limb ischemia is associated with an increased risk of cancer. Our findings should be taken into serious consideration by future investigators considering the use of therapeutic angiogenesis.

Evaluation of paramalleolar and inframalleolar bypasses in dialysis- and nondialysis-dependent patients with critical limb ischemia.

OBJECTIVE: The aim of this study was to elucidate the efficacy of paramalleolar or inframalleolar bypass (PIMB) in hemodialysis-dependent (HD) patients with critical limb ischemia (CLI) and nonhemodialysis-dependent (NHD) patients in terms of clinical outcomes. METHODS: Between January 2000 and December 2013, there were 333 consecutive arteriosclerosis obliterans patients with CLI who underwent 401 PIMB procedures for limb salvage (LS). Of the 333 patients, 188 (56.5%) were HD patients. Vein grafts were exclusively used, and 172 paramalleolar and 229 inframalleolar bypasses were performed. Five-year primary and secondary cumulative graft patency, LS, and amputation-free survival (AFS) rates were compared between the two groups, and the independent determinants of these outcomes were identified in each group. RESULTS: The 5-year primary and secondary cumulative graft patency rates were 53% and 82% in HD patients and 69% and 92% in NHD patients (primary cumulative graft patency, P < .05; secondary cumulative graft patency, nonsignificant), respectively. The LS rates were 87% and 99% (P < .01) in HD patients and NHD patients, respectively. Overall, 48% and 70% of HD and NHD patients were ambulatory before PIMB (P < .01), and 73% and 85% of HD and NHD patients were ambulatory 12 months after PIMB (including 1-year survivors; nonsignificant), respectively, demonstrating drastic post-PIMB improvement in HD patients. The 5-year AFS rates in the HD and NHD groups were 27% and 69% (P < .01), respectively, demonstrating very poor AFS rates in HD patients. In HD patients, factors negatively associated with AFS were female gender (hazard ratio [HR], 2.102; 95% confidence interval [CI], 1.254-3.524), history of congestive heart failure (HR, 2.075; 95% CI, 1.395-3.085), and preoperative nonambulatory status (HR, 1.974; 95% CI, 1.305-2.986), whereas older age (HR, 2.601; 95% CI, 1.372-4.931) and history of congestive heart failure (HR, 2.928; 95% CI, 1.496-5.731) were identified as independent factors negatively associated with AFS in NHD patients. CONCLUSIONS: The use of PIMB for CLI was associated with excellent LS rates in both HD and NHD patients with low operative mortality and complications. However, the AFS rate observed in HD patients was significantly lower than that observed in NHD patients, indicating the necessity of a specific management program to improve AFS after LS in HD patients.

Venular valves and retrograde perfusion.

Forced retrograde perfusion through the venous system with arterial blood can provide adequate oxygen to peripheral tissues at rest through veno-capillary networks which is the basis for surgical restoration of blood flow by distal vein arterialization (DVA). To be successful such surgery requires disruption of valve leaflets in the veins, which can be accomplished easily in the larger vessels. However, the smallest veins (venules) of less than 100 µm in diameter, also possess valves, are distributed widely throughout all tissues and are too fine for any effective surgical interference. Thus venular valves cannot be disrupted or dissected with presently available technology. Nevertheless, clinical observations suggest that retrograde peripheral blood flow is rapidly established after DVA surgery. There is as yet no rational explanation for this phenomenon. In the present study, using Laplace's law, we attempt to elucidate the mechanical properties of venules and their valves. We speculate that the remarkably thin venular walls (and especially those of the smaller vessels which have the thinnest walls), are capable of considerable, rapid distension when subjected to increased hemostatic pressure. The increase in diameter of venules in response to the increased blood pressure renders their valve leaflets incompetent, so that the valves themselves cannot close the vessel lumen. In addition, the thin bicuspid leaflets may also be forced open retrogradely by the increased blood pressure.

Skin temperature in lower hind limb subjected to distal vein arterialization in rats.

Vascular surgery for distal vein arterialization (DVA) has been adopted clinically as a strategy for saving arteriosclerotic lower limbs from amputation. To gain more detailed information on DVA, the present study investigated the procedure in hind limbs of rats under isoflurane anesthesia. Since successful DVA requires destruction of venous valves, a coronary angioplasty catheter guidewire was used to destroy valves either solely in the femoral vein or in both femoral and popliteal veins. The femoral artery was then anastomosed to the femoral vein with sutures under binocular microsopic control. Changes in the distribution of skin blood flow in the hind limbs were studied with a thermal camera. Skin temperature increased in the thigh and knee after femoral venous valve destruction, but hyperthermia was observed in the distal leg and foot only when the valves in the popliteal vein were also disrupted. These results showed that increased arterial blood flow could be established by DVA surgery in both the proximal and distal regions of the hind limbs.

Clinical results of cystic excision for popliteal artery cystic adventitial disease: long-term benefits of preserving the intact intima.

Surgical treatment for popliteal artery cystic adventitial disease (PACAD) is still controversial. PACAD often occurs in young or middle-aged adults. Therefore, the maintenance of graft patency for very long periods is a concern if a prosthesis is used. Because the intima is intact in PACAD patients with popliteal artery stenosis, a treatment that preserves the healthy intima is ideal. We describe the cases of 3 patients who underwent cystic excision for PACAD with severe stenosis. No recurrence was observed for up to 11 years, and these long-term results revealed that cystic excision could be reconsidered as one of the first-line therapeutic methods.

Biological maintenance of distal vein arterialization.

Eleven weeks after surgery, a fine microvessel network was seen in the feet of patients with arteriosclerosis obliterans treated by distal vein arterialization. A possible mechanism for establishment of blood flow to, and biological maintenance of, the graft in the foot, in relation to oxygen consumption rate during walking was investigated, using Krogh's tissue cylinder model. Our calculations showed that the increase in oxygen consumption rate of the muscle when patients walked would reduce the size of the oxygen front in the tissue cylinder, thus producing small, transient hypoxic regions in skeletal foot muscle. Such muscle hypoxia, although localized, could stimulate synthesis of vascular endothelial growth factor and facilitate angiogenesis in the grafted tissue. The architecture of fine microvessel networks observed in the foot by angiography seems consistent with this supposition and, moreover, suggests that the reinstatement of blood vessel networks in the foot tissues after grafting is supported by "normal" biological mechanisms.

Cyclic adenosine monophosphate response-element binding protein activation by mitogen-activated protein kinase-activated protein kinase 3 and four-and-a-half LIM domains 5 plays a key role for vein graft intimal hyperplasia.

OBJECTIVE: Intimal hyperplasia (IH) is the main cause of vein graft stenosis or failure after bypass surgery. Basic investigations are proceeding in an animal model of mechanically desquamated arteries, and numerous molecules for potential IH treatments have been identified; however, neither insights into the mechanism of IH nor substantially effective treatments for its suppression have been developed. The goals of the present study are to use human vein graft samples to identify therapeutic target genes that control IH and to investigate the therapeutic efficacy of these candidate molecules in animal models. METHODS: Using microarray analysis of human vein graft samples, we identified two previously unrecognized IH-related genes, mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) and four-and-a-half LIM domains 5 (FHL5). RESULTS: Transfer of either candidate gene resulted in significantly elevated vascular smooth muscle cell (VSMC) proliferation and migration. Interestingly, cotransfection of both genes increased VSMC proliferation in an additive manner. These genes activated cyclic adenosine monophosphate response-element (CRE) binding protein (CREB), but their mechanisms of activation were different. MAPKAPK3 phosphorylated CREB, but FHL5 bound directly to CREB. A CREB dominant-negative protein, KCREB, which blocks its ability to bind CRE, repressed VSMC proliferation and migration. In a wire-injury mouse model, gene transfer of KCREB plasmid significantly repressed IH. In this vessel tissue, CRE-activated gene expression was repressed. Furthermore, we confirmed the changes in MAPKAPK3 and FHL5 expression using vein graft samples from eight patients. CONCLUSIONS: We successively identified two previously unrecognized IH activators, MAPKAPK3 and FHL5, using human vein graft samples. Gene transfer of KCREB repressed IH in an animal model. Inhibition of CREB function is a promising gene therapy strategy for IH.

Ruptured aneurysm of coronary artery-to-pulmonary artery fistula.

A 69-year-old lady was discovered unconscious. Computed tomography showed pericardial effusion and a coronary artery aneurysm of 25 mm in diameter in front of the main pulmonary artery. Emergency surgery revealed a coronary-pulmonary artery fistula and coronary aneurysm surrounded by a large hematoma. The inflow and outflow of the fistula were closed, and no cardioplegic leakage was noted. Postoperative angiography showed residual fistulas that were successfully closed by transcatheter embolization.

Prevalence of breast arterial calcification by mammography contributes to breast cancer.

BACKGROUND: Mammographic breast arterial calcifications (BACs) are regarded as aging-related benign changes in breast cancer screening practices. BACs have recently attracted attention, because several researchers proposed using them as a surrogate marker of arteriosclerosis or osteoporosis. No studies have thus far evaluated an association between BACs and breast cancer, however. METHOD: The percentage of BAC positivity was compared between a group of women aged 40 years or older with breast cancer detected in 2004 through 2009, and a group of women of the same age range in whom breast cancer was not detected by screening mammography in 2009. RESULTS: The BAC-positive rate in the group of 243 breast cancer patients was 9.88% (24 of the 243) and was lower than that in the group of women without breast cancer, 14.34% (506 of 3528 women). The analysis by age revealed that the differences in this parameter between the two groups were significant in women aged 60 years or older. Multivariate analysis including demographic characteristics revealed that when adjusted for age and body weight, BAC positivity was a significant risk factor for breast cancer. CONCLUSION: The study results suggest that BAC positivity and, in turn, arteriosclerosis may have an antinomic relationship with breast cancer.

Cerebrovascular disease and intracranial artery stenosis in patients with symptomatic peripheral artery disease.

BACKGROUND: Patients with symptomatic peripheral artery disease (PAD) have an elevated prevalence of internal carotid artery (ICA) stenosis and cerebral infarction, although the correlations between the severity of PAD and cerebral infarction, cerebral white matter lesion (WML), or intracranial or extracranial artery stenosis are unclear. METHODS: We evaluated the prevalence of cardiovascular risk factors, cerebral infarction, and WML on magnetic resonance imaging and intracranial and extracranial carotid artery stenoses on magnetic resonance angiography in patients with symptomatic PAD (n = 136; males/females [M/F] 109/27) and a control group comprised of patients without PAD (n = 92; M/F 57/35). PAD was classified by Fontaine stage (stage II, n = 46; stage III, n = 20; stage IV, n = 70). Cerebral infarctions were classified into symptomatic or asymptomatic groups. WMLs were evaluated according to Fazekas stage. Artery stenosis was classified as normal (no stenosis), mild (stenosis <50%), moderate (stenosis ≥ 50%), severe (tight stenosis), and obstruction on magnetic resonance angiography. RESULTS: Diabetes mellitus (DM), dyslipidemia, coronary artery disease (CAD), and chronic kidney disease (CKD), as well as symptomatic cerebral infarction and WML, were more frequent in patients with Fontaine III/IV PAD than without PAD. The prevalence rates of cerebral infarction and WML in patients with Fontaine stage II PAD were between those of the control and Fontaine III/IV PAD patients. Supraclinoid and cervical ICA stenoses (>50%) were more frequent in patients with Fontaine stage IV PAD than without PAD. CONCLUSIONS: Our results indicate that patients with advanced PAD have an increased prevalence of symptomatic cerebral infarction, WML, and intracranial and cervical ICA stenosis as well as DM, CAD, and CKD.

Surgical treatment of intracystic carcinoma of the breast.

BACKGROUND: Intracystic carcinoma of the breast is a type of breast cancer with favorable prognosis where cancer arises from the cystic wall. However, it is a relatively rare disease, and no general consensus has been reached on its definition, including pathogenesis, extramural invasion, and lymph node metastasis. METHODS: Six patients who underwent surgery at the Department of Surgery at Asahikawa Medical University are presented. In each patient, background factors, diagnosis, surgery, pathological diagnosis, and prognosis were investigated. RESULTS: Fine needle aspiration showed class V disease in three patients and class III disease in the other three, and lumpectomy was performed for class III patients. Three patients underwent breast-conserving surgery While extramural invasion was seen in three patients, lymph node metastasis was absent in all patients. CONCLUSION: When it is difficult to diagnose intracystic carcinoma of the breast by fine needle aspiration, active lumpectomy is necessary. Because extramural invasion and lymph node metastasis have been reported, it is necessary to carefully determine the range of excision and rationally perform lymph node dissection, such as sentinel node biopsy.

Role of treatment for solitary pulmonary nodule in breast cancer patients.

BACKGROUND: Metastatic pulmonary tumors secondary to breast cancer detected either before or after surgery are predominantly multiple and bilateral. However, in cases detected to have a solitary pulmonary nodule (SPN), determining whether the lesion represents a primary cancer, metastasis, or a benign pulmonary lesion can be difficult. MATERIALS AND METHODS: Between January 2000 and December 2009, we performed breast cancer surgery on 1,226 patients, of which 49 cases (3.9%) were detected to have pulmonary lesions before or after the surgery. In 14 of these patients, video-assisted thoracoscopic surgery was performed to remove a SPN. RESULT: Pathological examination of the resected specimens in these 14 cases revealed metastatic pulmonary tumor in 8 cases, primary lung cancer in 3 cases, and benign disease in 3 cases. While lobectomy was performed in one of these patients with metastatic pulmonary tumor, the remaining 7 underwent partial resection of the lung. The primary lung cancer was an adenocarcinoma in all 3 patients, and lobectomy plus mediastinal lymph node dissection was performed in these patients. The tumor grading based on pathological diagnosis was T1N0M0, p-Stage 1A in all 3 patients. The prognosis was good in the breast cancer patients in whom the metastatic lung tumor was a SPN. CONCLUSION: Evaluating the immunohistochemical cytokeratin profile and levels of the TTF-1 and GCDFP-15 of the lesion was useful when distinguishing between pulmonary cancer and metastatic pulmonary tumor. In addition, some patients exhibited changes in the biological properties of the metastatic tumor, and delete tumor resection by video-assisted thoracoscopic surgery can be useful for deciding the drug treatment strategy in some cases.

Mucoepidermoid carcinoma of the lung: a case report.

Mucoepidermoid carcinoma of the lung (MEC) is a tumor of low malignant potential of bronchial gland origin. MEC and adenoid cystic carcinoma are both considered to be salivary gland-type neoplasms. MECs are comparatively rare with an incidence of all lung cancers. We recently encountered a case of this type of lung cancer. A 60-year-old man was found to have an abnormal shadow in the left lower lung field on a regular check-up for lung cancer at his company. Chest radiography and CT revealed a mass shadow measuring 30 mm in diameter in the left lower lung field. Bronchoscopy revealed a protuberant tumor in the S9 bronchus, leading to a diagnosis of low-grade MEC by transbronchial lung biopsy. He underwent left lower lobe resection and mediastinal lymph node dissection using VATS. Tumor cells had a scattering of mucus-producing epithelial components in papillary growth of stratified squamous epithelia with anisokaryosis and minimal pleomorphism, indicating a diagnosis of MEC. Because the postoperative course was good and the tumor was low-grade, no adjuvant treatment was administered. The patient has had no signs of tumor recurrence for 9 months, to date, since resection of the tumor.

Ectopic thymoma presenting as a giant intrathoracic tumor: a case report.

Ectopic thymoma rarely presents as an intrathoracic tumor. We report a case of ectopic thymoma presenting as a giant right intrathoracic tumor that was treated with resection. The patient was a 50-year-old Japanese woman who presented with the chief complaint of chest pain. Detailed examination revealed a solid tumor measuring 15 × 10 × 8 cm in diameter, with a clear border. The Imaging findings suggested a solitary fibrous tumor, and surgery was performed. At surgery, the tumor was found to be adherent to the diaphragm, mediastinal pleura, and lower lobe of the lung, although it could be dissected with relative ease and was removed. Pathological diagnosis indicated a type B1 tumor with no capsular invasion according to the World Health Organization classification, and a diagnosis of Masaoka stage I thymoma was made. No continuity with the normal thymus tissue was seen, and the thymoma was considered to be derived from ectopic thymic tissue in the pleura.