Primary omental smooth muscle tumor in an adult male: a diagnostic dilemma for leiomyoma: a case report.

BACKGROUND: The greater omentum comprises peritoneal, adipose, vascular, and lymphoid tissues. Most omental malignancies are metastatic tumors, and the incidence of primary tumors is rare. We report on a prior omental smooth muscle tumor case in an adult male patient. CASE PRESENTATION: A 54-year-old Japanese male patient with no relevant medical history was diagnosed with an abdominal mass during a routine medical checkup. Subsequent contrast-enhanced computed tomography revealed a mass of approximately 3 cm in size in the greater omentum, and a laparotomy was performed. A 27 × 25 × 20 mm raised lesion was found in the omentum. Microscopically, spindle cells were observed and arranged in whorls and fascicles. Individual tumor cells had short spindle-shaped nuclei with slightly increased chromatin and were characterized by a slightly eosinophilic, spindle-shaped cytoplasm. The mitotic count was less than 1 per 50 high-power fields. The tumor cells showed positive immunoreactivity for α smooth muscle actin, HHF35, and desmin on immunohistochemical examination. The Ki-67 labeling index using the average method was 1.76% (261/14806). No immunoreactivity was observed for any of the other tested markers. We considered leiomyoma owing to a lack of malignant findings. However, primary omental leiomyoma has rarely been reported, and it can be difficult to completely rule out the malignant potential of smooth muscle tumors in soft tissues. Our patient was decisively diagnosed with a primary omental smooth muscle tumor considering leiomyoma. Consequently, the patient did not undergo additional adjuvant therapy and was followed up. The patient was satisfied with treatment and showed neither recurrence nor metastasis at the 13-month postoperative follow-up. DISCUSSION AND CONCLUSION: We encountered a primary smooth muscle tumor of the greater omentum with no histological findings suggestive of malignancy in an adult male patient. However, omental smooth muscle tumors are extremely difficult to define as benign, requiring careful diagnosis. Further case reports with long-term follow-up and case series are required to determine whether a true omental benign smooth muscle tumor (leiomyoma) exists. In addition, proper interpretation of the Ki-67 labeling index should be established. This case study is a foundation for future research.

Continuous alcohol withdrawal delirium and physical illness-associated delirium in a man brought to the emergency department after a disaster: A case report.

BACKGROUND: Risk factors for alcohol withdrawal delirium include heavy drinking, prior alcohol withdrawal delirium or convulsions, nondrug sedative use, and a history of tachycardia, withdrawal, and infections. CASE PRESENTATION: A 76-year-old man with a history of heavy drinking and type 2 diabetes was hospitalized for hypothermia, rhabdomyolysis, and acute renal failure after a typhoon. He developed alcohol withdrawal symptoms 24 h after his last drink, leading to severe withdrawal delirium characterized by restlessness, delusions, and altered consciousness. Treatment included lorazepam, in addition to comprehensive care for his physical condition. His condition fluctuated, especially at night, with his psychiatric symptoms exacerbated by his physical illnesses, suggesting delirium due to the coexistence of severe and multiple physical illnesses. After 44 days, following substantial improvements in both mental and physical health with perospirone, the patient was discharged. CONCLUSION: This case emphasizes the need for multidisciplinary collaboration in the treatment of such patients, especially during disasters, and the importance of long-term monitoring for elderly patients with alcohol dependence syndrome after a disaster.

Evaluation of pancreatic cancer specimens for comprehensive genomic profiling.

Inadequate specimen quality or quantity hinders comprehensive genomic profiling in identifying actionable mutations and guiding treatment strategies. We investigated the optimal conditions for pancreatic cancer specimen selection for comprehensive genomic profiling. We retrospectively analyzed 213 pancreatic cancer cases ordered for comprehensive genomic profiling and compared results from pancreatic biopsy, liver biopsy of pancreatic cancer metastases, pancreatectomy, liquid, and nonliver metastatic organ specimens. We examined preanalytical conditions, including cellularity (tumor cell count/size). The successfully tested cases were those that underwent comprehensive genomic profiling tests without any issues. The successfully tested case ratio was 72.8%. Pancreatic biopsy had the highest successfully tested case ratio (87%), with a high tumor cell percentage, despite the small number of cells (median, 3425). Pancreatic biopsy, liver biopsy of pancreatic cancer metastases, and non-liver metastatic organ had higher successfully tested case ratios than that for pancreatectomy. Liver biopsy of pancreatic cancer metastases and pancreatectomy cases with tumor size (mm2) × tumor ratio (%) > 150 and >3000, respectively, had high successfully tested case ratios. The success of comprehensive genomic profiling is significantly influenced by the tumor cell ratio, and pancreatic biopsy is a potentially suitable specimen for comprehensive genomic profiling.

Clinicopathological analysis of thyroid carcinomas with the RET and NTRK fusion genes: characterization for genetic analysis.

Thyroid carcinomas exhibit various genetic alterations, including the RET and NTRK fusion genes that are targets for molecular therapies. Thus, detecting fusion genes is crucial for devising effective treatment plans. This study characterized the pathological findings associated with these genes to identify the specimens suitable for genetic analysis. Thyroid carcinoma cases positive for the fusion genes were analyzed using the Oncomine Dx Target Test. Clinicopathological data were collected and assessed. Among the 74 patients tested, 8 had RET and 1 had NTRK3 fusion gene. Specifically, of the RET fusion gene cases, 6 exhibited "BRAF-like" atypia and 2 showed "RAS-like" atypia, while the single case with an NTRK3 fusion gene presented "RAS-like" atypia. Apart from one poorly differentiated thyroid carcinoma, most cases involved papillary thyroid carcinomas (PTCs). Primary tumors showed varied structural patterns and exhibited a high proportion of non-papillary structures. Dysmorphic clear cells were frequently observed. BRAF V600E immunoreactivity was negative in all cases. Interestingly, some cases exhibited similarities to diffuse sclerosing variant of PTC characteristics. While calcification in lymph node metastases was mild, primary tumors typically required hydrochloric acid-based decalcification for tissue preparation. This study highlights the benefits of combining morphological and immunohistochemical analyses for gene detection and posits that lymph node metastases are more suitable for genetic analysis owing to their mild calcification. Our results emphasize the importance of accurate sample processing in diagnosing and treating thyroid carcinomas.

SMARCA4-deficient tumors in the adrenal gland and small intestines: A rare case report.

Thoracic SMARCA4-deficient undifferentiated tumors (SMARCA4-UTs) are rare undifferentiated thoracic malignancies with poor prognosis. They predominantly affect young men who are heavy smokers. Recently, the category of SMARCA4-deficiency-related malignancy has been expanded to include extra-thoracic sites, such as the paranasal sinuses, gastrointestinal tract, ovary, and uterus. We report a rare case of SMARCA4-deficient tumors in the adrenal gland and small intestines. SMARCA4-deficient tumors should be included in the differential diagnosis when multiple large masses with heterogeneous contrast effect and strong accumulation are seen in cancers of unknown primary on 18F-fluorodeoxyglucose (FDG) positron emission tomography with computed tomography (PET/CT).

Role of PPARα in inflammatory response of C2C12 myotubes.

Recent studies have shown a role of inflammation in muscle atrophy and sarcopenia. However, no anti-inflammatory pharmacotherapy has been established for the treatment of sarcopenia. Here, we investigate the potential role of PPARα and its ligands on inflammatory response and PGC-1α gene expression in LPS-treated C2C12 myotubes. Knockdown of PPARα, whose expression was upregulated upon differentiation, augmented IL-6 or TNFα gene expression. Conversely, PPARα overexpression or its activation by ligands suppressed 2-h LPS-induced cytokine expression, with pemafibrate attenuating NF-κB or STAT3 phosphorylation. Of note, reduction of PGC-1α gene expression by LPS treatment for 24 hours was partially reversed by fenofibrate. Our data demonstrate a critical inhibitory role of PPARα in inflammatory response of C2C12 myotubes and suggest a future possibility of PPARα ligands as a candidate for anti-inflammatory therapy against sarcopenia.

Review of the Developing Landscape of Prostate Biopsy and Its Roles in Prostate Cancer Diagnosis and Treatment.

Prostate cancer remains a significant global health challenge. Traditionally anchored by the Gleason score/Grade Group (GS/GG), the landscape of prostate cancer diagnosis is undergoing transformative steps, particularly in the domain of biopsy procedures. GS/GG continues to be pivotal in malignancy grading, but recent technological strides have augmented the diagnostic relevance of biopsies. Integral to this progression is the adoption of advanced imaging techniques, especially magnetic resonance imaging, which has refined biopsy accuracy and efficiency. A deep understanding of prostate cancer pathology reveals a cribriform pattern and intraductal carcinoma of the prostate as independent forms of malignancy, suggesting a potentially aggressive disease course. Furthermore, the distinct behaviour of ductal adenocarcinoma and small cell carcinoma of the prostate, compared with acinar adenocarcinoma, necessitates their accurate differentiation during biopsy. The genomic era ushers in a renewed emphasis on tissue samples obtained from prostate biopsies, especially as mutations in genes, such as BRCA1/2, and paves the way for precision medicine. This review encapsulates the evolving dynamics of prostate biopsy, from technological advancements to the profound implications on prostate cancer management and therapy.

Review of the Developing Landscape of Prostate Biopsyand Its Roles in Prostate Cancer Diagnosis andTreatment

Prostate cancer remains a significant global health challenge. Traditionally anchored by the Gleason score/Grade Group (GS/GG), the landscape of prostate cancer diagnosis is undergoing transformative steps, particularly in the domain of biopsy procedures. GS/GG continues to be pivotal in malignancy grading, but recent technological strides have augmented the diagnostic relevance of biopsies. Integral to this progression is the adoption of advanced imaging techniques, especially magnetic resonance imaging, which has refined biopsy accuracy and efficiency. A deep understanding of prostate cancer pathology reveals a cribriform pattern and intraductal carcinoma of the prostate as independent forms of malignancy, suggesting a potentially aggressive disease course. Furthermore, the distinct behaviour of ductal adenocarcinoma and small cell carcinoma of the prostate, compared with acinar adenocarcinoma, necessitates their accurate differentiation during biopsy. The genomic era ushers in a renewed emphasis on tissue samples obtained from prostate biopsies, especially as mutations in genes, such as BRCA1/2, and paves the way for precision medicine. This review encapsulates the evolving dynamics of prostate biopsy, from technological advancements to the profound implications on prostate cancer management and therapy (AU)

Histological findings of thyroid cancer after lenvatinib therapy.

AIMS: Lenvatinib is a multikinase inhibitor used for treating unresectable or metastatic cancers, including thyroid cancer. As total thyroidectomy followed by radioactive iodine therapy is a commonly recommended initial treatment for thyroid cancer, histological findings of the thyroid after lenvatinib therapy remain unclear. Therefore, the aim of this study was to analyse in-vivo changes in patients who underwent thyroidectomy after lenvatinib therapy. METHODS AND RESULTS: We screened 167 patients with thyroid cancer [papillary thyroid cancer (PTC), n = 102; follicular thyroid cancer (FTC), n = 26; anaplastic thyroid cancer (ATC), n = 39] who underwent lenvatinib therapy. Among these patients, six underwent thyroidectomy (lenvatinib-treated group: PTC, n = 3; FTC, n = 1; ATC, n = 2), and the specimens were examined. Five patients with PTC who did not receive lenvatinib therapy were included for comparison (untreated group). Microvessel density (MVD) was evaluated in both groups. The PTC and FTC specimens showed relatively more ischaemic changes than ATC specimens. Coagulative necrosis and ischaemic changes in cancer cells were frequently observed. ATC specimens showed fibrosis and mild cell damage. As hypothyroidism is a common side effect of lenvatinib therapy, non-cancerous thyroid tissues were also examined. Histological findings included mild lymphocytic infiltration, lymphoid follicular formation, histiocytic reaction and follicular epithelial destruction. The MVD in lenvatinib-treated tissues was significantly lower than that in untreated tissues. CONCLUSIONS: Lenvatinib therapy probably induces relatively specific ischaemic changes in thyroid cancer cells. Moreover, inflammatory cell infiltration and decreased MVD occur to varying degrees in non-cancerous thyroid tissue and may be related to hypothyroidism, a side effect of lenvatinib.

Cribriform pattern and intraductal carcinoma of the prostate can have a clinicopathological impact, regardless of their percentage and/or number of cores.

Cribriform pattern and intraductal carcinoma of the prostate (IDC-P) are widely accepted as poor prognostic factors in prostate cancer. However, it remains unclear to what extent the presence of these morphological features in prostate biopsy specimens, as diagnosed by hematoxylin-eosin-stained specimens only, affects the clinicopathological impact. In this study, we summarized the characteristics of the cribriform pattern and IDC-P in 850 prostate biopsy cases. The results showed a statistically significant increase in the incidence of cribriform pattern and IDC-P as grade group (GG) increased (especially in cases ≥ GG4, Chi-square test P < 0.001). The independent risk factors for cribriform pattern and IDC-P in biopsy specimens in the multivariate logistic regression analysis were the former GG, presence of IDC-P, lesion length of the highest GG core, latter GG, presence of the cribriform pattern, number of biopsies obtained, and number of highest GG core. Overall, 125 cases in which radical prostatectomy was conducted after biopsy were selected for further analysis. Multivariate logistic regression analysis using biopsy and surgical specimens confirmed that the presence of the cribriform pattern and IDC-P in biopsy specimens were independent risk factors for lymph node metastasis (odds ratios [95% confidence interval] were 6.54 [1.15-37.05] for the cribriform pattern and 23.71 [1.74-322.42] for IDC-P). The presence of the cribriform pattern and/or IDC-P in a biopsy specimen was a significant factor, even if only partially present, indicating lymph node metastasis. However, further validation is required to predict poor prognostic factors more accurately.

Differential diagnosis of uterine adenosarcoma: identification of JAZF1-BCORL1 rearrangement by comprehensive cancer genomic profiling.

BACKGROUND: Uterine adenosarcoma is a rare malignant tumor that accounts for 8% of all uterine sarcomas, and less than 0.2% of all uterine malignancies. However, it is frequently misdiagnosed in clinical examinations, including pathological diagnosis, and imaging studies owing to its rare and non-specific nature, which is further compounded by the lack of specific diagnostic markers. CASE PRESENTATION: We report a case of uterine adenosarcoma for which a comprehensive genomic profiling (CGP) test provided a chance to reach the proper diagnosis. The patient, a woman in her 60s with a history of uterine leiomyoma was diagnosed with an intra-abdominal mass post presentation with abdominal distention and loss of appetite. She was suspected to have gastrointestinal stromal tumor (GIST); the laparotomically excised mass was found to comprise uniform spindle-shaped cells that grew in bundles with a herringbone architecture, and occasional myxomatous stroma. Immunostaining revealed no specific findings, and the tumor was diagnosed as a spindle cell tumor/suspicious adult fibrosarcoma. The tumor relapsed during postoperative follow-up, and showed size reduction with chemotherapy, prior to regrowth. CGP was performed to identify a possible treatment, which resulted in detection of a JAZF1-BCORL1 rearrangement. Since the rearrangement has been reported in uterine sarcomas, we reevaluated specimens of the preceding uterine leiomyoma, which revealed the presence of adenosarcoma components in the corpus uteri. Furthermore, both the uterine adenosarcoma and intra-abdominal mass were partially positive for CD10 and BCOR staining. CONCLUSION: These results led to the conclusive identification of the abdominal tumor as a metastasis of the uterine adenosarcoma. The JAZF1-BCORL1 rearrangement is predominantly associated with uterine stromal sarcomas; thus far, ours is the second report of the same in an adenosarcoma. Adenosarcomas are rare and difficult to diagnose, especially in atypical cases with scarce glandular epithelial components. Identification of rearrangements involving BCOR or BCORL1, will encourage BCOR staining analysis, thereby potentially resulting in better diagnostic outcomes. Given that platinum-based chemotherapy was proposed as the treatment choice for this patient post diagnosis with adenosarcoma, CGP also indirectly contributed to the designing of the best-suited treatment protocol.

A case of mood disorder with severe side effects of antidepressants in association with resistance to thyroid hormone beta with a THRB mutation.

BACKGROUND: Although resistance to thyroid hormone beta (RTHß) is associated with attention-deficit/hyperactivity disorder, there are few reports of other concomitant mood disorders in individuals with RTHß. CASE PRESENTATION: A 67-year-old woman who had been previously diagnosed with RTHß (Refetoff syndrome) came to our department as a depressed patient. She was hospitalized twice for depression and treated with antidepressants both times. Paroxetine (37.5 mg/day) treatment during the first hospitalization did not cause any side effects, but treatment with mirtazapine (15 mg/day) and venlafaxine (150 mg/day) during the second hospitalization caused clonus and disturbance of consciousness, and these adverse effects resulted in a prolonged period of hospitalization. Finally, the patient's symptoms were controlled with quetiapine (75 mg/day). CONCLUSION: Poor tolerability to antidepressants was observed, which may be related to thyroid hormone intolerance. Low doses of quetiapine may contribute to improvements in depression.

A case of pulmonary tumor thrombotic microangiopathy following lymphedema on the lower extremities.

Pulmonary tumor thrombotic microangiopathy (PTTM) is a rare manifestation of malignancy. The antemortem diagnosis is difficult, since patients present with rapidly progressive symptoms. We recently observed a case of PTTM following lymphedema of the lower extremities. We did not reach a diagnosis, even after performing BAL and TBLB. The patient manifested pulmonary hypertension and died on the 9th day of admission. Autopsy revealed a tumor embolism in the pulmonary arterioles accompanied by fibrocellular epithelial cell proliferation, but the primary organ was not identified. To our knowledge, this is the first reported case of PTTM with lymphedema.

Maturity-onset diabetes of the young type 5, presenting as diabetic ketoacidosis with alkalemia: A report of a case.

A 34-year-old man visited our Department of Gastroenterology and Metabolism, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan, because of dry mouth and weight loss. His plasma glucose level was 32.8 mmol/L and serum levels of ketone bodies were increased, but with metabolic alkalemia. He was also suffering from renal tubular hypomagnesemia and hypokalemia. Abdominal computed tomography showed bilateral renal cysts. These findings were suggestive of maturity-onset diabetes of the young type 5. Genetic testing showed heterozygous hepatocyte nuclear factor 1 beta gene deletion. In the present case, it seemed reasonable to view hepatocyte nuclear factor 1 beta gene deletion as the common cause of maturity-onset diabetes of the young type 5-associated diabetic ketoacidosis and tubular malfunction-induced hypokalemic alkalosis. This case exemplifies the importance of hepatocyte nuclear factor 1 beta gene abnormality as a potential cause of diabetic ketoacidosis with alkalemia.

Takotsubo cardiomyopathy after hypoglycemia in a patient with anorexia nervosa.

BACKGROUND: Takotsubo cardiomyopathy, also known as "apical ballooning syndrome", is generally precipitated by endogenous or exogenous stress. Eating disorders are associated with a variety of physical complications. CASE PRESENTATION: We present a case involving a 37-year-old Japanese female with anorexia nervosa. She was admitted because of emaciation with shortness of breath and tiredness, and her weight was 30.0 kg (BMI 10.5 kg/m2) at this admission. On the afternoon of the first day of hospitalization, a simple measurement caused hypoglycemia (20 mg/dL), and she lost consciousness. On the night of the second day of hospitalization, electrocardiogram showed negative T waves in II, III, aVf, and V1-6. Ultrasound echo showed hypokinesia at the apex of the heart and hypercontraction at the base of the heart. The left ventricular ejection fraction was 20%. Rest and oxygen administration gradually improved her cardiac function; the left ventricular ejection fraction also improved to 50% based on echocardiography. Finally, her weight increased to 43 kg (BMI 15.2 kg/m2) with psychiatric treatment, and she was discharged. CONCLUSIONS: The present case shows the clinical features of Takotsubo cardiomyopathy induced by a hypoglycemic event in addition to underlying anorexia nervosa.

Bleeding risks associated with anticoagulant therapies after percutaneous coronary intervention in Japanese patients with ischemic heart disease complicated by atrial fibrillation: A comparative study.

BACKGROUND: Current guidelines recommend early termination of triple therapy and the use of direct oral anticoagulants (DOAC) for non-valvular atrial fibrillation (NVAF) patients who undergo percutaneous coronary intervention (PCI), due to safety concerns. However, to date, real-world medication usage and safety outcomes (specifically bleeding) in NVAF patients with stent implantation have not been well assessed. METHODS: This was a retrospective, observational, medical database cohort study in Japanese ischemic heart disease (IHD) patients with NVAF who underwent PCI between 2012 and 2017. The primary outcome was clinically relevant bleeding; secondary outcomes included individual bleeding events. A multivariate analysis was conducted to identify risk factors affecting the occurrence of clinically relevant bleeding events. RESULTS: The analysis population comprised 5695 patients [3530 received DOACs and 2165 received vitamin K antagonists (VKAs)]. The incidence of primary outcome events (clinically relevant bleeding/100 patient-years) was 6.05 in the DOAC group and 8.42 in the VKA group, resulting in a nonsignificant 21% lower risk in the DOAC group. The DOAC group also had a nonsignificant 24%, 24%, and 34% lower risk of bleeding requiring transfusion, intracranial bleeding, and lower gastrointestinal bleeding, respectively, compared with the VKA group. A multivariate analysis of the primary outcome showed a significantly higher risk of bleeding among older patients and those with lower body weight and abnormal renal function. CONCLUSIONS: In this retrospective real-world evaluation of IHD patients with NVAF and PCI, DOAC-treated patients had a lower risk of developing clinically relevant bleeding compared with the VKA group.

Clozapine-associated severe eosinophilia following lithium rebound neutropenia: A case report.

BACKGROUND: Clozapine use is complicated by an increased risk of hematological adverse effects such as neutropenia and, rarely, eosinophilia. CASE PRESENTATION: We present the case of a 48-year-old man with treatment-resistant schizophrenia. On day 12 after clozapine initiation, he had a cough with a temperature of 39.8°C. On day 16, his leukocyte count had increased to 9320 cells/mm3 (neutrophils 7550 cells/mm3 and eosinophils 680 cells/mm3 ). We discontinued lithium because of neutrophilia and damage to renal function on day 20. His eosinophil count increased until day 29, reaching 6750 cells/mm3 . We suspected a drug-induced reaction and discontinued clozapine on day 30. His eosinophil count gradually decreased, reaching the normal range by day 40. However, his leukocyte and neutrophil counts also gradually decreased to below than the normal range by day 40. His leukocytes and neutrophil counts had recovered by day 55. CONCLUSION: We concluded that this patient had clozapine-associated severe eosinophilia following lithium rebound neutropenia.

Effect of Asfotase Alfa on Muscle Weakness in a Japanese Adult Patient of Hypophosphatasia with Low ALP Levels.

A 40-year-old Japanese woman presented to our hospital with general fatigue and muscle weakness. She had a history of premature loss of deciduous teeth at 4 years old, her serum alkaline phosphatase (ALP) activity was as low as 91 U/L, and radiologic studies revealed thoracic deformity and sacroiliac calcification. Genetic sequencing revealed a heterozygous c.1559delT mutation in the tissue non-specific alkaline phosphatase gene (ALPL). Based on these findings, she was diagnosed with hypophosphatasia (HPP), and treatment with asfotase alfa, a recombinant human tissue-nonspecific alkaline phosphatase (TNSALP), was initiated. After six months of treatment with asfotase alfa, improvements were observed in the SF-36 score, six-minute walk distance, and grasping power. Although the overdiagnosis needs to be avoided, HPP should be considered in patients with undiagnosed musculoskeletal symptoms and a low serum ALP activity.

A Case of Euthyroid Graves' Ophthalmopathy in a Patient Sero-Negative for TSH Receptor Autoantibody.

We report of a case of Graves' ophthalmopathy presented solely with symptoms of the eyes with normal thyroid function tests and negative immunoreactive TSH receptor autoantibody. 40-year-old male was referred to our hospital due to 2-month history of ocular focusing deficit without any signs or symptoms of hyper- or hypothyroidism. Serum thyroid function tests and 99mTc uptake were both within the normal range. Anti-thyroid autoantibodies were all negative except for the cell-based assay for serum TSH receptor stimulating activity. Since orbital CT scan and MRI gave typical results compatible with Graves' ophthalmopathy, we treated the patients with corticosteroid pulse therapy and orbital radiation therapy, leading to a partial improvement of the symptoms. This case gives insights into the potential pathophysiologic mechanism underlying Graves' ophthalmopathy and casts light upon the difficulties of establishing the diagnosis in a euthyroid case with minimal positive results for anti-thyroid autoantibodies.

An Autopsy Case of Pulmonary Tumor Thrombotic Microangiopathy Due to Rapidly Progressing Colon Cancer in a Patient with Type 2 Diabetes.

We herein describe a case of pulmonary tumor thrombotic microangiopathy (PTTM) with rapidly progressing colon cancer. A 61-year-old man who had been receiving treatment for type 2 diabetes mellitus for 3 years was hospitalized due to critical hypoxemia. Computed tomography, which had not shown any abnormalities 3 months previously, revealed a tumor in the ascending colon, multiple nodules in the liver, and the absence of any lung abnormalities. On day 3 of hospitalization, a sudden onset of severe dyspnea and tachycardia occurred, followed by death. Autopsy revealed microscopic metastatic tumor emboli in multiple pulmonary vessels with fibrin thrombus and intimal proliferation, which led to a diagnosis of PTTM.