FDG PET/CT and MRI Findings of Extraskeletal Myxoid Chondrosarcoma Showing a Nonmyxoid Cellular Variant.

ABSTRACT: We present a new, extremely rare nonmyxoid cellular variant of extraskeletal myxoid chondrosarcoma. Although diagnosis is radiologically and pathologically challenging, FDG PET/CT and MRI accurately showed the malignancy and high tumor density. A 52-year-old woman complained of a left dorsal mass, which presented inhomogeneous intermediate signals on T2-weighted images, with diffusion restriction, strong enhancement, and increased accumulation of FDG (SUV max , 5.2). Although biopsy was inconclusive, a highly malignant tumor was suspected radiologically. The resected specimen was histologically diagnosed as extraskeletal myxoid chondrosarcoma by detection of EWSR1::NR4A3 fusion using fluorescence in situ hybridization.

A case of rectal cancer complicated with segmental arterial mediolysis (SAM) safely treated with curative resection - A case report.

INTRODUCTION: Recent advances in diagnostic imaging techniques have led to an increasing number of case reports of segmental arterial mediolysis (SAM). However, reports of abnormalities associated with SAM of abdominal organs, including the bowel, are limited. SAM, a rare vascular disease that causes spontaneous intra-abdominal bleeding, including shock and intestinal ischemia, has been reported to be associated with high mortality, but it has not been reported to coexist with rectal cancer. CASE PRESENTATION: A 74 year-old male was referred to our hospital with a rectal cancer and he was admitted for further examination. Computed tomography angiography (CTA) revealed dissection and aneurysm in the celiac artery, superior mesenteric artery (SMA), and the inferior mesenteric artery were dilated, leading to a diagnosis of SAM. CLINICAL DISCUSSION: Surgery for rectal cancer requires cutting the inferior mesenteric artery. The risk of bleeding during surgery increases when SAM is associated with the inferior mesenteric artery. The radical surgery for rectal cancer was executed without complications, including significant bleeding. This was achieved through careful management of SAM, meticulous control of blood pressure throughout the surgical procedure, and the delicate treatment of the SMA. A pathological diagnosis of the resected inferior mesenteric artery at the time of radical surgery was performed, and a definitive diagnosis of SAM was made. CONCLUSION: We present a first known case in which high anterior resection was successfully performed for rectal cancer complicated by SAM. The relationship between cancer and SAM is unclear and further case accumulation is needed.

Cytopathology of Chondromyxoid Fibroma: Report of 2 Cases with Immunocytochemical Expression of GRM1.

INTRODUCTION: Chondromyxoid fibroma (CMF) is a rare, benign bone tumor that occurs predominantly in the second and third decades of life, more frequently in males. Overexpression of GRM1 as a consequence of tumor-specific gene rearrangement of GRM1 has recently been reported as a useful immunohistochemical marker for histopathological diagnosis of CMF. However, the usefulness of GRM1 staining of cytology specimens has not yet been evaluated. In this report, the cytological findings and GRM1 immunocytochemistry of two cases of CMF are described. CASE PRESENTATIONS: Case 1 was a 15-year-old girl with a rib tumor. Imaging findings suggested a benign neurogenic tumor such as schwannoma. The tumor had increased in size over a 2-year period and was resected. Case 2 was a 14-year-old boy with a metatarsal tumor involving his left first toe. Imaging findings were suspicious of a benign neoplastic lesion. Biopsy findings suggested a benign tumor, and the patient underwent tumor resection. Cytologically, in both cases the tumor cells were predominantly spindle-shaped or stellate, with a myxoid to chondromyxoid background matrix and multinucleated giant cells, and these matrices were metachromatic with Giemsa staining. Cellular atypia was more accentuated in case 2 than in case 1. Immunocytochemical staining for GRM1 was positive in both cases. CONCLUSION: Due to the overlap in cytological findings, it is often difficult to differentiate CMF from chondroblastoma and chondrosarcoma grade 2. Immunocytochemical staining for GRM1 may support the diagnosis of CMF, and the reuse of Papanicolaou-stained specimens is applicable. The present cases further demonstrated the difficulty of differentiating CMF from other mimicking tumors such as chondroblastoma and chondrosarcoma grade 2. In such instances, immunocytochemistry for GRM1 is applicable to the diagnostic process, the value of which is strengthened by reusing Papanicolaou-stained specimens.

Solitary Fibrous Tumor in the Retroperitoneal Space Arising from the Diaphragm.

BACKGROUND/AIM: We present a case of solitary fibrous tumor, arising from the diaphragm in the retroperitoneal space, that was resected with robotic assistance. CASE REPORT: An 85-year-old female patient was referred to our hospital for evaluation of a suspected right renal tumor. Abdominal contrast-enhanced computed tomography revealed a tumor (maximum diameter, 36 mm) protruding from the superior pole of the right kidney. The patient was scheduled for robot-assisted, retroperitoneoscopic, partial nephrectomy based on a preoperative diagnosis of renal cell carcinoma. Intraoperative findings revealed that the tumor originated from the diaphragm and had no continuity with the renal parenchyma. Pathological examination revealed a solitary fibrous tumor. CONCLUSION: Solitary fibrous tumors are rare soft-tissue neoplasms with a distinct molecular feature of the fusion of nerve growth factor-inducible A gene-binding protein 2 with signal transducer and activator of transcription 6 gene (NAB2::STAT6). We believe that this is the first reported case of a solitary fibrous tumor arising from the diaphragm in the retroperitoneal space.

High-grade endometrial stromal sarcoma with YWHAE-NUTM2B fusion gene abnormality identified after 10 years of recurrent pulmonary metastases: A case report.

•Endometrial stromal sarcoma is the second most common type of uterine sarcoma.•Endometrial stromal sarcoma has undergone modifications since its proposal.•This case highlights the importance of accurately diagnosing endometrial stromal sarcoma.•Asymptomatic uterine fibroids may not be treated with therapeutic intervention or prompt regular check-ups.

Periosteal Myxoid Leiomyosarcoma Histologically Mimicking Extraskeletal Myxoid Chondrosarcoma: Report of a Case with Histopathological and Cytopathological Comparison with Extraskeletal Myxoid Chondrosarcoma.

Myxoid leiomyosarcoma (MLS) is a rare variant of leiomyosarcoma, with most cases occurring in the uterus. A case of MLS arising in the periosteal region of the tibia, mimicking extraskeletal myxoid chondrosarcoma (EMC), is described. The evaluation included histological and cytological comparison with EMC. The patient was a 77-year-old man with a palpable mass at the anterior aspect of the right lower leg. After diagnosis by cytopathology and biopsy examination, a wide resection was performed. The resulting cytological smears were composed primarily of spindle-shaped tumor cells in a myxoid and hemorrhagic background. Histologically, the tumor showed abundant myxoid matrix and tumor cells proliferating in a cord-like to reticular pattern, exhibiting a lace-like arrangement that mimicked EMC. Although immunohistochemical findings suggested leiomyosarcoma, a diagnosis of EMC eventually was excluded by the lack of a split signal when assessed for a rearrangement of NR4A3 by chromogenic in situ hybridization. Despite histological similarity to EMC, characteristic cytological findings of EMC such as epithelioid structures with a cord-like pattern and chondroblast-like lacunar structures were not observed in the smears of this patient's MLS. We propose that cytopathological examination of bone and soft tissue lesions is useful as a diagnostic tool in similar cases. A total diagnostic workup, including clinical, radiographic, cytopathological, histopathological, and molecular findings, is needed to ensure an accurate final diagnosis and to reduce diagnostic error.

Cytological features of BCOR-CCNB3 sarcoma: Comparison with Ewing sarcoma and synovial sarcoma.

INTRODUCTION: BCOR-CCNB3 sarcoma (BCS) is one of the histological types classified as an undifferentiated small round cell sarcoma of bone and soft tissue. This sarcoma frequently develops in males under 20 years of age. Histologically, a delicate capillary network has been reported as a conspicuous finding. In this study, the cytological findings of BCS were observed in two cases of primary lesions and one case of a lung metastatic lesion. The cytological findings of BCS were compared with its histological mimics, and the characteristic findings of BCS were examined. METHODS: Three cases of BCS were studied, and a cytological comparison was performed with 8 cases of Ewing sarcoma (ES) and 10 cases of synovial sarcoma (SS; monophasic type: 7 cases, biphasic type: 2 cases, poorly differentiated: 1 case). RESULTS: In all BCS cases, small clusters with thin and delicate vascular cores and tiny vascular fragments were conspicuous. In ES and SS cases, although small clusters with vascular cores were observed, the vascular cores were thicker than in BCS, and no tiny vascular fragments appeared in most cases. Cytomorphological differences of tumour cells were also observed among BCS, ES, and SS. Predominantly rounded nuclei with fine chromatin and inconspicuous nucleoli can be cytological clues for BCS. CONCLUSIONS: BCS shows characteristic cytological findings that make the diagnosis of BCS more likely than that of ES and SS. Cytological evaluation is a useful tool for appropriate differential diagnosis that leads to a more accurate final diagnosis and rapid treatment.

Systematic Review of Spinal Lymphomatoid Granulomatosis Cases.

Lymphomatoid granulomatosis (LYG) is a rare Epstein-Barr virus-associated systemic angiocentric and angiodestructive lymphoproliferative disorder. It commonly involves the lungs and can also affect the skin, liver, kidney, and central nervous system. It can rarely occur in the spine, however, the details are unclear. We performed a systematic review of published cases (including our 1 case) of spinal LYG. We performed a systematic search of studies in English on spinal LYG, focusing on its clinical features, imaging, and treatments, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines on the PubMed database. We identified 14 patients from the literature. We also found 1 case of isolated cervical LYG (grade 3) who was treated with steroid and radiation therapy for the spinal lesion after pathologic diagnosis. We performed a pooled analysis of these 15 cases. The mean age was 43.4 years, and 13 of the 15 patients were male. Brain lesions were present in 11 of 12 intramedullary spinal lesions, and only 1 was an isolated spinal LYG case. Regarding the diagnostic methods, 1 case was not described. Of the 14 cases described, 12 patients underwent biopsies (7 brain, 4 lung, and 1 spinal cord lesion) and 2 underwent surgical removal for an extramedullary lesion. In the overall prognosis from a mean follow-up period of 21.6 months, 4 patients died despite several treatments. Spinal LYG, particularly isolated spinal LYG, is rare. Thus further accumulation of cases may be necessary to better understand its characteristics.

Concurrent epithelioid hemangioma and diffuse cavernous hemangioma in the rectum clinically mimicking a malignant tumor: a case report.

Epithelioid hemangioma is a rare benign vascular tumor that consists of capillary-sized vessels lined by epithelioid endothelial cells. Diffuse cavernous hemangioma is a congenital benign vascular neoplasm consisting of increased dilated vessels. We report a case of epithelioid hemangioma and diffuse cavernous hemangioma that co-occurred in the rectum. To our knowledge, this is the first report in which two rare vascular lesions coexisted. Because both epithelioid hemangioma and diffuse cavernous hemangioma are often clinically confounded by malignant tumors, differentiating these benign lesions from other possible malignant tumors is significant.

Is Kimura's disease associated with juvenile temporal arteritis? A case report and literature review of all juvenile temporal arteritis cases.

Both juvenile temporal arteritis (JTA) and Kimura's disease are eosinophilic inflammatory conditions but exhibit different clinical manifestations. Here, we describe a case involving a 40-year-old man who developed JTA secondary to Kimura's disease. Approximately 3 years before admission, masses appeared on both posterior auricles. A biopsy of the right posterior auricle mass led to a diagnosis of Kimura's disease. Approximately 4 months before admission, both masses increased in size, and almost simultaneously, the left temporal artery became distended. Histopathology of a biopsy of the left temporal artery revealed inflammatory findings with marked eosinophil infiltration and significant intimal hyperplasia with stenosis of the vascular lumen, indicating JTA. An analysis of the 48 reported cases of JTA, identified in a literature review, and the present case, revealed that Kimura's disease was detected in 6 cases, all of which involved Asians. In conclusion, this case and the literature review suggest that JTA can be accompanied by another eosinophilic inflammation-based disorder, Kimura's disease, particularly in Asians. This newly highlighted relationship between JTA and Kimura's disease could lead to a better understanding of JTA, which is an extremely rare disease.

A young woman who developed ascending colon cancer 2 years after the onset of ulcerative colitis.

Guidelines recommend surveillance colonoscopy for patients with an ulcerative colitis (UC) duration of 8-10 years. We experienced a patient who had not undergone UC surveillance. A 35-year-old Japanese woman developed diarrhea and abdominal pain in January 2018 and was diagnosed with UC. She underwent medical therapy, and 18 months after onset of UC colonoscopy indicated that her UC activity was remission and showed no cancer lesions. Twenty-four months after onset, colonoscopy revealed a tumor in the ascending colon, and the biopsy revealed tubular adenocarcinoma. She had no family history of colorectal cancer. There were no findings of distant metastases or primary sclerosing cholangitis. Laparoscopy-assisted anus-preserving total proctocolectomy, the creation of a J-type ileal pouch, ileal pouch anal anastomosis, and the creation of an ileostomy were performed. The pathological report was type 3, 30 × 27-mm, adenocarcinoma (por2 > tub2), pT4a, Ly1a, V1a, budding grade 3, pN0, M0, Stage IIb. Some colitic cancers such as our patient's may not conform to the existing guidelines. When a colonoscopy is being performed for a UC patient, even if its timing is less < 8 years since the UC onset, suspicious lesions should be biopsied considering the possibility of cancer.

High FDG Uptake in Pleomorphic Hyalinizing Angiectatic Tumor.

PHAT (pleomorphic hyalinizing angiectatic tumor) is a rare, locally aggressive, low-grade mesenchymal neoplasm of uncertain lineage with a predilection for the lower extremities. We report a 74-year-old woman with an enlarging mass on the right popliteal fossa undergoing FDG PET/CT to characterize its biological activity. Increased accumulation of FDG (SUVmax, 23.0) in the solid component of the tumor was seen. Diagnosis of PHAT was confirmed by examination of the surgical resection specimens. This case showed significant FDG accumulation relative to its pathological low-grade malignant nature.

Rhinolithiasis caused by Actinomyces with a foreign body.

A 39-year-old man presented with chief complaints of epistaxis and pain on the right cheek that lasted for approximately 2 months. A very hard calcified black mass with a foreign body was found in the right inferior nasal meatus. The patient underwent endoscopic endonasal surgery and antimicrobial therapy, which included intravenous injection of Penicillin G 4 million units 6 times/day for 1 week and oral amoxicillin 1500 mg/day for 6 months. Actinomyces species was identified from the calcified foreign body that measured 5 mm in size. There was no recurrence for 1 year after the surgery. Surgical removal and long-term high-dose penicillin for 6 months or longer are necessary because death caused by poor compliance with antibiotics have been reported in previous studies.

Clinicopathological significance of microRNA-21 in extracellular vesicles of pleural lavage fluid of lung adenocarcinoma and its functions inducing the mesothelial to mesenchymal transition.

BACKGROUND: Pre-resection pleural lavage cytology is useful to predict tumor recurrence and the prognosis of lung cancer patients. Recently, extracellular vesicles (EVs) isolated from effusion specimens have come under the spotlight, and several studies showed that microRNA in EVs is associated with prognosis. MicroRNA-21 (miR-21) is a representative onco-microRNA, and miR-21 in EVs (EV-miR-21) promotes cancer dissemination by inducing mesothelial to mesenchymal transition (MMT) in the peritoneal cavity. In this study, we isolated EVs from pleural lavage fluid and focused on EV-miR-21 as a diagnostic factor with a relationship to pleural dissemination. METHODS: The Cancer Genome Atlas dataset comprising of 448 cases of lung adenocarcinoma, tissue microarray of 144 cases of lung adenocarcinoma, and pleural lavage fluid of 41 cases was used to examine miR-21 expression levels. The function of EV-miR-21 was investigated in vitro. RESULTS: The miR-21 expression level in primary sites was associated with a poor prognosis and correlated with pleural invasion of adenocarcinoma. EV-miR-21 levels in pleural lavage fluid were associated with positive cytology and pleural invasion in the primary sites, even in cytology-negative cases. In vitro studies demonstrated that EV-miR-21 induces the MMT. Mesothelial cells in the MMT showed functions similar to cancer-associated fibroblasts, which are an important stromal component in primary sites and disseminated pleural lesions. CONCLUSIONS: EV-miR-21 in pleural lavage fluid is important as a diagnostic and prognostic factor. Moreover, EV-miR-21 induces the MMT, which can form premetastatic niches of dissemination in the pleural cavity.

Imaging spectrum of abnormal subcutaneous and visceral fat distribution.

Adipose tissue plays multiple and complex roles not only in mechanical cushioning and energy storage but also as an important secretory organ that regulates energy balance and homeostasis multilaterally. Fat tissue is categorized into subcutaneous fat tissue (SCAT) or visceral fat tissue (VSA) depending on its distribution, with the two having different metabolic functions. Near-total lack of fat in congenital/acquired generalized lipodystrophy, cachexia, or any other severe malnutrition condition induces severe multi-organ dysfunction due to lack of production of leptin and other adipokines. Increased visceral fat tissue secondary to obesity, hypercortisolism, or multiple symmetric lipomatosis raises the risk of insulin resistance, cardiac complications, and airway or spinal canal stenosis, although the fat distribution pattern differs in each condition. Partial abnormal fat distribution conditions such as HIV/HAART therapy-associated lipodystrophy, familial partial lipodystrophies, and acquired partial lipodystrophy frequently show a mixture of lipoatrophy and lipohypertrophy with metabolic dysfunction. Characteristic imaging features in conditions with local abnormal fat distribution can provide information about a patient's co-existent/unrecognized disease(s), past medical history, or lifestyle. Knowledge of characteristic abnormal fat distribution patterns can contribute to proper and timely therapeutic decision-making and patient education.

Successful surgical management of mesenteric inflammatory veno-occlusive disease.

BACKGROUND: The term "mesenteric inflammatory veno-occlusive disease (MIVOD)" is used to describe an ischemic injury resulting from phlebitis or venulitis that affects the bowel or mesentery in the absence of arteritis. MIVOD is difficult to diagnose because of its rarity and frequent confusion with other diseases. The incidence and etiology of MIVOD remain unclear; only a few cases have been reported. We describe a case of the successful surgical management of a patient with MIVOD with characteristic images. CASE PRESENTATION: A 65-year-old Japanese man visited a hospital with the chief complaint of abdominal pain in January 2018. CT showed edema and thickening of the intestinal wall from the descending colon to the rectum. The patient was admitted to the hospital. Suspected diagnoses were enteritis, ulcerative colitis, amyloidosis, vasculitis, malignant lymphoma, and venous thrombus, but no definitive diagnosis was obtained. The patient was transferred to our hospital for the treatment of stenosis (located from the descending colon to the rectum) and bowel obstruction. An emergency transverse colostomy was performed. The sigmoid colon and mesentery were too rigid and edematous to resect. Colonic hemorrhage occurred 2 weeks after the surgery. With radiology intervention, coiling for the arteriovenous fistula in the descending colon was performed, and hemostasis was obtained. A colonoscopy at 6 months post-surgery showed neither ulceration nor stenosis in the rectum, indicating that the rectum could be preserved in the next surgery. However, severe stenosis in the descending and sigmoid colon remained unchanged. Ten months after the transverse colostomy, we performed a subtotal colectomy and ileorectal anastomosis, and an ileostomy was created. The sigmoid colon and mesentery were not so rigid compared to the first surgery's findings, and we were able to resect intestine and mesentery. Histopathology revealed phlebitis and venulitis, fibrinoid necrosis, and normal arteries, meeting the diagnostic criteria for MIVOD. Postoperatively, the patient showed no recurrence for 8 months. CONCLUSION: Clinicians should consider MIVOD when examining a patient with intestinal ischemia. When MIVOD is suspected, the patient is indicated for surgery based on an accurate diagnosis and good prognosis.

Tumorous CD10 Is More Strongly Related to the Progression of Urothelial Carcinoma than Stromal CD10.

BACKGROUND/AIM: CD10 function in urothelial carcinoma (UC) remains controversial. We previously reported that miR-21 in UC may be a prognostic marker for cancer progression. The aim of this study was to examine the clinicopathological significance of CD10 expression in UC and its relationship with miR-21 expression. MATERIALS AND METHODS: Immunohistochemistry for CD10 was performed on 232 UCs. CD10 expression in TCs and stroma was evaluated respectively, and its association with carcinogenesis and survival was analyzed. RESULTS: High tumorous CD10 was significantly associated with higher tumor stage, histological grade and vessel infiltration, and poorer prognosis, whereas stromal CD10 was significantly associated with younger age, higher tumor stage, and vessel infiltration. On multivariable analysis, CD10 expression in TCs, miR-21 expression in TCs and TS, and tumor stage were independent prognostic factors. CONCLUSION: Tumorous CD10 is more strongly related to progression of UC than stromal CD10 and is an independent factor for UC prognosis.

Mesenchymal Stem Cell Marker Expression in Gastric Cancer Stroma.

BACKGROUND/AIM: Spindle-shaped stromal cells of tumors are derived from various cellular origins, including mesenchymal stem cells (MSCs). MSCs express CD73, CD90 and CD105 antigens. Herein, the aim was to investigate the association between the expression of specific MSC markers in gastric cancer stromal cells and the clinicopathological features of the disease. MATERIALS AND METHODS: The expression of CD73, CD90 and CD105 in spindle-shaped cancer stromal cells was studied by immunohistochemistry in tissue arrays containing 546 gastric cancer cases. Univariate and multivariate analyses were performed to evaluate the association of MSC marker expression with clinicopathological variables. RESULTS: Spindle-shaped cancer stromal cells expressing the MSC markers CD73, CD90 or CD105 were associated with larger tumor size, advanced cancer, venous infiltration, lymphatic infiltration, and lymph node metastasis. Statistical analysis demonstrated that the presence of CD105-positive spindle cells was an independent prognostic factor of advanced cancer, lymph node metastasis and EBV infection in multivariate analysis. CONCLUSION: Spindle-shaped gastric cancer stromal cells expressing CD73, CD90 or CD105 are involved in disease progression, and among them, CD105-positive cells are strongly associated with poor prognosis.