Tenosynovial giant cell tumors of digits: MRI differentiation between localized types and diffuse types with pathology correlation.

OBJECTIVE: To compare the MRI findings between the localized- and diffuse-type tenosynovial giant cell tumors (TSGCTs) of digits with pathology correlation. METHODS: Twenty-eight patients with newly diagnosed TSGCTs of digits (22 localized and 6 diffuse types) who underwent preoperative MRI and surgical excision were included from Jan. 2015 to September 2021. MRI findings regarding nodularity, margins, morphology of hypointensity with pathology correlation, and disease extent (bone erosion, articular involvement, muscle involvement, tendon destruction, and neurovascular encasement) were assessed. RESULTS: Diffuse type was significantly larger (P = 0.006), more multinodular on both MRI and pathology (P = 0.038, both) with significant agreement, and infiltrative on both MRI and pathology (P < 0.001, both) with substantial agreement, and showed central granular on MRI and strong hemosiderin deposition on pathology (P = 0.022 and P = 0.021) with moderate agreement than localized type. Localized type showed significantly more frequent peripheral capsules on both MRI and pathology (P < 0.001, both) with moderate agreement than diffuse type. However, the septum on both MRI and pathology showed no statistically significant difference between the two groups (P = 0.529 and P = 0.372) without significant agreement. The disease extent was more severe in the diffuse type than the localized type regarding articular involvement (P < 0.001), muscle involvement (P < 0.001), and tendon destruction (P = 0.010). No statistically significant differences were found between the two groups regarding bone erosion (P = 0.196) or neurovascular bundle encasement (P = 0.165). CONCLUSIONS: Diffuse-type TSGCTs of digits presented as locally aggressive lesions with larger, multinodular, infiltrative masses exhibiting stronger hemosiderin deposition and more severe disease extents of articular, muscle, and tendon involvement than the localized type.

Benign peripheral nerve sheath tumor of digit versus major-nerve: Comparison of MRI findings.

OBJECTIVE: To compare the symptoms and magnetic resonance imaging (MRI) findings between digital peripheral nerve sheath tumor (PNST) and major-nerve PNST. METHODS: A total 36 cases with benign PNSTs (16 digital, 20 major-nerve) were enrolled. Chief complaint and Tinel sign were reviewed. Five classic MRI features of PNST, the signal intensity (SI), the enhancement, and the shape of tumor were evaluated on MRI. RESULTS: Half of each group showed tenderness. Tinel sign was less frequent in digital PNST (12.5%) than major-nerve PNST (95.0%, P < 0.001). Split fat sign, entering and exiting nerve, target sign, and thin hyperintense rim were only observed in major-nerve PNST (P = <0.001, <0.001, 0.492, and 0.002, respectively). Fascicular sign was found in digital PNSTs (31.3%), but more frequent in major-nerve PNST (P < 0.001). In digital PNSTs, mild hyperintense SIs (56.2%) on T1-weighted images (T1-WI) was noted, but none in major-nerve PNST (P < 0.001). Both groups showed hyperintense SIs on T2-WI (P = 0.371). Homogeneity on T2-WI was noted in 43.8% of digital PNSTs, but none in major-nerve PNSTs (P = 0.004). Both groups showed heterogeneous enhancement (P = 0.066), but four (25%) digital PNSTs showed homogeneous enhancement. Lobulated shape was noted in 50% of digital PNSTs but none of major-nerve PNSTs (P = 0.001). Digital nerve was involved at 81.3% of digital PNSTs. Three foot cases showed unusual manifestations: bone destruction, skin thickening, and subungual location. CONCLUSION: In digital PNSTs, Tinel sign is not commonly found and classic MRI findings is insufficient. In addition, some digital PNSTs show different SI and enhancement from major-nerve PNSTs. However, digital soft tissue tumor involving digital neurovascular bundle and especially representing a fascicular sign should be considered the possibility of a digital PNST.

Intramuscular peripheral nerve sheath tumors: schwannoma, ancient schwannoma, and neurofibroma.

PURPOSE: To analyze the prevalence of classic magnetic resonance imaging (MRI) findings of intramuscular peripheral nerve sheath tumors (PNSTs), including schwannoma, ancient schwannoma, and neurofibroma. METHOD: Thirty pathologically confirmed benign intramuscular PNSTs (24 schwannomas, 3 ancient schwannomas, and 3 neurofibromas) were retrospectively reviewed. Classic MRI findings of PNSTs including split fat sign, fascicular sign, target sign, entering and exiting nerve, and thin hyperintense rim were assessed for each intramuscular PNST. Denervation change of the affected muscle was also assessed. In ancient schwannoma and neurofibroma, the signal intensity (SI) and enhancement pattern were analyzed. RESULTS: All intramuscular schwannomas revealed two more classic MRI findings. Eight of the 24 intramuscular schwannomas revealed affected muscle denervation change. All intramuscular ancient schwannomas showed only split fat sign. All intramuscular ancient schwannomas showed denervation change of the associated muscle. All intramuscular neurofibroma showed split fat sign and one case with target sign was detected. Ancient schwannomas were isointense SI on T1-weighted image (T1WI) and one case had hyperintense foci. They showed heterogeneously hyperintense SI on T2-weighted image (T2WI) with heterogeneous enhancement. Neurofibromas were isointense SI (2/3) and slight hyperintense SI (1/3) on T1WI and heterogeneously hyperintense SI on T2WI with heterogeneous enhancement. One ancient schwannoma showed conglomerated calcifications. CONCLUSIONS: Intramuscular schwannomas were easily diagnosed based on MRI. In the case of intramuscular ancient schwannoma and neurofibroma with only split fat sign among the classic MRI findings, they might be distinguished from other intramuscular soft tissue tumors based on muscle denervation change or typical crescent split fat sign.

Clinical Significance of Revised Banff Criteria in the Diagnosis of Antibody-Mediated Rejection.

BACKGROUND: The diagnostic criteria of antibody-mediated rejection (ABMR) has been significantly changed since Banff 2013. The most important revision was adopting microvascular inflammation (MVI) as immunopathologic evidence for ABMR even in C4d-negative cases. In this study, we retrospectively reviewed previous allograft biopsy results and evaluated the impact of this change. METHODS: We reviewed results of 536 renal allograft biopsies at Severance Hospital during 2011 to 2013, which were diagnosed according to the Banff 2009 criteria. All biopsy results were reassessed according to the Banff 2017 criteria. RESULTS: According to the Banff 2009 criteria, antibody-mediated changes were observed in 48 cases out of the 536 allograft biopsies (9.0%). According to the Banff 2017 criteria, 28 additional cases (5.2%) were reclassified as antibody-mediated changes. Twenty-six of these cases were C4d-negative ABMR. The most frequent diagnostic finding in these cases was MVI comprising glomerulitis and peritubular capillaritis. Donor-specific antibodies were investigated in 14 of these cases, which revealed positive results in 12 cases. CONCLUSION: The incidence rate of ABMR has increased after the recent revision of the Banff criteria. The MVI in C4d-negative ABMR cases is the major cause for this increase.

The value of phosphohistone H3 as a proliferation marker for evaluating invasive breast cancers: A comparative study with Ki67.

BACKGROUND: Established measurements of proliferation in breast cancer are Ki67 and mitotic-activity-index (MAI), with problems in reproducibility and prognostic accuracy. Phosphohistone H3 (PHH3), a relatively novel IHC marker is specific for mitosis with good reproducibility. We hypothesized that PHH3 would be more reproducible and better represent proliferation than Ki67. RESULTS: PHH3 identified easily-missed mitosis by MAI, as demonstrated by upgrading M grade at diagnosis (n = 29/218, evenly distributed). PHH3 accurately found hot-spots, supported by mitotic count agreement between low-power and 10HPFs (R2 = 0.999; P = 0.001). PHH3 was more reproducible than Ki67, measured by five-rater inter-class correlation coefficient (0.904 > 0.712; P = 0.008). Finally, despite a relatively short follow-up (median 46 months; 7 recurrences) PHH3 was the only variable correlated with disease-free survival (P = 0.043), while all other conventional clinicopathologic variables, including Ki67 (P = 0.356), did not. MATERIALS AND METHODS: We compared Ki67 and PHH3 for 218 breast cancer surgical cases diagnosed from 2012 to 2013 at Severance hospital. The most representative invasive breast cancer surgical slides were immunohistochemically stained for Ki67 and PHH3. CONCLUSIONS: Poor reproducibility and inadequate representation of proliferation of Ki67 and MAI may be improved by PHH3, allowing better accuracy in breast cancer diagnostics.

Successful kidney transplantation across a positive complement-dependent cytotoxicity crossmatch by using C1q assay-directed, bortezomib-assisted desensitization: A case report.

RATIONALE: Human leukocyte antigen (HLA) is the major immunologic barrier in kidney transplantation (KT). Various desensitization protocols to overcome the HLA barrier have increased the opportunity for transplantation in sensitized patients. In addition, technological advances in solid-phase assays have permitted more comprehensive assessment of donor-specific antibodies. Although various desensitization therapies and immunologic techniques have been developed, the final transplantation decision is still based on the classic complement-dependent cytotoxicity (CDC) crossmatch (XM) technique. Some patients who fail to achieve negative XM have lost their transplant opportunities, even after receiving sufficient desensitization therapies. PATIENT CONCERNS: A 57-year-old male with end-stage renal disease secondary to chronic glomerulonephritis was scheduled to have a second transplant from his son, but CDC XM was positive. DIAGNOSES: Initial CDC XM (Initial T-AHG 1:32) and flow-cytometry XM were positive. Anti-HLA-B59 donor specific antibody was detected by Luminex single antigen assay. INTERVENTIONS: Herein, we report a successful case of KT across a positive CDC XM (T-AHG 1:8 at the time of transplantation) by using C1q assay-directed, bortezomib-assisted desensitization. After confirming a negative conversion in the C1q donor-specific antibody, we decided to perform KT accepting a positive AHG-CDC XM of 1:8 at the time of transplantation. OUTCOMES: The posttransplant course was uneventful and a protocol biopsy at 3 months showed no evidence of rejection. The patient had excellent graft function at 12 months posttransplant. LESSONS: The results of XM test and solid-phase assay should be interpreted in the context of the individual patient.

[Hepatobronchial Fistula and Lung Abscess after Transarterial Chemoembolization].

Transarterial chemoembolization (TACE) is a common treatment modality to locally manage hepatocellular carcinoma. Liver abscess and bile duct injury are common complications of TACE. However, hepatobronchial fistula is a rare complication. Herein, we report a case of lung abscess due to hepatobronchial fistula after TACE. A 67-year-old man, who had underwent TACE 6 months ago, presented cough and bile-colored sputum. He was diagnosed with lung abscess and hepatobronchial fistula. We performed endoscopic retrograde cholangiopancreatography; however, there was no improvement in his symptoms. Thereafter, partial hepatectomy and repair of fistula were successively conducted.

ACTH-producing neuroendocrine tumor of the pancreas: a case report and literature review.

Tumors that arise from the endocrine pancreas, or the islets of pancreas, are called pancreatic neuroendocrine tumors (NETs). Pancreatic NET have an incidence of <0.1 per one million persons, and can lead to secretion of ectopic adrenocorticotropic hormone (ACTH). Herein, we presented a case of patient with Cushing's syndrome as a result of ACTH-producing pancreatic NET, who underwent successful laparoscopic distal pancreatosplenectomy. A 40-year-old Korean female patient with ophthalmologic discomfort, osteoporosis, and unexplained hypokalemia was admitted to our hospital. Under the suspicion of ACTH producing pancreatic NET after the diagnostic workup, we decided to perform surgical resection. Laparoscopic distal pancreatosplenectomy was performed; and the pathological examination revealed a 1.5 cm-sized grade 2 neuroendocrine tumor of the pancreas, which was encapsulated within the pancreatic parenchyma. After the operation, the patient no longer displayed cushingoid features. ACTH-producing pancreatic NET is rare, but can be one of the causes of Cushing's syndrome. Surgical resection is a feasible option in treating ACTH-producing pancreatic NET.