The classification of atypical adipocytic neoplasms with spindle cell features remains challenging. To better define this category of low-grade lipomatous neoplasms, we present herein the clinical, histologic, and immunohistochemical characteristics of a large series of 232 atypical spindle cell lipomatous tumors. The lesions affected 140 males and 92 females, at an average age of 54 years (range, 6 to 87 y), clinically presenting as a persistent or enlarging mass with a median size of 5 cm. The anatomic distribution of the tumors was wide, predominating in the limbs and limb girdles (147 cases, 63%), mainly in the hands and feet (17% and 11%, respectively), with equal distribution between subcutaneous and deeper locations. Microscopic examination revealed a spectrum of histologic appearances. All cases consisted of a poorly marginated proliferation of mildly atypical spindle cells set in a fibrous or myxoid stroma, with a variably prominent admixed adipocytic component showing variation in adipocyte size and scattered nuclear atypia, frequently with univacuolated or multivacuolated lipoblasts. Tumor cellularity and the relative proportion of the different components were very variable. Tumor margins were often ill defined with invasion into surrounding tissues. Two tumors showed morphologic features reminiscent of dedifferentiation. By immunohistochemistry, the neoplastic spindle cells expressed CD34 (64%), S100 protein (40%) and, less frequently, desmin (23%). Expression of Rb was lost in 57% of cases examined. MDM2 and CDK4 were never coexpressed and FISH for MDM2 amplification was consistently negative, highlighting critical biological differences from atypical lipomatous tumor/dedifferentiated liposarcoma. The morphologic differential diagnosis of atypical spindle cell lipomatous tumor is broad, and includes spindle cell lipoma, diffuse neurofibroma, mammary-type myofibroblastoma, dermatofibrosarcoma protuberans, fat-forming solitary fibrous tumor, and morphologically low-grade malignant peripheral nerve sheath tumor. Most patients underwent surgical excision of the primary mass. With a median follow-up of 4 years (range, 1 mo to 20 y), 87% of patients (63/72) were alive with no evidence of recurrence or metastatic disease. Local recurrence of the tumor was observed in 12% of patients (9 out of 72, multiple in 3 of them) at intervals between 6 months and 17 years after resection of the primary tumor. None of the patients developed tumor metastasis or died of disease. Identification of the neoplastic adipocytic component admixed with spindle cells, and recognition of the range of histologic appearances are key for the diagnosis of atypical spindle cell lipomatous tumor. Whereas the risk of metastatic dissemination is minimal, there is a non-negligible risk for local recurrence (13%) which warrants surgical resection with clear margins whenever feasible.

Atopic dermatitis (AD) is a chronic and persistent inflammatory skin disease characterized by eczematous lesions and itching, and it has become a serious health problem. However, the common clinical treatments provide limited relief and are accompanied by adverse effects. Therefore, there is a need to develop novel and effective therapies to treat AD. Neferine is a small molecule compound isolated from the green embryo of the mature seeds of lotus (Nelumbo nucifera). It has a bisbenzylisoquinoline alkaloid structure. Relevant studies have shown that neferine has many pharmacological and biological activities, including anti-inflammatory, anti-thrombotic, and anti-diabetic activities. However, there are very few studies on neferine in the skin, especially the related effects on inflammatory skin diseases. In this study, we proved that it has the potential to be used in the treatment of atopic dermatitis. Through in vitro studies, we found that neferine inhibited the expression of cytokines and chemokines in TNF-α/IFN-γ-stimulated human keratinocyte (HaCaT) cells, and it reduced the phosphorylation of MAPK and the NF-κB signaling pathway. Through in vivo experiments, we used 2,4-dinitrochlorobenzene (DNCB) to induce atopic dermatitis-like skin inflammation in a mouse model. Our results show that neferine significantly decreased the skin barrier damage, scratching responses, and epidermal hyperplasia induced by DNCB. It significantly decreased transepidermal water loss (TEWL), erythema, blood flow, and ear thickness and increased surface skin hydration. Moreover, it also inhibited the expression of cytokines and the activation of signaling pathways. These results indicate that neferine has good potential as an alternative medicine for the treatment of atopic dermatitis or other skin-related inflammatory diseases.

DOG1 (discovered on GIST 1), known also as TMEM16A and ANO1, has emerged in recent years as a promising biomarker for gastrointestinal stromal tumors (GIST). It was originally discovered through microarray expression profiling analysis as gene that is highly expressed in GIST, and subsequent immunohistochemical studies have shown its use in its diagnosis. The results from several series have shown a high overall sensitivity and specificity for DOG1 in the detection of GISTs and about 6% of GISTs overall exhibiting a DOG1+/KIT-immunoprofile. DOG1 antibodies are more sensitive than KIT antibodies in detecting tumors of gastric origin, tumors with epithelioid morphology, and tumors harboring PDGFRA mutation. Furthermore, DOG1 immunoreactivity is rarely observed in other mesenchymal and nonmesenchymal tumor types. These results support the use of DOG1 as a diagnostic biomarker for GIST. When used in combination with KIT, this panel of diagnostic biomarkers can help pathologists and clinicians to identify more patients who may benefit from targeted therapies.

Sorafenib has substantial clinical activity as third- or fourth-line treatment of imatinib- and sunitinib-resistant gastrointestinal stromal tumors (GIST). Because sorafenib targets both angiogenesis-related kinases (VEGFR) and the pathogenetic kinases found in GIST (KIT or PDGFRA), the molecular basis for sorafenib efficacy in this setting remains unknown. We sought to determine the spectrum of activity of sorafenib against different mutant kinases associated with drug-sensitive and drug-resistant GIST. We compared the activity of imatinib and sorafenib against transiently expressed mutant forms of KIT and PDGFRA, including various secondary mutations that have been identified in imatinib-resistant or sunitinib-resistant GISTs. We also examined these drugs against four GIST cell lines, three of which are imatinib resistant. In our in vitro studies, we determined that sorafenib inhibited imatinib-resistant mutations in exons encoding the ATP/drug-binding pocket and in exons encoding the activation loop, with the exception of substitutions at KIT codon D816 and PDGFRA codon 842. Notably our data indicate that sorafenib is more effective than imatinib or sunitinib for inhibiting the kinase activity of drug-resistant KIT mutants (as assessed by biochemical IC₅₀). We hypothesize that a major determinant of the efficacy of sorafenib for treatment of advanced GIST is the activity of this agent against KIT or PDGFRA-mutant kinases. These results have implications for the further development of treatments for drug-resistant GIST. Mol Cancer Ther; 11(8); 1770–80. ©2012 AACR.