Citations

We report a case of low‐grade fibromyxoid sarcoma arising within the median nerve. A 31‐year‐old woman presented with symptoms of carpal tunnel syndrome and an enlarging mass in her right palm over 1 year. MRI demonstrated a mass associated with the right median nerve with solid and cystic components. At surgery, the mass was located within the epineurium, could be bluntly dissected from the nerve fascicles, and was suspected to be a schwannoma. A 3.4 cm, tan‐pink, glistening, smooth, homogenous mass was submitted to pathology. Microscopically, the tumor was a solid and cystic circumscribed nodule with a dense fibrous pseudocapsule. The tumor cells were uniformly bland and spindle‐shaped, with small, hyperchromatic oval nuclei and were embedded in an alternating fibrous and myxoid stroma with a prominent curvilinear vasculature and perivascular sclerosis. The differential diagnosis for this lesion included myxoid neurofibroma, schwannoma, soft tissue perineurioma, low‐grade malignant peripheral nerve sheath tumor and low‐grade fibromyxoid sarcoma. The tumor cells expressed MUC4, GLUT‐1, and vimentin and were negative for S‐100 protein, epithelial membrane antigen, smooth muscle actin, desmin, claudin‐1, neurofilament and SOX10. Fluorescence in situ hybridization, with a break‐apart probe strategy, demonstrated FUS rearrangement, consistent in this morphological context with the low‐grade fibromyxoid sarcoma‐associated FUS‐CREB3L2 or FUS‐CREB3L1 fusions. Low‐grade fibromyxoid sarcoma is exceptionally rare in the peripheral nerve, with only a single previously reported case. Nonetheless, as our case illustrates, this entity must be included in the differential diagnosis of unusual intraneural mesenchymal tumors. As in all other locations, intraneural low‐grade fibromyxoid sarcomas should be excised with negative margins. Patients with this disease require long‐term clinical follow‐up, given this tumor's propensity for very late distant metastases to the lungs and other sites.

AbstractBackground and objectiveIdiopathic pulmonary fibrosis (IPF) is increasingly diagnosed by clinical and computed tomography (CT) criteria; however, surgical lung biopsy (SLB) may still be required in patients who lack definite CT features of usual interstitial pneumonia (UIP). We reviewed a cohort of elderly patients who underwent SLB, to evaluate the benefit of SLB in diagnosing idiopathic interstitial pneumonia (IIP).MethodsWe searched the pathology records of Mayo Clinic for ambulatory patients at least 75 years old, who underwent SLB between 2000 and 2012 for indeterminate IIP. Histologic slides were reviewed and clinical data were extracted from the record.ResultsA total of 55 patients (35 male) were enrolled. Median (interquartile range) age was 77 (76–80) years. Forced vital capacity was 70 (61–76)% and diffusing capacity of the lungs for carbon monoxide was 48 (42–54)% of predicted. In total, 37 (67%) patients had IPF, including 61% of those with HRCT findings inconsistent with UIP. Thirty‐day mortality was 10% and 90‐day mortality was 15%.ConclusionThe high mortality rate of SLB complicates the risk–benefit analysis in elderly patients with IIP. The expected value of the SLB is probably highest when the HRCT features are inconsistent with UIP, due to the frequent (39%) retrieval of patterns other than UIP.

AbstractBackgroundThe benign and malignant patterns of acral melanocytic naevi (AMN) and acral melanomas (AM) have been defined in a series of retrospective studies. A three‐step algorithm was developed to determine when to biopsy acral melanocytic lesions. This algorithm has only been applied to a Japanese population.ObjectivesOur study aimed to review the current management strategy of acral melanocytic lesions and to investigate the utility of the three‐step algorithm in a predominately Caucasian cohort.MethodsA retrospective search of the pathology and image databases at Mayo Clinic was performed between the years 2006 and 2016. Only cases located on a volar surface with dermoscopic images were included. Two dermatologists reviewed all dermoscopic images and assigned a global dermoscopic pattern. Clinical and follow‐up data were gathered by chart review. All lesions with known diameter and pathological diagnosis were used for the three‐step algorithm.ResultsRegular fibrillar and ridge patterns were more likely to be biopsied (P = 0.01). The majority of AMN (58.1%) and AM (60%) biopsied were due to physician‐deemed concerning dermoscopic patterns. 39.2% of these cases were parallel furrow, lattice‐like or regular fibrillar. When patients were asked to follow‐up within a 3‐ to 6‐month period, only 16.7% of the patients returned within that interval. The three‐step algorithm would have correctly identified four of five AM for biopsy, missing a 6 mm, multicomponent, invasive melanoma.ConclusionWe found one major educational gap in the recognition of low‐risk lesions with high rates of biopsy of the fibrillary pattern. Recognizing low‐risk dermoscopic patterns could reduce the rate of biopsy of AMN by 23.3%. We identified two major practice gaps, poor patient compliance with follow‐up and the potential insensitivity of the three‐step algorithm to small multicomponent acral melanocytic lesions.

Adult gliomas are aggressive brain tumours associated with low patient survival rates and limited life expectancy. The most important hallmark of this type of tumour is its invasive behaviour, characterized by a markedly phenotypic plasticity, infiltrative tumour morphologies and the ability of malignant progression from low- to high-grade tumour types. Indeed, the widespread infiltration of healthy brain tissue by glioma cells is largely responsible for poor prognosis and the difficulty of finding curative therapies. Meanwhile, mathematical models have been established to analyse potential mechanisms of glioma invasion. In this review, we start with a brief introduction to current biological knowledge about glioma invasion, and then critically review and highlight future challenges for mathematical models of glioma invasion.

AbstractTrichothiodystrophy is a rare autosomal recessive disorder resulting in a broad range of systemic abnormalities. Polarizing microscopy of the hair reveals the pathognomic “tiger tail” of alternating light and dark bands, but the need for a microscope prevents rapid bedside diagnosis. We describe a new technique for the bedside diagnosis of trichothiodystrophy using a handheld polarizing dermatoscope, precluding the need for microscopic examination.

The use of venovenous extracorporeal membrane oxygenation (VV-ECMO) has traditionally been limited to a narrow set of clinical circumstances, such as acute hypoxic respiratory failure, submassive pulmonary embolism, and cardiopulmonary collapse. Within the pediatric population, there have been cases of VV-ECMO in the context of extrinsic airway compression by a mediastinal mass, typically in the setting of either a lymphoma or germ cell tumors. However, the use of VV-ECMO for adults with extrinsic airway compression is comparatively limited. More specifically, VV-ECMO has been used as a bridge for tracheal reconstruction in both children and adults. Although, it has not been used in adults in the context of palliative endobronchial stent placement. We present a case of a 49-year-old woman with refractory multiple myeloma and extramedullary plasmacytoma presenting with acute hypoxic respiratory failure from extrinsic airway compression by a mediastinal plasmacytoma. We were able to use VV-ECMO to assist with endobronchial stent placement, followed by radiation therapy, and ultimately hospital discharge. In this article, we also review the literature surrounding VV-ECMO for extrinsic airway compression.