Whole exome sequencing of a gut-associated lymphoid tissue neoplasm points to precursor or early form of sporadic colon carcinoma.

Gut-associated lymphoid tissue (GALT) carcinoma is a colorectal neoplasm characterized by cystically dilated neoplastic glands that extend into prominent, well-circumscribed submucosal lymphoid tissue. Although often subtle, lamina propria between and around the neoplastic glands (identified by plasma cells, scattered eosinophils, etc.) is frequent in cases with classic morphology, arguing (at least in such cases) in favor of adenoma extending into lymphoglandular complexes rather than true invasive carcinoma. Some have postulated that the tumor arises from M-cells, specialized epithelial cells overlying GALT, and others have suggested it represents a unique pathway to carcinoma, specific to the environmental conditions of epithelium overlying lymphoid tissue. Although both hypotheses are intriguing, definitive phenotypic and genetic support is currently lacking. To address these possibilities, we undertook whole exome sequencing and immunohistochemical characterization of a GALT neoplasm recently identified on our clinical service. We discovered well-known mutations in both APC and KRAS, as well as mutations in several Wnt pathway components (MED12, BCL9L, RFX4, DACT3). No immunohistochemical expression of GP2, a marker of M-cell differentiation, was identified. Expression of CDX2, SATB2, and the DNA mismatch repair proteins was observed, while expression of both CK7 and CK20 was absent. No PD-L1 expression was present on tumor cells, but PD-L1 expression was noted in a subset of tumor-adjacent mononuclear cells. Overall, the findings suggest that GALT neoplasms, although morphologically distinct, may be a precursor or early form of typical sporadic colon carcinoma.

Surgical Excision of a Symptomatic Thoracic Nerve Root Perineural Cyst Resulting in Complete Resolution of Symptoms: A Case Report.

Tarlov (perineural) cysts of the nerve root are common and usually incidental findings during magnetic resonance imaging (MRI) of the lumbosacral spine. There are a few case reports where symptomatic thoracic perineural cysts have been described in the literature. We report a case of a high thoracic nerve root perineural cyst that failed conservative therapy, requiring surgical intervention. Our patient presented with radicular symptoms involving the left hand. Imaging workup revealed a cystic lesion of the left T1 nerve root at the level of the foramen. Surgical resection resulted in significant improvement in patient symptoms, and pathology revealed a perineural cyst. We conclude that a thoracic perineural (Tarlov) cyst can be symptomatic by causing nerve root compression and can be mistaken as a nerve root sheath tumor on imaging. Surgical treatment can be curative.

Fungal brain abscess caused by "Black Mold" (Cladophialophora bantiana) - A case report of successful treatment with an emphasis on how fungal brain abscess may be different from bacterial brain abscess.

BACKGROUND: Central nervous system infection with Cladophialophora bantiana (Black Mold) is rare. It carries a high mortality rate, that is more than 70%, despite multimodal therapy. CASE DESCRIPTION: We present a rare case of "black mold" fungal brain abscess that was successfully treated with good patient outcome. The case is unusual because there were two fungal brain abscesses located bilaterally symmetrically in the mesial frontal lobes, and the response to different treatment strategies was well documented by over 25 magnetic resonance imaging (MRI) scans. Initial attempts to treat these lesions by repeated surgical excision and systemic amphotericin B was followed by continued growth rather than resolution. We realized that the application of treatment principles learned from bacterial brain abscess may not transpose intuitively to the treatment of fungal brain abscess. Therefore, a new treatment strategy was adopted that avoided further attempts at resection in favor of long-term oral voriconazole and repeated intracavitary aspiration and instillation of amphotericin B on an outpatient basis. Without further resection, the lesions stabilized and the aspirates eventually sterilized, however, the enhancing capsule never resolved on MRI scans. All treatment was stopped after 1 year. The apparently sterilized lesions have been followed for an additional 3 years without further growth, and the patient remains functionally, intellectually, and behaviorally normal. CONCLUSION: We conclude that, in the case of fungal abscess, it may be preferable to sterilize the lesion in situ rather than attempting to achieve resolution on imaging studies by repeated surgical resection of the capsule which can be counterproductive. This strategy accepts that the capsule may be important to the patient's immune defense against the fungus. Helping that defense barrier with intracapsular and systemic antifungal agents, rather than capsular removal, may be the better strategy for patients in whom early aggressive resection has failed. The basis for the apparent differences in the response of fungal versus bacterial brain abscess to surgical resection is discussed in the light of pathological findings from this and other cases.

Strong NFκB Expression is Associated With High-grade Dysplasia in Barrett's Esophagus.

Nuclear factor kappa B (NFκB) is a transcription factor that regulates the activation of genes involved in proinflammatory response and growth. In this study, we utilized immunohistochemical stains for 2 of the NFκB molecules (RELA and NFκB-1) to evaluate the expression of NFκB in Barrett's esophagus (BE). Forty-three cases of BE [17 cases with no dysplasia, 16 cases with low-grade dysplasia (LGD), and 10 cases with high-grade dysplasia (HGD)], 10 normal esophageal biopsies, and 9 cases of esophageal adenocarcinoma were evaluated. Expression of NFκB-1 and RELA did not occur in normal esophageal squamous mucosa. BE without dysplasia showed weak expression of RELA and NFκB-1 in 35% and 65% of cases, respectively. BE with LGD showed weak expression of RELA and NFκB-1 in 50% and 75% of cases, respectively. Strong expression of RELA and NFκB-1 did not occur in BE without dysplasia or with LGD. BE with HGD showed strong expression of RELA and NFκB-1 in 80% and 90% of cases, respectively. All cases of adenocarcinoma showed strong expression of both RELA and NFκB-1. There was a progressive increase in staining intensity of RELA and NFκB-1 along the metaplasia-dysplasia-adenocarcinoma pathway. Strong expression of NFκB is associated with HGD and adenocarcinoma (P<0.0001). We showed that strong expression of NFκB-1 and RELA correlates highly with BE with HGD and adenocarcinoma.

Resveratrol sensitizes acute myelogenous leukemia cells to histone deacetylase inhibitors through reactive oxygen species-mediated activation of the extrinsic apoptotic pathway.

Histone deacetylase inhibitors (HDACIs) activate the prosurvival nuclear factor-κB (NF-κB) pathway by hyperacetylating RelA/p65, whereas the chemopreventive agent resveratrol inhibits NF-κB by activating the class III histone deacetylase Sirt1. Interactions between resveratrol and pan-HDACIs (vorinostat and panobinostat) were examined in human acute myelogenous leukemia (AML) cells. Pharmacologically achievable resveratrol concentrations (25-50 µM) synergistically potentiated HDACI lethality in AML cell lines and primary AML blasts. Resveratrol antagonized RelA acetylation and NF-κB activation in HDACI-treated cells. However, short hairpin RNA Sirt1 knockdown failed to modify HDACI sensitivity, which suggests that factors other than or in addition to Sirt1 activation contribute to resveratrol/HDACI interactions. These interactions were associated with death receptor 5 (DR5) up-regulation and caspase-8 activation, whereas cells expressing dominant-negative caspase-8 were substantially protected from resveratrol/HDACI treatment, which suggests a significant functional role for the extrinsic apoptotic pathway in lethality. Exposure to resveratrol with HDACI induced sustained reactive oxygen species (ROS) generation, which was accompanied by increased levels of DNA double-strand breaks, as reflected in γH2A.X and comet assays. The free radical scavenger Mn(III)tetrakis(4-benzoic acid)porphyrin chloride blocked ROS generation, DR5 up-regulation, caspase-8 activation, DNA damage, and apoptosis, which indicates a primary role for oxidative injury in lethality. Analyses of cell-cycle progression and 5-ethynyl-2'-deoxyuridine incorporation through flow cytometry revealed that resveratrol induced S-phase accumulation; this effect was abrogated by HDACI coadministration, which suggests that cells undergoing DNA synthesis may be particularly vulnerable to HDACI lethality. Collectively, these findings indicate that resveratrol interacts synergistically with HDACIs in AML cells through multiple ROS-dependent actions, including death receptor up-regulation, extrinsic apoptotic pathway activation, and DNA damage induction. They also raise the possibility that S-phase cells may be particularly susceptible to these actions.