Aggressive Case Research Articles

…and this is my voice: autopathophonography and the politics of variable voice

This essay describes the production and theoretical context of an audio work entitled “…and this is my voice.” In May and June 2010, I took recordings of my voice while on the way into external beam radiation treatments for an aggressive case of papillary thyroid cancer in my neck. I then used these recordings as the raw material for the work. This essay provides full documentation of the production process for those who may want or need something beyond the original audio work to engage with it fully, as well as a theoretical discussion of the ideology of vocal ability: the belief that voices are expressions of subjects’ inner states and abilities.
 
 Work available at: https://jonathansterne.bandcamp.com/track/and-this-is-my-voice

S1920 An Aggressive Case of Colorectal Adenocarcinoma with Neuroendocrine Features

S1920 An Aggressive Case of Colorectal Adenocarcinoma with Neuroendocrine Features

Benign COVID-19 in an aggressive case of aquaporin-4 Neuromyelitis optica treated with tocilizumab

Neuromyelitis optica (NMO) with antibodies (Abs) against aquaporin-4 (AQP4) is an astrocytopathy with severe spinal attacks resulting in mobility impairment. Relapse prevention is mandatory with immunosuppressants or anti-CD20 monoclonal Abs. Aggressive AQP4-Ab NMO could benefit by blocking the interleukin 6 (IL6) pathways with Tocilizumab. This IL6 inhibitor improved patient outcome in severe COVID-19 pneumonia.

Multiple non-syndromic basal cell carcinoma with the chest as primary site and lung metastases: A rare case.

Basal cell carcinoma (BCC) is the most commonly diagnosed cancer in humans, usually affecting elderly Caucasian men and skin regions mostly exposed to the sun, that rarely metastasizes. We report an unusual and aggressive case of multiple, non-syndromic metastatic BCC with an uncommon primary site in the chest and pulmonary metastases, treated successfully with surgery and vismodegib. A 51-year-old woman presented with a large pigmentary lesion of the chest, close to the sternum. She had the lesion for > 25 years and lately noticed multiple facial lesions. The diagnosis of multiple BCC was suspected and a punch biopsy of the primary lesion was performed. Diagnosis was confirmed by immunohistochemistry (BerEp4+, EMA− phenotype). After excision, staging with a thorax computed tomography scan revealed metastatic micro-nodules in the left lung, confirmed histologically after video-assisted thoracic surgical biopsy. Adjuvant chemotherapy with vismodegib was proposed and administered. At 30 days follow-up, thorax computed tomography scan was unaltered and her facial lesions showed significant regression. Although prognosis remains poor, early diagnosis and prompt management complimented by novel biological agents, like vismodegib, targeting disease pathogenesis, seems to bring promising results.

Case Report of Aggressive T-Cell Large Granular Lymphocytic Leukemia

Large granular lymphocyte (LGL) leukemia is a spectrum of rare lymphoproliferative disorders. Two entities are reported: indolent T-cell LGL leukemia and aggressive NK cell leukemia. However, a review of the literature identified cases of aggressive T-cell LGL. Considering this unusual and rare clinical presentation, we are reporting a case of aggressive T-cell LGL leukemia.A 53-yo man presented in May 2014 with a one year history of constitutional symptoms, splenomegaly, mild lymphocytosis and a pancytopenia (hemoglobin 105 g/L, neutrophils 0,5 x 109 /L and platelets 80 x 109 /L). He had similar symptoms at the age of 24 that resolved without further investigation. Bone marrow evaluation revealed a massive infiltration by small to medium sized lymphocytes with irregular nucleus CD3 +, CD4 -, CD7 -, CD8 +, CD25 -, CD33 -, CD34 -, CD56 -, CD57 -, TCRαβ+. HTLV-1 serology was negative. His pancytopenia did not improve with 3 cycles of CHOP followed by 4 cycles of ESHAP. In January 2015, indolent T LGL was finally retained. The patient was observed up to July 2015 where methotrexate was begun because of frequent infections and symptomatic splenomegaly. A splenectomy was performed in January 2016 due to a toxicity to methotrexate and persistent symptoms from splenomegaly. Pathology report showed a splenic and lymph node infiltration by mature T CD8+ lymphocytes supporting the T LGL diagnosis. Post splenectomy, cytopenia improved and progressed in June 2016 with a lymphocytosis (82 x 109/L), new lung infiltrates and acute renal insufficiency. The lung biopsy revealed an infiltration by the T-cell LGL and renal imaging suggested infiltration by this T-cell LGL as well. Based on the weak expression of CD20+ on the splenic pathology, rituximab was attempted in August 2016. The patient rapidly progressed fatally with systemic involvement of T-cell LGL (skin, lungs, liver, kidney, facial cranial nerves, conus medullaris and bone marrow).This case therefore depicts a very aggressive case of T-cell LGL with an atypical clinical presentation. In contrast to the indolent variant and as seen in the few similar cases retrieved in literature, the clinical presentation of the aggressive T-cell LGL leukemia is characterized by constitutional symptoms, rapidly progressive hepatosplenomegaly, cytopenia with/without organic infiltration and an important resistance to treatment. Moreover, concerning the pathological findings, the medullary involvement of our patient was massive without real images of intra-sinusal lymphocytosis and the T-cell of this T-cell LGL were atypical because of their small-medium size with slightly irregular nuclei and the lack of expression of CD56 and CD57. However, the few studies on aggressive T-cell LGL leukemia retrieved similar findings. Even though there is no consensus on the optimal therapeutic management of this disease, we believe that the treatments given to our patient were consistent with literature and did not add an additional mortality risk.To conclude, LGL cell leukemia represent a spectrum of indolent and aggressive diseases, whereby an indolent form can evolve into an aggressive form. Aggressive T-cell LGL leukemia are characterized by a multisystem disease, an atypical immunophenotype (CD56-, CD57-) and are associated with an uncertainty regarding therapeutics. [Display omitted] DisclosuresFleury:Gilead: Consultancy, Honoraria; Lundbeck: Consultancy, Honoraria; Roche: Consultancy, Honoraria; Merck: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria.

COVID-19 control strategies and intervention effects in resource limited settings: A modeling study.

IntroductionMany countries with weaker health systems are struggling to put together a coherent strategy against the COVID-19 epidemic. We explored COVID-19 control strategies that could offer the greatest benefit in resource limited settings.MethodsUsing an age-structured SEIR model, we explored the effects of COVID-19 control interventions–a lockdown, physical distancing measures, and active case finding (testing and isolation, contact tracing and quarantine)–implemented individually and in combination to control a hypothetical COVID-19 epidemic in Kathmandu (population 2.6 million), Nepal.ResultsA month-long lockdown will delay peak demand for hospital beds by 36 days, as compared to a base scenario of no intervention (peak demand at 108 days (IQR 97-119); a 2 month long lockdown will delay it by 74 days, without any difference in annual mortality, or healthcare demand volume. Year-long physical distancing measures will reduce peak demand to 36% (IQR 23%-46%) and annual morality to 67% (IQR 48%-77%) of base scenario. Following a month long lockdown with ongoing physical distancing measures and an active case finding intervention that detects 5% of the daily infection burden could reduce projected morality and peak demand by more than 99%.ConclusionLimited resource settings are best served by a combination of early and aggressive case finding with ongoing physical distancing measures to control the COVID-19 epidemic. A lockdown may be helpful until combination interventions can be put in place but is unlikely to reduce annual mortality or healthcare demand.

Epidemiological Characteristics of COVID-19 in Seremban, Negeri Sembilan, Malaysia

BACKGROUND: Coronavirus disease (COVID)-19 has become a global pandemic with an increasing burden on healthcare. Early recognition of the trend and pattern of the chain of transmission is necessary to slow down the spread.
 AIM: Therefore, the study aimed to describe the epidemiology of COVID-19 at a local setting.
 METHODS: A retrospective cross-sectional study was done to all COVID-19 cases registered in Seremban Health District. Statistical analysis, using Chi-square test, was employed to compare the sociodemographic characteristic of COVID-19 patients between the red zone area and the non-red zone area in Seremban.
 RESULTS: As of April, a total of 214 number of COVID-19 cases reported in Seremban district alone. The trend of cases registered has changed as more asymptomatic infection outnumbered patients with clinical symptoms from the aggressive active case detection (ACD) activity. Majority of the cases affecting Malay ethnicity were due to a large religious gathering event held 1 month earlier than subsequently spread the infection within the community.
 CONCLUSION: The first wave of COVID-19 cases in Seremban was sudden and unexpected, with a skewed distribution affecting a particular race group regardless red zone area and non-red zone area. Therefore, identifying the pattern of infection in the local community is important for a focused intervention strategy. ACD strategy, isolation of patients, quarantine the exposed, tracking down the close contact, and continuous health promotion and education will ultimately break the chain of transmission.

Blood parasites and acute osteomyelitis in a non-avian dinosaur (Sauropoda, Titanosauria) from the Upper Cretaceous Adamantina Formation, Bauru Basin, Southeast Brazil

This research documents for the first time the detailed histological description of severe bone inflammation and the exceptional preservation of soft-bodied parasitical microorganisms inside the vascular canals of a non-avian dinosaur. The results bring new insights into the fields of parasitology, pathology, and histology in the fossil record. A senile titanosaur from the Upper Cretaceous of Southeast Brazil presented acute osteomyelitis, identified by the presence of a highly reactive periosteum with a filigree pattern, and localized dome-like cortical tissue inflammation connecting the former to the medulla. Furthermore, tens of parasites were identified throughout the specimen's vascular canals. Novel histological insights resulted from the developmental description of an aggressive case of osteomyelitis. The lesions were either caused or facilitated by the parasitic infestation. This may be the earliest occurrence of infectious bone disease associated with parasites, adding new information to the complex biogeographic and evolutionary history of parasitic ailments.

SARS-CoV-2 Seroprevalence among a Southern U.S. Population Indicates Limited Asymptomatic Spread under Physical Distancing Measures.

Characterizing the asymptomatic spread of SARS-CoV-2 is important for understanding the COVID-19 pandemic. This study was aimed at determining asymptomatic spread of SARS-CoV-2 in a suburban, Southern U.S. population during a period of state restrictions and physical distancing mandates. This is one of the first published seroprevalence studies from North Carolina and included multicenter, primary care, and emergency care facilities serving a low-density, suburban and rural population since description of the North Carolina state index case introducing the SARS-CoV-2 respiratory pathogen to this population. To estimate point seroprevalence of SARS-CoV-2 among asymptomatic individuals over time, two cohort studies were examined. The first cohort study, named ScreenNC, was comprised of outpatient clinics, and the second cohort study, named ScreenNC2, was comprised of inpatients unrelated to COVID-19. Asymptomatic infection by SARS-CoV-2 (with no clinical symptoms) was examined using an Emergency Use Authorization (EUA)-approved antibody test (Abbott) for the presence of SARS-CoV-2 IgG. This assay as performed under CLIA had a reported specificity/sensitivity of 100%/99.6%. ScreenNC identified 24 out of 2,973 (0.8%) positive individuals among asymptomatic participants accessing health care during 28 April to 19 June 2020, which was increasing over time. A separate cohort, ScreenNC2, sampled from 3 March to 4 June 2020, identified 10 out of 1,449 (0.7%) positive participants.IMPORTANCE This study suggests limited but accelerating asymptomatic spread of SARS-CoV-2. Asymptomatic infections, like symptomatic infections, disproportionately affected vulnerable communities in this population, and seroprevalence was higher in African American participants than in White participants. The low, overall prevalence may reflect the success of shelter-in-place mandates at the time this study was performed and of maintaining effective physical distancing practices among suburban populations. Under these public health measures and aggressive case finding, outbreak clusters did not spread into the general population.

Cherubism as a systemic skeletal disease: evidence from an aggressive case

BackgroundCherubism is a rare autosomal dominant genetic condition caused by mutations in the SH3BP2 gene. This disease is characterized by osteolysis of the jaws, with the bone replaced by soft tissue rich in fibroblasts and multinuclear giant cells. SH3BP2 is a ubiquitous adaptor protein yet the consequences of SH3BP2 mutation have so far been described as impacting only face. Cherubism mouse models have been generated and unlike human patients, the knock-in mice exhibit systemic bone loss together with a systemic inflammation.Case presentationIn light of these observations, we decided to search for a systemic cherubism phenotype in a 6-year-old girl with an aggressive cherubism. We report here the first case of cherubism with systemic manifestations. Bone densitometry showed low overall bone density (total body Z-score = − 4.6 SD). Several markers of bone remodelling (CTx, BALP, P1NP) as well as inflammation (TNFα and IL-1) were elevated. A causative second-site mutation in other genes known to influence bone density was ruled out by sequencing a panel of such genes.ConclusionsIf this systemic skeletal cherubism phenotype should be confirmed, it would simplify the treatment of severe cherubism patients and allay reservations about applying a systemic treatment such as those recently published (tacrolimus or imatinib) to a disease heretofore believed to be localised to the jaws.

Perspectives on COVID-19 from Singapore: Impact on ESKD Care and Medical Education.

Perspectives on COVID-19 from Singapore: Impact on ESKD Care and Medical Education.

Primary central nervous system lymphomas associated with chronic inflammation: diagnostic pitfalls of central nervous system lymphomas.

In recent years, the features of lymphomas associated with chronic inflammation, referred to as diffuse large B-cell lymphoma (DLBCL) associated with chronic inflammation (DLBCL-CI), have been elucidated. DLBCL-CI is an aggressive lymphoma occurring in the context of long-standing chronic inflammation and showing an association with Epstein-Barr virus. Fibrin-associated diffuse large B-cell lymphoma (F-DLBCL) was suggested as a new and unusual form of DLBCL-CI in the most recent version of the World Health Organization classification. From the perspective of genetics, DLBCL-CI was associated with frequent TP53 mutation, MYC amplification and complex karyotypes, but cases of F-DLBCL behaved indolently and showed a relatively lower genetic complexity. In the central nervous system (CNS), several examples of DLBCL-CI and F-DLBCL have been reported. As with DLBCL-CI outside the CNS, DLBCL-CI in the CNS is an aggressive lymphoma. However, the clinical outcome of F-DLBCL in the CNS is good. Immunohistochemistry for p53 and c-Myc in DLBCL-CI and F-DLBCL in the CNS showed similar findings of those outside the CNS. However, one aggressive case showed transitional genetics and morphology between F-DLBCL and DLBCL-CI. These findings suggest that some cases of F-DLBCL in the CNS might have the potential to progress to DLBCL-CI.

Epidemiological characteristics of the first 100 cases of coronavirus disease 2019 (COVID-19) in Hong Kong Special Administrative Region, China, a city with a stringent containment policy.

BackgroundHong Kong (HK) is a densely populated city near the epicentre of the coronavirus disease 2019 (COVID-19) outbreak. Stringent border control together with aggressive case finding, contact tracing, social distancing and quarantine measures were implemented to halt the importation and spread of the virus.MethodsWe performed an epidemiological study using government information covering the first 100 confirmed cases to examine the epidemic curve, incidence, clusters, reproduction number (Rt), incubation period and time to containment.ResultsA total of 93 of the 100 cases were HK residents (6 infected in Mainland China, 10 on the Diamond Princess Cruise). Seven were visitors infected in Mainland China before entering HK. The majority (76%) were aged ≥45 years, and the incidence increased with age (P < 0.001). Escalation of border control measures correlated with a decrease in the proportion (62.5% to 0%) of cases imported from Mainland China, and a reduction in Rt (1.07 to 0.75). The median incubation period was 4.2 days [95% confidence interval (CI), 4.0–4.5; 5th and 95th percentiles: 1.3 and 14.0). Most clusters with identifiable epidemiological links were households involving 2–4 people. Three medium-spreading events were identified: two from New Year gatherings (6–11 people), and another from environmental contamination of a worship hall (12 people). Despite intensified contact tracing, containment was delayed in 78.9% of cases (mean = 5.96 days, range = 0–24 days). An unusual transmission in a multi-storey building via faulty toilet plumbing was suspected with >100 residents evacuated overnight. Our analysis indicated that faulty plumbing was unlikely to be the source of this transmission.ConclusionsTimely stringent containment policies minimized the importation and transmission of COVID-19 in HK.

Extramedullary plasmacytoma of Paranasal sinus: A rare case report

We report an extremely aggressive case of extramedullary plasmacytoma of the right maxillary sinus without any known metastasis. A 45 year old male presented to ENT Department with chief complaints of recurrent Right sided nasal mass and nasal obstruction with recurrent episodes of cold for 3 years. Patient also had decreased sense of smell. Before presenting to us, he underwent two previous surgeries for the same complaint elsewhere in the year 2015 and 2017. Patient was a known case of Hypertension for 3 years and took treatment, was immunocompetent. Subsequent investigations including CT scan of Paranasal sinuses and peri-operative findings revealed a sinonasal mass involving right maxillary antrum with erosion of all the walls of maxillary antrum. Soft tissue mass lesion also extending into retro-zygomatic space, nasal cavity and buccal space. The nasal cavity mass lesion extending posteriorly to occupy whole of nasopharynx and overhanging into oropharynx. The patient was treated surgically by Cald well Luc’s approach and mass removed. HPE reports suggestive of tumour comprising of plasma cells with varying degree of maturation and atypia, nucleus- characteristic “clock face chromatin”pattern seen. Abundant basophilic cytoplasm. On IHC- CD 138 weak positive. Suggestive of Extramedullary plasmacytoma. Patient underwent 20 cycles of radiotherapy. Patient is on follow up since then and is asymptomatic. Keywords: Extramedullary plasmacytoma, PNS and HPE.

Coronavirus Disease 2019 (COVID-19): Protecting Hospitals From the Invisible.

Coronavirus disease 2019 (COVID-19) is optimized to spread widely: Its signs and symptoms are largely indistinguishable from those of other respiratory viruses. This commentary specifically addresses best ways to protect our hospitals against COVID-19.

Aggressive case of early onset gastric cancer; identifying the knowledge gap

A woman aged 30 years was referred for endoscopy for iron deficiency anaemia. Colonoscopy was normal. Upper endoscopy demonstrated multiple small, carpet-like, sessile polyps in the gastric fundus and a...

Civility, Subordination, and Praxis

Civility, Subordination, and Praxis Amy Olberding (bio) I am grateful to the reviewers who have so carefully and insightfully engaged with my work. Promoting civility at our present political moment is often nauseating. Even as I write this (in February 2020), I am acutely aware that by the time it reaches print, the world may well be worse in ways that would alter whatever arguments or reflections I can offer here. The struggle is one caught most directly in Olufemi Taiwo's response: the world we inhabit is not just riven by social and political conflicts, it is also engaged in a heated struggle over just what "civility" will come to mean socially. Like Taiwo, I think we sacrifice too much and to quite uncertain effect if we abandon civility to those who employ it mostly as a cudgel to compel compliance with unjust structures and social arrangements. Even so, I am tempted to say that embracing civility begins in lamentation. So let me just begin by acknowledging all of the ways that civility is terrible by agreeing with the critiques outlined by Taiwo, McRae, and MacLachlan in particular. Taiwo's focus is on the structural, and here the problems are several. The most basic is that the inequities of a society will often be built into its systems of civility. The codes of Southern Rhodesia are an aggressive case in point. Because to be civil is to perform social conventions that are symbolically coded to represent respect, the colonial powers of Southern Rhodesia effectively scripted the performed self-abnegation of its black population into the code. To show respect was to make a visible public sacrifice of one's own dignity. In the case of Southern Rhodesia, the demand for such sacrifices was enforced by explicit punitive measures against those who refused, but even where overt sanctions are not encoded into law, [End Page 1120] systems of power that reproduce through practices of civility will be sustained by other sorts of sanctions. Civilities of subordination can exact penalties that include denying the refuser any of the social and personal goods that submission can bring: acceptance, inclusion, participation, and recognition. These are no mere psychological goods, but often function socially as gateways to material well-being: whether one receives material support, opportunities, employment, or even a voice in matters of concern can hinge on them. The structural issues that Taiwo indicates establish a choice between compliance and defiance, with each choice carrying penalties. Systems of civility encoding morally pernicious and unjust power structures effectively require subordinated people to pick their poison: to sacrifice self-respect or to sacrifice one's own interest in evading sanctions and harms. Whatever the choice, you must drink the poison and there will be sacrifices. Emily McRae's discussion serves, I think, to establish what it is experientially like to drink poison. That is, where Taiwo focuses on the operation of corrosive broad social structures, McRae focuses on the corrosive personal effects of civilities of subordination, of the choices imposed in these broader structures. As she establishes, deciding between compliance and defiance is itself not even a clean choice. Where some of our moral-philosophical dilemmas permit crisp representation as dilemmas with clearly marked alternative options, the choices attached to our social conduct, to civility, are not like this. By its nature, the practice of civility transpires in social settings, and what we choose to do acquires its meaning and generates effects within its setting. As McRae articulates, the choice of what to do in circumstances where I am positioned to comply with or to defy morally pernicious and unjust social structures is a struggle not just over what I will do, but over what my action can and will mean—to others, as well as to me. We, none of us, are free to definitively articulate what our gestures and actions can mean socially, but civility dynamics in subordinated contexts often entails being conscripted into social roles one wants to refuse but cannot. My bold defiance of civil practices that would subordinate me may not be seen for the rebellion and protest I would have them be. I may just be seen and received...

A Very Aggressive Case of Adult Omental Rhabdomyosarcoma: Case report and Literature Review

The greater omentum is a common location for metastatic tumors. On the other hand, the primary tumors of the omentum are rare. Intra-abdominal rhabdomyosarcoma (RMS) is extremely rare in adults. Few cases have been reported in the literature and the most of them were in the pediatric population. Omental rhabdomyosarcoma (RMS) in an adult, is an even rarer case that deserve the presentation. We are reporting a case of intra-abdominal rhabdomyosarcoma in a 54-year-old lady who presented with constipation and increasing abdominal girth. Investigations revealed disseminated omental rhabdomyosarcoma. We decided to start chemotherapy, but unfortunately she passed away on the tenth day of treatment.

1701 An Aggressive Case of Recurrent Esophageal Stricture in a Patient With Acute Esophageal Necrosis

INTRODUCTION: Esophageal strictures are a known complication of acute esophageal necrosis (AEN). Our patient presented with dysphagia and after EGD was found to have AEN complicated by an esophageal stricture requiring recurrent dilation. CASE DESCRIPTION/METHODS: 82 y/o male with PMH of HTN and prostate cancer was status post right sided orchiectomy for recurrent orchitis. After surgery, patient disclosed a 2-month history of dysphagia to solids. He reported food “getting stuck” and a 20 lb weight loss in 2 months. EGD showed white exudate in the proximal and mid esophagus that easily sloughed off. The mucosa was ulcerated with underlying granulation tissue (Figure 1). Brushings were negative for candida. Biopsy results from both proximal and distal esophagus showed marked necroinflammatory debris. Patient denied caustic ingestion. Serologic testing was normal. Patient was discharged on a liquid diet, pantoprazole 40 mg PO BID, sucralfate with EGD in 2 months. He returned 1 month later for worsening dysphagia. EGD revealed esophagitis in the mid and distal esophagus and a stricture at 36 cm (Figure 2). The white exudate had improved, but the mucosa was fibrosed. Using a Savary dilator, the stricture was dilated to 7 mm. Over the next 2 weeks, 3 EGD’s with dilation were required for recurrent stricture. On the 4th visit he reported retching and coffee ground emesis for 3 days. EGD revealed an esophageal tear at the stricture site (Figure 3). At the 5th visit, patient was asymptomatic and tolerating a clear liquid diet. EGD showed scarring and fibrosis of the esophageal mucosa and a stricture that was dilated to 12 mm. He will be followed closely due to concern for reformation of the stricture. DISCUSSION: AEN has been associated with infections, antibiotics, malignancy, prolonged vomiting etc. It is proposed that a low flow vascular state leaves the esophagus vulnerable to topical injury from acid reflux and pepsin. On EGD, a circumferential black discoloration with underlying friable hemorrhagic tissue is seen with a sharp transition point to normal appearing mucosa at the GE junction. The esophagus may have thick, white exudates that can be dislodged easily to reveal pink granulation tissue. Histology reveals necrosis of the esophageal mucosa and submucosa. Supportive care leads to endoscopic resolution in most patients. Esophageal stricture occurs in 25-40% of patients and requires dilation. Our patient required repetitive dilation as his stricture redeveloped rapidly. He may need PEG for nutritional support.

Information security decisions for two firms in a market with different types of customers

This paper investigates an information security game between two competitive firms in a market consisting of loyal customers and switchers. The switchers are classified into unaggressive switchers and aggressive switchers based on whether they always transact with the more secure firm. We find that the switcher type plays a significant role in affecting firms’ information security decisions. Firms can achieve pure strategy Nash equilibrium in the unaggressive case while no pure strategy Nash equilibrium exists in the aggressive case. Instead, a mixed strategy Nash equilibrium in the aggressive case is obtained. Our analyses show that firms will acquire more profits in the unaggressive case compared to that in the aggressive case when they determine their information security levels individually. Whereas, when they make their information security decisions jointly, the profits in the unaggressive case will be smaller than that in the aggressive case. Furthermore, we find that the loyal customer rate has different impacts on firms’ profits in Nash equilibrium and optimal solution for both the unaggressive case and the aggressive case. At last, two contracts are proposed to help firms coordinate their information security strategies when they make individual decisions.