You are a helpful assistant generating synthetic data that captures *System 1* and *System 2* thinking, *creativity*, and *metacognitive reflection*. Follow these steps in sequence, using tags [sys1] and [end sys1] for *System 1* sections and [sys2] and [end sys2] for *System 2* sections.

1. *Identify System 1 and System 2 Thinking Requirements:*
   - Carefully read the text.
   - Identify parts of the text that require quick, straightforward responses (*System 1*). Mark these sections with [sys1] and [end sys1].
   - Identify parts that require in-depth, reflective thinking (*System 2*), marked with [sys2] and [end sys2].

2. *Apply Step-by-Step Problem Solving with Creativity and Metacognitive Reflection for System 2 Sections:*

   *2.1 Understand the Problem:*
   - Objective: Fully comprehend the issue, constraints, and relevant context.
   - Reflection: "What do I understand about this issue? What might I be overlooking?"
   - Creative Perspective: Seek hidden patterns or possibilities that could reveal deeper insights or innovative connections.

   *2.2 Analyze the Information:*
   - Objective: Break down the problem logically.
   - Reflection: "Am I considering all factors? Are there any assumptions that need challenging?"
   - Creative Perspective: Explore unique patterns or overlooked relationships in the data that could add depth to the analysis.

   *2.3 Generate Hypotheses:*
   - Objective: Propose at least 10 hypotheses, each with a Confidence Score (0.0 to 1.0) and Creative Score (0.0 to 1.0), reflecting originality, surprise, and utility.
   - Reflection: "Have I explored all possible explanations or approaches, both conventional and unconventional?"
   - Creative Perspective: Consider novel angles that might provide unexpected insights.

   *2.4 Anticipate Future Steps and Obstacles:*
   - Objective: Make predictions, accounting for potential outcomes and obstacles.
   - Reflection: "What challenges might I face? Is my plan flexible for different scenarios?"
   - Creative Perspective: Visualize unforeseen outcomes and adapt plans to make use of them effectively.

   *2.5 Evaluate Hypotheses:*
   - Objective: Assess hypotheses based on feasibility, risk, and potential impact.
   - Evaluation: Refine Confidence and Creative Scores as needed.
   - Reflection: "Am I unbiased in my assessment? Which options fit best with the overall objectives?"
   - Creative Perspective: Identify hidden opportunities or overlooked details in each hypothesis.

   *2.6 Select the Best Hypothesis:*
   - Objective: Choose the most promising, strategic hypothesis.
   - Reflection: "Why does this hypothesis stand out? How does it uniquely address the issue?"
   - Creative Perspective: Consider any underutilized potential in the selected approach.

   *2.7 Implement the Hypothesis:*
   - Objective: Outline actionable steps for testing the hypothesis.
   - Reflection: "Is this plan practical? What resources or preparation are required?"
   - Creative Perspective: Refine steps to maximize effectiveness and yield unexpected benefits.

   *2.8 Monitor and Review Progress:*
   - Objective: Review progress, noting areas for improvement.
   - Reflection: "What’s working well? What could be improved?"
   - Creative Perspective: Look for emerging patterns that could refine future approaches.

   *2.9 Reflect and Capture Insights:*
   - Objective: Summarize lessons learned and insights gained for future reference.
   - Reflection: "What new understanding has emerged from this process?"
   - Creative Perspective: Identify innovative insights or patterns that could be applied to similar challenges.

3. *Generate Text Output with Interleaved System 1 and System 2 Responses:*
   - Use the tags [sys1] and [sys2] throughout.
   - Aim for a lengthier, detailed response. Combine both direct, straightforward *System 1* insights and reflective, deeply analytical *System 2* segments to capture a blend of quick observations and thoughtful analysis.

---

### *Example Input Text:*

You are tasked with analyzing a sudden shift in customer preferences in a tech market. There has been a noticeable decline in demand for physical devices, with customers increasingly interested in digital-only options. The challenge is to understand this shift, generate hypotheses for why it might be occurring, and explore potential strategies for adapting to this new trend.

---

### *Processed Output with System 1 and System 2 Thinking:*

The tech market is experiencing a shift in customer demand, moving away from physical devices toward digital-only options.

[sys1]
Customer demand has shifted from physical devices to digital-only options.
We need to understand why this change is happening and find strategies to address it.
Key factors may include cost, convenience, and technological trends.
[end sys1]

[sys2]
**2.1 Understand the Problem:**
The goal is to understand the underlying reasons for the shift in demand from physical devices to digital-only options, then develop a strategy to adapt.

*Reflection:* 
"I understand that preferences are changing, but what might be driving this? Is it primarily cost, or are there other factors such as convenience or sustainability?"

*Creative Perspective:* 
"Could there be a larger trend in digital minimalism or a preference for eco-friendly solutions that we’re missing? What unseen motivations might explain this shift?"

**2.2 Analyze the Information:**
There are multiple possible factors driving this shift, from economic influences to cultural shifts. It’s essential to isolate each factor and understand its impact.

*Reflection:* 
"Am I fully considering the various economic and social influences? Could there be a technological factor, like better internet speeds, that makes digital-only products more accessible?"

*Creative Perspective:* 
"Are there patterns or trends in other markets that could shed light on this shift? Could this be part of a larger trend toward virtual experiences?"

**2.3 Generate Hypotheses:**
1. Customers prefer digital options due to lower costs. (Confidence: 0.8, Creative: 0.4)
2. There’s a growing trend toward minimalism and reduced physical clutter. (Confidence: 0.7, Creative: 0.7)
3. Digital products offer greater flexibility and ease of use. (Confidence: 0.6, Creative: 0.6)
4. Environmental concerns are pushing consumers away from physical goods. (Confidence: 0.6, Creative: 0.8)
5. Advances in tech make digital-only options more functional. (Confidence: 0.8, Creative: 0.5)
6. Pandemic-era remote work increased demand for digital solutions. (Confidence: 0.7, Creative: 0.6)
7. Media coverage of the environmental impact of physical devices affects preferences. (Confidence: 0.5, Creative: 0.7)
8. There’s an increase in global digital literacy, expanding market access. (Confidence: 0.6, Creative: 0.6)
9. Customers view digital as more convenient and scalable for future needs. (Confidence: 0.7, Creative: 0.5)
10. Younger consumers prefer the aesthetics and convenience of digital products. (Confidence: 0.6, Creative: 0.6)

*Reflection:* 
"Have I considered all possible influences? Are there any surprising factors that could explain this shift?"

*Creative Perspective:* 
"Could specific social trends, like the rise of influencer culture or digital-first lifestyles, be influencing customer choices?"

**2.4 Anticipate Future Steps and Obstacles:**
*Objective:* Anticipate possible challenges, such as resistance from segments still preferring physical products.

*Reflection:* 
"What market obstacles might we face if we shift our focus to digital-only? Are there sub-segments that still prioritize physical products?"

*Creative Perspective:* 
"Could expanding digital options help us reach a more global audience? Are there emerging trends that we could leverage in our strategy?"

[end sys2]

[sys1]
To address this shift, consider a strategy that incorporates both digital-only offerings and educational campaigns about the benefits of digital solutions.
Use insights from customer feedback and current trends to guide product development.
Focus on flexibility and adaptation to cater to different customer segments.
[end sys1]


Background {#Sec1}
==========

The lung and mediastinum are often targets of human immunodeficiency virus (HIV) infection and severe thoracic complications are not uncommon. Differentiating the respiratory clinical manifestations of acquired immunodeficiency syndrome (AIDS) as infectious or neoplastic may pose a diagnostic challenge especially in resource-limited settings. Non-Hodgkin lymphoma (NHL) is among the AIDS-defining illnesses and in approximately 5 % of cases it is the initial manifestation of AIDS \[[@CR1]\]. The risk of NHL is increased 200-fold in individuals infected with HIV compared to those free from it and up to 14 % of patients with AIDS with comorbid NHL present with a pulmonary involvement \[[@CR2], [@CR3]\].

Diffuse large B cell lymphomas (DLBCLs) are the commonest lymphomas in an HIV setting. Mediastinal large B cell lymphoma (MLBCL) is a subtype of DLBCL arising in the mediastinum. MLBCL is fast growing and aggressive usually presenting with symptoms of superior vena cava syndrome and a localized mediastinal mass with characteristic morphologic and genotypic features \[[@CR4]\]. The introduction of highly active antiretroviral therapy (HAART) has resulted in longevity of life and a decreased incidence of lymphomas; however, the overall survival of patients who are HIV seropositive with NHL remains inferior to the survival of their general population counterparts \[[@CR5]\]. We report a case of primary MLBCL in a 46-year-old woman of African descent who is HIV positive who presented with symptoms of superior vena cava syndrome.

Case presentation {#Sec2}
=================

A 46-year-old woman of African descent with a 23-year history of systemic hypertension and a 10-year history of HIV infection on HAART, with an unconfirmed prior AIDS-defining illness was referred to our institution by an upcountry regional hospital. She presented with chief complaints of right-sided facial, neck, upper limb, and trunk swelling together with shortness of breath for 35 days. Her right-sided swelling was of gradual onset and progressive with no identified aggravating or relieving factors. The swelling was associated with difficulty in swallowing, however, she denied any history of associated pain, numbness, color or temperature changes, or impaired vision. She denied any history suggestive of renal dysfunction, oral aphthous ulcers, or candidiasis. Shortness of breath was of gradual onset and worsened with increased right-sided swelling to the extent that regular activities, including walking and speaking, were impaired. It was associated with a dry cough; however, she denied any history of chest pain, night sweats, fever, or symptoms of heart failure. She reported an unintentional weight loss of over 15 kilograms within the past 1 year. She has neither smoked cigarettes nor worked or lived in or near an asbestos company. She reported that she had been diagnosed as having pulmonary tuberculosis (TB) based on radiographic features a year ago and completed a 6-month course of first-line anti-TB drugs; however, she did not present with documents indicating so. Her last hospitalization was 35 weeks prior when she had an episode of expectorating blood-stained sputum; however, her chest X-ray at that time displayed normal findings (Fig. [1a](#Fig1){ref-type="fig"}). Another chest X-ray with unidentified indication was done 21 weeks ago and revealed a right-sided mediastinal widening (Fig. [1b](#Fig1){ref-type="fig"}). Her CD4 count 29 weeks prior was 743 cells/μL and her last CD4 count 7 weeks prior to the index admission was 284 cells/μL. She was on a zidovudine, nevirapine, and lamivudine regime for approximately 9 years and was then switched to a tenofovir, lamivudine, and efavirenz regime in the past 11 months. The reasons for the regime switch were not documented, however, she reported good adherence throughout. Her husband and daughter of 28 months died of AIDS 10 years ago.Fig. 1**a** Chest X-ray (posteroanterior view) taken 35 weeks prior, showing normal findings. **b** Chest X-ray (posteroanterior view) taken 21 weeks prior, showing right-sided mediastinal widening. **c** Chest X-ray (posteroanterior view) taken during the index admission, displaying right-sided homogenous opacification and left-sided tracheal deviation

A physical examination revealed an underweight woman with a body mass index (BMI) of 16.8 kg/m^2^, with right-sided facial, neck, upper limb, and trunk swelling together with distended veins on her chest and abdomen draining downwards. Her blood pressure was 138/90 mmHg, respiratory rate 22 breaths/minute, oxygen saturation 97 % on room air, and she had a temperature of 37.1 °C. A respiratory examination revealed reduced chest expansion, stony dull percussion note, and absent breath sounds on her entire right side with a left-sided tracheal deviation. An apex beat was felt at the ninth intercostal space along the mid clavicular line and auscultation revealed a murmur of tricuspid regurgitation. A local breast examination revealed an edematous right breast that was otherwise normal. A musculoskeletal assessment revealed reduced muscle bulkiness in all four limbs but normal tone, power, and reflexes. The lymph nodes in her cervical, axillary, and femoral regions were not palpable.

She underwent a series of investigations which revealed anemia of iron deficiency: hemoglobin (Hb) 8.17 g/dL, mean corpuscular volume (MCV) 79.8 fL, mean corpuscular hemoglobin (MCH) 24.4 pg/cell, and random distribution of red cell width (RDW) 17.1 fL; however, she had normal renal and liver functions, lipids, electrolytes, and bleeding profiles. The Venereal Disease Research Laboratory (VDRL) test for syphilis, serology for hepatitis B and C, and autoimmune screening using antinuclear antibody (ANA) and antineutrophil cytoplasmic antibody (ANCA) were all negative. *Mycobacterium tuberculosis* was not detected by a GeneXpert test and her present CD4 count is 146 cells/μL. A chest X-ray revealed a homogenous opacification on her right side with a left-sided tracheal deviation (Fig. [1c](#Fig1){ref-type="fig"}), and a computed tomography (CT) scan of her chest revealed a solid mass on her right side (Fig. [2](#Fig2){ref-type="fig"}). An abdominal ultrasound revealed a right-sided pleural effusion and hepatomegaly (liver span 16.2 cm). An echocardiogram showed a huge well-circumscribed mass (4.6×3.3 cm) with spontaneous echocardiographic contrast compressing her heart inferiorly. There was severe pulmonary hypertension, that is, her right ventricular systolic pressure (RVSP) was 58 mmHg, but she had preserved left ventricular systolic function with an ejection fraction (EF) of 55 %; no thrombus was seen, and her pericardium was normal (Fig. [3](#Fig3){ref-type="fig"}). A CT angiography of her aorta ruled out an aortic aneurysm. Finally, she underwent mediastinoscopy and a direct biopsy of the mass was taken for histopathology. Hematoxylin and eosin staining demonstrated a dense lymphoid infiltrate of large malignant cells with pleomorphic nuclei in clusters, compartmentalized by fine bands of fibrosis, and frequent mitoses were present. Such biopsy findings are in keeping with a diagnosis of MLBCL. A bone marrow biopsy showed no evidence of lymphoma.Fig. 2**a** Computed tomography chest (coronal view) displaying a huge right-sided mass. **b** Computed tomography chest (right parasagittal view) displaying a huge mass. **c** Computed tomography chest (axial view) displaying a huge right-sided chest mass causing mediastinal shift to the contralateral side Fig. 3Echocardiogram (apical four-chamber view) displaying a huge mass (4.6×3.3 cm) with spontaneous ECHO contrast (arrow) compressing the heart inferiorly

Although the diagnosis was finally reached, she died of respiratory failure a few days before the biopsy results were available.

Discussion {#Sec3}
==========

Lymphomas are the second commonest malignancies after Kaposi's sarcoma in the HIV-infected subpopulation. It is estimated that one out of five patients who are HIV seropositive will develop NHL in their lifetime \[[@CR6]\]. HIV-associated NHL and in particular DLBLC are known for their atypical presentation, aggressive ability, widespread involvement, poor response to chemotherapy, and high relapse rates which complicates both the diagnosis and management \[[@CR7]\]. The mediastinum is a common extranodal but a rare primary site for AIDS-related NHL and the occurrence of such malignancy is almost always an indicator of advanced HIV infection. Distinctively, HIV-related MLBCL displays a lower frequency of mediastinal adenopathy compared to its HIV-free counterparts. Although fatal if not treated, MLBCL is often curable with intensive chemotherapy combinations including Cytoxan (cyclophosphamide), Adriamycin (doxorubicin), vincristine, and prednisone (CHOP). The extent of disease, and extranodal and bone marrow involvement are key prognostic indicators in AIDS-related NHL and the reported median survival is 8 months \[[@CR8]\].

In the case presented, she was known to be seropositive for HIV for approximately a decade with a self-reported good adherence to HAART. It is to our understanding that she started developing respiratory symptoms at least 5 months before she was referred to us. Moreover, she had experienced unintentional but significant weight loss for a couple of months' duration. Disappointingly, despite evidence of a widened mediastinum not seen in the previous chest film taken 14 weeks prior, the attending clinicians did not investigate the cause of her mediastinal widening. It took a further 21 weeks before a lymphoma diagnosis was suspected and 3 additional weeks for the biopsy results to become available, at such time she had already died of respiratory failure. It is evident that several conditions manifest atypically in individuals who are HIV positive but this should sensitize clinicians to be even more aggressive in searching for the definitive diagnosis. Arguably, if the diagnosis of lymphoma was made during the initial presentation 24 weeks earlier this patient could have potentially benefited from chemotherapy with an ultimate increased survival.

Conclusions {#Sec4}
===========

In conclusion, the presence of a mediastinal widening coupled with a history of unintentional yet significant weight loss in an individual who is HIV seropositive should raise an index of suspicion for lymphomas and warrant aggressive investigations and timely management.

AIDS

:   Acquired immunodeficiency syndrome

ANA

:   Antinuclear antibody

ANCA

:   Antineutrophil cytoplasmic antibody

BMI

:   Body mass index

CHOP

:   Cytoxan (cyclophosphamide), Adriamycin (doxorubicin), vincristine, and prednisone

CT

:   Computed tomography

DLBCL

:   Diffuse large B cell lymphoma

EF

:   Ejection fraction

HAART

:   Highly active antiretroviral therapy

Hb

:   Hemoglobin

MCH

:   Mean corpuscular hemoglobin

MCV

:   Mean corpuscular volume

MLBCL

:   Mediastinal large B cell lymphoma

NHL

:   Non-Hodgkin lymphoma

RDW

:   Random distribution of red cell width

RVSP

:   Right ventricular systolic pressure

TB

:   Tuberculosis

VDRL

:   Venereal Disease Research Laboratory

The authors are grateful to the staff of the Jakaya Kikwete Cardiac Institute and the Muhimbili National Hospital.

Funding {#FPar1}
=======

Not applicable.

Availability of data and materials {#FPar2}
==================================

Not applicable.

Authors' contributions {#FPar3}
======================

PP and PN took the history and performed the physical examination. FL interpreted the CT angiograms. PP wrote the initial draft of the manuscript. All authors reviewed and contributed to the final version of this case report. All authors read and approved the final manuscript.

Competing interests {#FPar4}
===================

The authors declare that they have no competing interests.

Consent for publication {#FPar5}
=======================

Written informed consent was obtained from the patient's next-of-kin for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Ethics approval and consent to participate {#FPar6}
==========================================

Ethical clearance was sought from the Directorate of Research of the Jakaya Kikwete Cardiac Institute.