Fibrosing mediastinitis: a rare complication of histoplasmosis

Demographic, clinical, and paraclinical features of patients operated with the diagnosis of acute descending necrotizing mediastinitis: a retrospective study in Southern Iran

INTRODUCTION

Descending necrotizing mediastinitis (DNM) is a type of acute mediastinitis that is rarely reported but is regarded as a fatal disease despite improvements in technological methods and antibiotic therapies. We aimed to determine the demographic, clinical, and paraclinical features of patients diagnosed with acute DNM.

METHODS

In this retrospective study, patients' hospital records with a diagnosis of DNM admitted to the Namazi hospital in southern Iran during 18 years (2002-2019) were reviewed. Demographic and clinical features were recorded and subsequently analyzed via SPSS 22.

RESULTS

Out of 67 mediastinitis patients, 25 (37.3%) were diagnosed as DNM with an average age of 37.2 ± 16.7 years, and 68% were male. Regarding etiology, 52.0% were due to neck infection. Based on the technique of surgery, 52% of the patients underwent the combined method, which was mostly among type I and IIA DNM, while thoracotomy was mostly performed on type IIB DNM (P = 0.08). Based on the incision, type IIA and IIB had the highest frequency of thoracotomy and cervicothoracic incisions (P = 0.02 and 0.002). Puss discharge was significantly lower in type I DNM (P = 0.01). Based on the presenting symptoms of our patients, the majority (72.0%) had a chief complaint of neck pain, followed by chills and fever (48%). There were no reports of mortality during our short-term follow-up.

CONCLUSION

We report one of the largest retrospective studies of DNM patients in our referral center, with a high prevalence of the disease among younger populations, especially under 40 years. The method of treatment should be chosen based on the extent of infection and can be limited to neck exploration in upper mediastinal infections, though thoracic or combined approach in more broad infections.

Fibrosing Mediastinitis Presenting With Superior Vena Cava Syndrome

Fibrosing mediastinitis (FM) is an uncommon diagnosis that involves the proliferation of extensive, dense fibrous tissue in the mediastinum. FM accounts for less than 1% of people with prior infection by Histoplasma capsulatum that develop hypersensitivity immune responses to antigens released during the initial exposure. Other causes include tuberculosis, blastomycosis, sarcoidosis, radiation, and idiopathic.  We describe FM presenting with superior vena cava (SVC) syndrome. A 66-year-old Caucasian male presented with a one-week history of progressively worsening facial swelling associated with dysphonia, bilateral ptosis, dyspnea on exertion, and unintentional weight loss of 30 pounds within the past three months. He had a 40-pack-year smoking history and a past medical history of essential hypertension, peripheral vascular disease, and bilateral internal carotid artery stenosis. The CT chest demonstrated non-specific soft tissue extending throughout the mediastinum and towards the right hilar region, complicated by severe attenuation of the superior vena cava and a 2.4 cm × 1.6 cm necrotic lymph node. The mediastinum had hyperemic and desmoplastic changes heavily encased in venous collaterals. L4 lymph node pathological evaluation demonstrated sinus histiocytosis and reactive lymphoid hyperplasia without signs of malignancy or atypia. The patient was treated with corticosteroid and diuretic therapy to achieve intermittent symptomatic relief, but continued to decline clinically, ultimately leading to his demise. The diagnosis of FM is best obtained through CT chest with intravenous contrast to demonstrate abnormal mediastinal tissue and possible structural compromise. A biopsy of the mediastinal tissue may also help rule out malignancy. Only a few case reports have demonstrated mixed symptomatic and radiologic responses to anti-inflammatory and/or antifungal treatment. Even non-surgical and surgical interventions have shown inconsistent efficacy, with frequent restenosis warranting re-exploration.

Endemic pulmonary fungal diseases in immunocompetent patients: an emphasis on thoracic imaging

INTRODUCTION

Systemic endemic mycoses are prevalent in specific geographical areas of the world and are responsible for high rates of morbidity and mortality in these populations, and in immigrants and travelers returning from endemic regions. The most common fungal infections that can affect the lungs of immunocompetent patients include histoplasmosis, coccidioidomycosis, paracoccidioidomycosis, blastomycosis, sporotrichosis, aspergillosis, and cryptococcosis. Diagnosis and management of these diseases remain challenging, especially in non-endemic areas due to the lack of experience. Therefore, recognition of the various radiologic manifestations of pulmonary fungal infections associated with patients' clinical and epidemiologic history is imperative for narrowing the differential diagnosis. Areas covered: This review discusses the clinical and radiological findings of the main endemic fungal diseases affecting the lungs in immunocompetent patients. Specific topics discussed are their etiology, epidemiology, pathogenesis, clinical manifestations, methods of diagnosis, pathology and main imaging findings, especially in computed tomography. Expert commentary: Imaging plays an important role in the diagnosis and management of pulmonary fungal infection and may reveal useful signs. Although definitive diagnosis cannot be made based on imaging features alone, the use of a combination of epidemiologic, clinical and imaging findings may permit the formulation of an adequate differential diagnosis.

Fibrosing Mediastinitis: Uncommon Life-threatening Complication of Histoplasmosis

Histoplasmosis involving mediastinum is very rare which can present as a mediastinal mass or fibrosing mediastinitis. Fibrosing mediastinitis can be life-threatening if left untreated due to the involvement of the surrounding visceral and vascular structures. We present an interesting case of fibrosing mediastinitis due to histoplasmosis presented with palpitations, chest pain and dyspnea. The patient had mediastinal and hilar lymphadenopathy with calcification on chest imaging. The patient was diagnosed on lymph node biopsy and treated with antifungals.

[Acute and chronic mediastinitis]

BACKGROUND

A systematic approach to the etiology and possible course of acute mediastinitis is a prerequisite for adequate diagnostics and therapy. Chronic mediastinitis represents a rarity in the clinical practice.

MATERIAL AND METHOD

A selective literature search was carried out.

RESULTS

An acute infection of the mediastinum occurs after perforation of mediastinal structures, such as the esophagus and trachea mostly of iatrogenic origin and as descending necrotizing mediastinitis (DNM) from oropharyngeal foci. The mortality rate of esophageal injuries, irrespective of the cause is currently given as 12 %. A DNM results from an unobstructed spread along the cervicothoracic spaces and is a severe infection which manifests as a clinical picture of sepsis. The mortality rate given in the currently available literature is 14 %. Chronic mediastinitis is a very rare condition which is characterized by the proliferation of fibrous and collagenous tissue in the mediastinum. Whereas the pathogenesis remains unclear, there are indications for a Histoplasma capsulatum infection as the causal link. The prognosis is good.

CONCLUSION

After perforation of the esophagus or trachea there is always the risk of an infection of the mediastinum; therefore, the diagnosis is followed by further evaluation and early therapy. The DNM can cause unspecific symptoms of sepsis without an obvious focal point. It is important to be aware of a possible correlation between an oropharyngeal center of infection and mediastinitis in order to initiate appropriate diagnostic imaging in cases with the slightest suspicion. Chronic mediastinitis is a rare condition with varying courses and can be difficult to diagnose. An histological clarification for distinction from malignant diseases appears to be a sensible approach.