B-cell lymphoblastic lymphoma patient presenting with life threatening ruptured mycotic aneurysm of internal iliac artery

Abstract

Mycotic aneurysm is defined as the dilatation of the vessel wall. It is a rare entity especially the mycotic pseudoaneurysm of iliac artery due to the underlying infection of the artery wall. Due to the nonspecific signs and symptoms there is often a delayed diagnosis that can lead to high morbidity and mortality. We present a case of a 4 year old patient with B-cell lymphoblastic lymphoma who developed a mycotic aneurysm of the right internal iliac artery while undergoing chemotherapy. The patient underwent the radiological imaging CT scan and MRI for nonspecific symptoms of fever, abdominal pain and lymphadenopathy and aneurysm was found on the scans. Patient health deteriorated fast and he died of cardiopulmonary complications before receiving any surgical or endovascular therapy. This case is unique in its kind as the fast and progressive nature can prove fatal. Therefore, the role of radiological imaging is crucial in making an early diagnosis that can improve the already poor prognosis of this clinical situation.

Introduction

A mycotic aneurysm is described as the dilatation of the vasculature particularly its walls [1]. William Osler originally named the term ‘mycotic’ to report the first case of aneurysm caused by a fungal infection [2]. There are multifactorial causes of mycotic aneurysm including traumatic or iatrogenic injury to vessels, immunocompromised state, endocarditis, osteomyelitis, and bacterial and fungal infections [1,2]. It afflicts the femoral artery, thoracic aorta, abdominal aorta, and the popliteal artery and there is rare involvement of iliac artery as well [2]. The incidence of aneurysm caused by infections is reported to be 3.3% and the involvement of aorta and iliac arteries make up to 0.6%-1.3% of all such aneurysms [3]. There is often a delayed diagnosis due to the nonspecific nature of symptoms such as fever, pain and leukocytosis and it can lead to morbidity and mortality [4]. Use of imaging modalities such as computerized tomography (CT) scans, magnetic resonance imaging (MRI), or digital subtraction angiography (DSA) is therefore crucial for screening and diagnosis [4,5]. The treatment is usually the removal of the source of infection and surgical revascularization using the endovascular techniques [2,3]. After a thorough literature search on PubMed, Scopus, and Google Scholar, we conjecture that this is the first case to be reported from Pakistan describing the rupture of mycotic aneurysm in a B cell lymphoblastic lymphoma patient and the radiological findings that can help clinicians in making a diagnosis.

Case presentation

A 4-year-old boy presented to the medical oncology outpatient department of our hospital in September, 2023 with a 5 month history of generalized lymphadenopathy associated with high grade fever. In July, 2023 left inguinal lymph node biopsy was performed outside hospital due to enlarged inguinal and axillary nodes from 3 months and a sample was received in our hospital and histopathology report showed B cell lymphoblastic lymphoma in histopathology report in August, 2023. The physical examination revealed bilateral axillary, cervical and inguinal lymph nodes enlargement. The complete blood count (CBC) on admission showed platelet count of 5000 /mcL, white blood cells (WBCs) 10,600 cells/mm3, hemoglobin (Hb) 11 mg/dl, and 21% blast cells. A critical alert was raised for low platelets. Five days after admission platelets were arranged and transfused. Repeat CBC showed improvement in platelet count up to 10,000 /mcL but next day again it dropped to 3000 /mcL for which another transfusion was given. On day 6 of admission computerized tomography (CT) of neck, chest, abdomen and pelvis with contrast was performed under sedation as clinicians wanted to confirm any intraabdominal lymphadenopathy as there was cervical, axillary and inguinal lymphadenopathy on examination (Fig. 1).

Fig. 1.

Axial CT images of abdomen and pelvis after intravenous iodinated contrast administration showing (A) splenomegaly (arrow) and left para aortic lymphadenopathy (arrowhead), (B) with enlarged left common iliac lymph nodes (arrow).

CT showed hepatosplenomegaly, bilateral axillary, retroperitoneal and inguinal lymphadenopathy. On day seven of admission intrathecal 3 drug regimen chemotherapy was started in the operation theatre under general anesthesia. Bone marrow biopsy and aspiration done from right iliac crest in operation theatre on same day for further diagnosis of B cell lymphoblastic lymphoma and leukemia. Bone marrow aspirate showed acute leukemia with 86% blast cells.

Next day after CT was performed patient developed right lower quadrant pain which was thought to arise from right inguinal lymphadenitis or acute appendicitis was suspected. Ultrasound was discussed but not performed because there was a suspicion of bowel obstruction or bowel perforation, rather a plain radiograph of the abdomen in erect position was performed. It was unremarkable which ruled out bowel obstruction or perforation. Two more platelet transfusions were given due to low platelet count after which the patient was discharged at platelet count of 11,000 /mcL.

Three days after discharge, the patient presented in the emergency department with tachycardia, tenderness in right iliac region and low platelet count of 2,000/ mcL for which two platelets transfusions were given in the next 2 days with platelet count of 20,000 /mcL.

Patient developed high grade fever and tenderness at the bone marrow biopsy site. Biopsy site cellulitis was suspected, for which intravenous piperacillin-tazobactam was given. Blood cultures were performed which revealed E.coli bacteria. The patient was discharged after initial stabilization.

Next day after discharge the patient presented in emergency with generalized tonic clonic seizures with bilateral fixed dilated pupils with Glasgow coma scale (GCS) of 3/10. Patient was shifted to intensive care unit (ICU), intubated with endotracheal tube (ETT) and mechanical ventilation given. CT brain was performed which showed intracranial bleed and this was followed by MRI brain with contrast on the same day (Fig. 2).

Fig. 2.

(A) Axial T2 weighted MR image of brain at the level of body of lateral ventricles is showing T2 hyperintense lesion in the right parietal white matter (arrow). (B) T1 weighted post gadolinium MR image of the brain shows no contrast enhancement within the lesion in right parietal white matter (arrow). (C) Scattered areas of blooming artifacts (arrow) seen on Susceptibility weighted imaging (SWI) representing scattered internal micro hemorrhages or mineral deposition in case of fungal infection. (D) Diffusion weighted imaging (DW) and (E) Apparent diffusion coefficient (ADC) map shows diffusion restriction of the lesion appearing high on DW imaging (arrow) and low signal intensity (arrow) on ADC map. (F) On FLAIR sequences lesion appears hyperintense (arrow).

Patient became breathless for which X-ray chest was done which showed spontaneous pneumothorax for which 12 Fr chest tube was inserted which was removed after 3 days with resolution of pneumothorax. The patient's GCS improved to 15/15 after which he was extubated. Nasogastric feed was started. Tracheal aspirate was obtained which revealed aspergillus hyphae.

Patient stayed in the ICU for 6 days after which he was shifted to a ward in stable condition. Patient developed right iliac fossa swelling for which ultrasound was performed which only showed right sided hydronephrosis.

CT thorax with intravenous contrast was performed which showed interval development of multifocal cavitary lesions in both lungs (Fig. 3). These findings were suggestive of fungal infection.

Fig. 3.

Axial CT images of the thorax in lung windows at the level of carina (A) and inferior pulmonary veins (B) show interval development of consolidative patches with internal cavitation and surrounding ground glass haze, in right middle and lower lobes (white arrows) suggestive of fungal infection.

MRI brain with intravenous contrast was repeated (Fig. 4). It revealed interval enlargement of enhancing and diffusion restricting lesions in the right parietal/occipital lobes at the previous site of abnormal intensity signals. Features were suggestive of disease progression.

Fig. 4.

(A) Axial T2 weighted image show interval enlargement of the heterogeneous signal in the right posterior parietal lobe (arrow). (B) T1 weighted post gadolinium MR image of the brain show peripherally enhancing lesion (arrow). (C) Scattered areas of blooming artifacts (arrow) seen on SWI representing scattered internal micro hemorrhages or mineral deposition in case of fungal infection. (D) DW and (E) ADC map shows diffusion restriction of the lesion appearing high on DWI (arrow) and low on ADC map (arrow) and this is appearing hyperintense on (F) FLAIR sequences (arrow).

Chest x-ray showed right upper lobe consolidation suggestive of disease involvement. Patient was again discharged in vitally stable condition. Three days after discharge the patient presented in emergency with GCS of 4/15 and blood pressure of 150/100 mmHg. Patient was admitted and intubated in ICU with mechanical ventilation with 10 L of oxygen requirements. Transthoracic echocardiography was performed which showed severe bilateral systolic dysfunction with ejection fraction of 34 %. Captopril, spironolactone and furosemide were given to control hypertension. CBC showed low HB of 4.6g/dL and platelet count of 21000 / mcL. Two mega units of platelet and packed RBCs transfusion were given. There was a further increase in right inguinal region swelling for which CT abdomen and pelvis was performed which showed ruptured right internal iliac artery mycotic pseudoaneurysm with active internal hemorrhage and hematoma formation causing mass effect and bilateral hydronephrosis and hydroureter (Fig. 5). Critical alert was raised due to the rupture of the aneurysm.

Fig. 5.

Coronal CT images of the abdomen and pelvis with contrast (A & B) show right internal iliac artery pseudoaneurysm (arrowhead) with adjacent hyperdense hematoma (arrows).

Urgent CT brain with contrast was advised to look for any intraparenchymal hemorrhage. CT revealed interval development of acute intraparenchymal hemorrhages with intraventricular extension, midline shift, vasogenic edema and severe hydrocephalus. Findings were suggestive of angioinvasive fungal infection (Fig. 6).

Fig. 6.

Axial unenhanced images of the brain (A & B) showed interval development of intraparenchymal hemorrhages (white arrow in A) in the right fronto-parietal lobe with surrounding marked vasogenic edema (arrowheads in A) and associated intraventricular bleed (white arrows in B).

Patient condition deteriorated and there were absent brainstem reflexes. Patient family was informed about the condition of the patient and consent for withdrawal of life support care was obtained. Patient death was declared after 3 days of admission in ICU. Possible cause of death was massive intracranial bleed, persistent E. coli and fungal infection with ruptured mycotic aneurysm.

Discussion

Mycotic aneurysm was initially described by William Osler in a patient who presented with symptoms of fever, chills, and pneumonia and later died, and on autopsy report fresh fungal vegetation were found on the aortic valve and the four aortic arch aneurysm [6]. The terminology is often deceiving as fungus being the only cause of mycotic aneurysm. However, there are multiple risk factors that lead to mycotic aneurysm which includes traumatic or iatrogenic injury to vessels, immunocompromised state, endocarditis, osteomyelitis, and bacterial and fungal infections [1,2]. Omofoye et al. [7] also reported the association of aneurysm in cancer patients. We reported a rare case of B-cell lymphoblastic lymphoma patient who developed mycotic aneurysm of the right internal iliac artery while undergoing chemotherapy.

The incidence of aneurysm caused by infections is reported to be 3.3% and the involvement of aorta and iliac arteries make up to 0.6%-1.3% of all such aneurysms [3]. Mycotic aneurysm is notorious to afflict different arteries the femoral artery, thoracic aorta, abdominal aorta, and the popliteal artery and there is also a rare involvement of iliac artery as well. Moreover, the involvement of peripheral arteries is usually less than that of abdominal aorta and with the use of advance antibiotics this has also become low [2,6]. In our case the mycotic aneurysm was associated with the iliac artery.

The clinical presentation is highly variable and is dependent on various factors which includes the severity of infection, patient comorbidities, and site of the aneurysm. Due to this high variability clinicians should speculate the presence of an infected aneurysm in patients who had previous history of undergoing any invasive procedures, immunocompromised states, malignancy, intravenous drug users, or endocarditis. This case was presented in a 4-year-old boy who came with a history of B cell lymphoblastic lymphoma. There is usually a diagnostic dilemma due to the nonspecific and vague nature of the disease process. Many symptoms such as fever, pain and leukocytosis that are common for several other conditions generally may be present and this can lead to the wrong diagnosis. Henceforth, a wrong or delayed diagnosis can lead to morbidity and mortality [4,6]. In our reported case the patient presented with complaints of fever, tenderness and lymphadenopathy after the chemotherapy was started.

The use of radiological imaging is thus paramount in making correct and urgent diagnosis of this rare disease process which can provide the clinicians with an opportunity to do a quick intervention that can improve the poor outcome of disease process. There is a frequent use of CT scans, MRI, or positron emission tomography scans (PET-CT). CT and MRI both show a higher sensitivity and specificity and can isolate complex cases and make a diagnosis [4,5]. In our case the patient CT scan demonstrated the internal iliac pseudoaneurysm. MRI brain was advised that revealed scattered internal hemorrhages. Later in the disease progression CECT was performed which showed intraparenchymal hemorrhage with intraventricular extension.

The mainstay of treatment for the mycotic aneurysm is aimed at the removal of underlying source of infection and curtailing its spread. Prolong use of antibiotics for a duration of about 4-6 weeks is required or until the blood cultures are negative [2,8]. Whether to use the surgical treatment or go for the endovascular treatment depends upon the condition of the patient. Endovascular surgery has potential benefits over the open surgical approach in its chief benefits of reducing morbidity and mortality that are associated with potential complications of open surgery which includes blood loss, general anesthesia, and ischemia [6]. Our case underwent intrathecal 3 drug regimen chemotherapy under general anesthesia. Blood transfusion and platelet transfusions were give due to low platelet count. His health deteriorated and he was admitted to the ICU, intubated and given mechanical ventilation. Multidisciplinary review was taken from neurosurgeon and vascular surgeon and all surgical interventions were deferred due to poor condition and a low GCS. Meanwhile, the patient developed severe cardiac dysfunction and died due to cardiopulmonary arrest.

Much information is available on the mycotic aneurysm and its complications, we have tried our best to describe the clinical course of the disease process in a cancer patient, its radiological findings, and the fast and rapidly deteriorating nature that can prove fatal if not timely diagnosed.

Conclusion

Mycotic aneurysms is a rare and potentially life-threatening vascular condition that imparts a significant challenge to healthcare providers due to their complex etiology, varying clinical presentations, and the need for a multifaceted approach to management. Although its incidence is rare and it can be easily mistaken for other diseases due to similar presentation, it is a dreadful and lethal complication leading to fatal outcomes if not timely diagnosed and managed.

Patient consent

Written informed consent for publication was obtained from the parents.