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Radiol Case Rep
Radiol Case Rep
Radiology Case Reports
1930-0433
Elsevier

S1930-0433(24)00797-0
10.1016/j.radcr.2024.08.013
Case Report
Ascites revealing peritoneal amyloidosis and IgG kappa multiple myeloma: A case report
Sabri Samia sabri.samia90@gmail.com
ab⁎
Bachir Houda ab
Hamaz Siham ab
Bennesser Habiba Alaoui ab
Serraj Khalid ab
a Faculty of Medicine and Pharmacy, Mohammed First University, Oujda, Morocco
b Department of Internal Medicine, Univeristy Hospital Mohammed Vl, Oujda, Morocco
⁎ Corresponding author. sabri.samia90@gmail.com
03 9 2024
11 2024
03 9 2024
19 11 54655470
7 5 2024
2 8 2024
4 8 2024
© 2024 The Authors. Published by Elsevier Inc. on behalf of University of Washington.
2024

https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
AL amyloidosis is a rare systemic disease characterized by the deposition of amyloid protein in various organs, including the kidneys, heart, peripheral nervous system, digestive tract, skin, and muscles. Peritoneal involvement in AL amyloidosis is exceptionally rare. We present a unique case of AL amyloidosis with concurrent cardiac, cutaneous, and peritoneal manifestations. The patient initially presented with ascites and respiratory symptoms. An etiological workup revealed multiple myeloma as the underlying cause. This case highlights the importance of considering AL amyloidosis in the differential diagnosis of peritoneal ascites, providing valuable insights for radiologists in recognizing atypical presentations of this disease.

Keywords

Peritoneal ascites
Differential diagnosis
Radiology
Imaging modalities
Case report
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pmcIntroduction

Amyloidosis is a group of disorders characterized by the extracellular deposition of insoluble protein fibrils, known as amyloid, in various tissues and organs [1,2]. These deposits can occur without causing significant clinical symptoms, or they may lead to severe dysfunction depending on the extent and location of the amyloid accumulation. Commonly affected organs include the kidneys, heart, liver, and nervous system, where amyloid deposition can result in substantial clinical consequences [1]. However, peritoneal involvement in amyloidosis is an exceptionally rare phenomenon, with limited cases reported in the literature.

The rarity of peritoneal amyloidosis poses a significant diagnostic challenge, as its clinical presentation may mimic more common conditions such as liver disease, nephrotic syndrome, or malignancies. The identification and diagnosis of amyloidosis involving the peritoneum require a high index of suspicion and often necessitate the use of advanced imaging modalities and histopathological confirmation [[1], [2], [3], [4]].

In this case report, we present a 71-year-old male who presented with progressive abdominal distension and respiratory symptoms. Upon thorough investigation, the underlying etiology was identified as amyloidosis with peritoneal involvement, secondary to multiple myeloma. This case is particularly notable due to the atypical presentation and the involvement of multiple organ systems, including the heart and skin, alongside the peritoneum.

Our report aims to enhance the understanding of this rare manifestation of amyloidosis and provide insights into the diagnostic process. By sharing our experience, we hope to contribute to the existing body of knowledge and aid clinicians in recognizing and managing similar cases. The case underscores the importance of considering amyloidosis in the differential diagnosis when encountering patients with unexplained ascites and other systemic symptoms

Case presentation

We report the case of a 71-year-old male chronic smoker with a 50 pack-year history, presented with abdominal distension among a background of general deterioration. At his first clinical presentation, he was alert, well oriented in time and space, with a Glasgow Coma Scale (GCS) of 15/15, he was also apyretic.

On physical examination, the patient was bedridden, malnourished, and showed various dermatological manifestations including painless flesh-colored papules and nodules in the pelvic region, ecchymotic purpura (Fig. 1, Fig. 2), lower limb oedema, and a distended abdomen with dullness on percussion. Examination of the pleuropulmonary system revealed we noted decreased vocal fremitus and breath sound evoking a condensation pulmonary syndrome.Fig. 1 Painless flesh-colored papules in the pelvic region.

Fig 1:

Fig. 2 Purpuric lesion located on the right hand.

Fig 2:

Examination of the ascitic fluid indicated an exudative profile (albumin = 35 g/l) with a predominant cellular composition consisting mainly of lymphocytes (569 white cells per m3, comprising 60% lymphocytes). Despite comprehensive assessments including cultures and assays for neoplastic cell detection such as quantiferon and antinuclear antibodies, all yielded negative results.

An injected CT-scan was conducted revealing pleural effusion, moderate ascites, peritoneal thickening, and infiltration of abdominal fat (Fig. 3). Histopathological analysis of peritoneal biopsies disclosed Congo red staining under polarized light, suggestive of amyloid deposits (Fig. 4).Fig. 3 CT scan with contrast injection showing hypertrophy of the peritoneal layers.

Fig 3:

Fig. 4 Amyloid deposits with positive Congo red staining.

Fig 4:

Analysis of pleural fluid revealed a transudative profile (albumin = 24 g/l). Investigations into the etiology of the transudative pleural effusion, including 24-hour proteinuria and liver function tests, returned normal results.

Cardiac ultrasound unveiled findings consistent with hypertensive cardiomyopathy, encompassing biventricular hypertrophy, subnormal ejection fraction, granular and sparkling myocardial appearance, interatrial septum involvement, and pericardial effusion. Biopsy of pelvic lesions confirmed the presence of amyloid deposits. Laboratory assessments for amyloidosis demonstrated a normal complete blood count, CRP level of 18 mg/l, creatinine concentration of 6.78 mg/dL, negative 24-hour proteinuria, and normal liver function tests. Serum protein electrophoresis and immunoelectrophoresis disclosed monoclonal gammopathy characterized by free kappa light chains (IgG) (Fig. 5, Fig. 6), while Bence-Jones proteinuria was absent. Bone marrow examination revealed 35% plasma cell infiltration, thereby confirming the diagnosis of indolent IgG kappa multiple myeloma with AL amyloidosis.Fig. 5 Serum protein electrophoresis: Capillary electrophosis Sebia Technique.

Fig 5:

Fig. 6 Serum immunofixation (In agarose gel SEBIA).

Fig 6:

Treatment commenced with the VCD protocol (bortezomib, cyclophosphamide, dexamethasone) in conjunction with diuretics. Nevertheless, the patient's clinical condition rapidly deteriorated, presenting as global cardiac decompensation marked by oedema, ascites, and bilateral pleural effusion, ultimately culminating in demise 3 months postdiagnosis despite aggressive intervention.

Discussion

Peritoneal amyloidosis is exceptionally rare and often presents with minimal symptoms. This case reveals a unique instance of kappa light chain myeloma associated with both cardiac and cutaneous amyloidosis. Systemic amyloidosis comprises a group of diverse clinical conditions characterized by the extracellular deposition of amyloid substances, which are insoluble fibrillar proteins found in various tissues and organs. Three primary types of amyloid substances are distinguished (Table 1): AA substance, derived from serum amyloid A (SAA) secreted by the liver during inflammatory states and subsequently converted into AA substance by monocyte cells; AL substance, originating from the transformation of immunoglobulin light chains under proteolytic enzyme influence [3]; and transthyretin, which is the most common hereditary form. Transthyretin is a polypeptide chain consisting of 127 amino acids synthesized by the liver, where a single amino acid residue substitution can lead to an amyloidogenic variant. The diagnosis of other dominant hereditary amyloidosis varieties is primarily considered when renal (lysozyme, fibrinogen, apolipoprotein AI and AII) involvement is observed, but also in cases of predominant hepatic or cardiac amyloidosis [3].Table 1 Classification of systemic amyloidosis [14].

Table 1:Amyloid protein	Precursor protein	Amyloidosis	
AA	Serum amuloid A	Reactive: infections, chronic inflammation, tumors	
AL	Immunoglobulin Light chain	Primitive, associated with dysglobulinemia	
AH	Immunoglobulin Heavy chain		
ATTR	Transthyretin variants	Hereditary	
A Gel	Gelsolin	Hereditary	
A Fib	Fibrinogen A α chain	Hereditary	
A Lys	Lysozyme	Hereditary	
A β2M	β2‐microglobulin	Associated with chronic end-stage renal failure	
A Cys	cystatin C	Cerebral hemorrhage
Hereditary	
A β	Β amyloid precursor protein	Alzheimer's disease, Down Syndrome, cerebral hemorrhage	
A Scr	scrapie prion protein	Spongiform encephalopathy, Gerstmann-Straussler-Scheinker syndrome	
A Cal	Procalcitonin	Associated with medullary thyroid cancer	
AANF	Atrial natriuretic factor	isolated atrial amyloidosis	
IAPP	Islet Amyloid Polypeptide	Type 2 diabetes, insulinoma	
AapoAI	A I apoliprotein	Hereditary	
AapoAII	AII apolipoprotein	Hereditary	

Peritoneal amyloidosis is exceedingly rare and typically asymptomatic [4]. Ascites occurs in only 20% of patients, highlighting the necessity for a thorough etiological assessment for any ascites (Fig. 7). Two types of noncirrhotic ascites can be differentiated: one related to peritoneal involvement (such as infection, carcinosis, or seritis) and another secondary to noncirrhotic portal hypertension, primarily involving vascular or lymphatic pathologies (Table 2). CT scan results are not always specific and can sometimes mimic peritoneal carcinosis, presenting as nodular or diffuse lesions. Nodular lesions appear as mesenteric masses and localized thickening of the intestinal wall, while diffuse lesions show as widespread peritoneal thickening with amorphous or irregular calcifications [4]. Our patient's scan demonstrated peritoneal nodules and infiltration of abdominal fat, emphasizing the need for surgical biopsy to confirm the diagnosis of amyloidosis and exclude other differential diagnoses such as chronic infections, carcinosis, and other infiltrative diseases [4].Fig. 7 Diagnostic approach when facing an ascites.

Fig 7:

Table 2 Pathologies causing ascites.

Table 2:Origin of ascites	Underlying disease	
Liver	Cirrhosis, Thrombosis of subhepatic veins or the portal vein, Liver cancer	
Heart	Cardiac failure, constrictive pericarditis	
Kidney	Nephrotic syndrome	
Malignant	Peritoneal carcinomatosis, Mesothelioma, Lymphoma	
Infectious	Tuberculosis, pyogenic bacterial peritonitis, Chlamydia infection, Whipple disease, Fungal or parasitic infections,	
Connectivitis and systemic disease	Lupus, Antiphospholipid syndrome, Gougerot disease, Sarcoïdosis	
Other	Chylous ascites, pancreatic ascites, Dermong Meig syndrome, ovarian hyperstimulation, Hypothyroidism	

Amyloid cardiomyopathy often presents as heart failure with preserved ejection fraction (restrictive cardiomyopathy), characterized by symptoms such as dyspnea and edema. Angina, presyncope, and syncope may also be present. In our patient, symptoms were initially attributed to hypertensive cardiomyopathy. Echocardiography revealed hypertensive cardiomyopathy, biventricular hypertrophy, and reduced left ventricular ejection fraction. Although cardiac magnetic resonance imaging offers higher sensitivity and specificity compared to echocardiography, its use may be limited by amyloid nephropathy [5]. Myocardial biopsy remains the gold standard for diagnosing cardiac amyloidosis. However, typical echocardiographic findings in a patient diagnosed with amyloidosis by a nonmyocardial tissue biopsy can confirm cardiac involvement without the need for myocardial biopsy, as observed in our case.

Skin involvement is commonly observed in AL amyloidosis, with an association rate of 20% to 30% according to various studies [6,7]. Symptoms include bruising and purpuric lesions on the eyelids, face, neck, armpits, and thighs. These are primarily due to amyloid deposits infiltrating the dermal vessel walls, sometimes presenting as nodules or yellowish papules, which may coalesce into a pseudo-sclerodermiform appearance. Diagnosis of amyloidosis is histological, based on biopsy analysis from affected organs or noninvasive biopsies (such as subcutaneous fat or accessory salivary glands) and detection of amorphous deposits stained with Congo red, demonstrating dichroism and birefringence under polarized light.

Regarding associations with multiple myeloma, the most frequent are with light chain myeloma, IgG myeloma, and IgA myeloma. The factors contributing to the amyloidogenic potential of different monoclonal light chains are not fully understood. AL amyloidosis associated with plasma cell dyscrasia often indicates a benign condition (monoclonal gammopathy of undetermined significance) and, in approximately 4% of cases, a malignant condition (such as myeloma or Waldenström's disease) [8,9].

Treatment for systemic AL amyloidosis primarily involves chemotherapy aimed at eliminating the B clone responsible for secreting amyloidogenic light chains. In 90% of cases, these are plasma cells, which justifies the use of agents employed in myeloma treatment. The current strategy in France involves initial treatment based on the severity of cardiac involvement, assessed using the Mayo Clinic score [10], followed by hematologic response. Stage I (without cardiac involvement) and II (with moderate cardiac involvement) patients are initially treated with M-Dex (melphalan, dexamethasone), with bortezomib added for nonresponders (dFLC decrease <50%) after 3 cycles in Stage I and after one cycle in Stage II. Patients with severe cardiac involvement (Stage III) receive immediate treatment with a combination of bortezomib, cyclophosphamide, and dexamethasone (VCD), a regimen that has demonstrated remarkable efficacy in recent series [11], aiming for the most complete and rapid response. The goal for all patients is to achieve the best hematologic response possible, with at least a very good partial response. Symptomatic treatment with diuretics and repeated therapeutic paracentesis can help alleviate symptoms of heart failure and nephrotic syndrome. dFLC: difference between the rate of monoclonal light chains and polyclonal light chains. Amyloidosis with multi-organ involvement generally has a poor prognosis, with a median survival of approximately 9 months [12]. The primary causes of death are infections, acute kidney injury, restrictive cardiomyopathy, and ischemic heart disease [13].

Conclusion

Amyloidosis is a multisystem disorder. However, peritoneal involvement remains unusual. Definitive diagnosis is histological through Congo red staining, exhibiting dichroism and birefringence under polarized light. The etiological diagnosis in these cases is often challenging, and the prognosis is severe.

Patient consent

I, Dr. Sabri Samia, confirm that informed consent has been obtained from the patient for the publication of their medical case report titled “Ascites revealing peritoneal amyloidosis and IgG kappa multiple myeloma: A case report.” The patient has been informed about the purpose of the publication, the potential disclosure of their medical information, and the measures taken to protect their anonymity. The patient has agreed to the publication without any coercion, and they understand the potential risks involved.

Competing Interests: The authors declare no conflicts of interest.
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