Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Pathophysiology | Etiology | Clinical features | Diagnostic criteria | Laboratory | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Tsang P. Littoral cell angioma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/spleenlittoralcellangioma.html. Accessed January 23rd, 2021.
Definition / general
- Rare benign splenic vascular tumor
- Originates from littoral cells lining splenic red pulp sinuses
Essential features
- Strong association with diverse immunologic and neoplastic disorders
- Dual endothelial and histiocytic differentiation of tumor cells, similar to normal splenic littoral cells
Terminology
- Littoral cell angioma of the spleen
ICD coding
- ICD-10: D73.89
Epidemiology
- Median age: 50 years (range 1 - 77 years)
- M = F (Int J Clin Exp Pathol 2015;8:8516)
Sites
- Unique to the spleen
Pathophysiology
- Immunodysregulation postulated to explain clinical association with various malignancies or immune / autoimmune disorders (Histopathology 2016;69:762)
Etiology
- Unknown etiology
Clinical features
- Almost always benign with exceedingly rare malignant transformation
- 50% asymptomatic (World J Gastroenterol 2015;21:6660)
- 50% present with splenomegaly, hypersplenism associated thrombocytopenia and anemia, abdominal pain, fever or weight loss (Histopathology 2016;69:762, World J Gastroenterol 2015;21:6660)
- 36% associated with immune / autoimmune / metabolic disorders, such as Crohn's disease or immune thrombocytopenic purpura (Blood 2017;129:1564)
- 40 - 60% associated with malignancies, such as colonic adenocarcinoma, pancreatic tumor, lung carcinoma, renal cell carcinoma, lymphoma, myelodysplasia, aplastic anemia or testicular seminoma (Histopathology 2016;69:762)
Diagnostic criteria
- Splenomegaly with nodules comprising benign tortuous vascular channels
- Dual endothelial and histiocytic immunophenotype lacking CD34
Laboratory
- Thrombocytopenia, anemia in subset of patients
Radiology description
- Enlarged spleen
- Ultrasound varies from heterogeneous echotexture without specific nodules to hyperechogenic, hypoechogenic or isoechogenic lesions
- CT shows solitary or multiple hypoattenuating nodules (BMJ Case Rep 2015 Nov 24;2015)
- MRI shows hypodense lesions on T1 and T2 weighted scans due to hemosiderin (Int J Clin Exp Pathol 2015;8:8516)
Prognostic factors
- Typically benign with excellent prognosis postsplenectomy
- Increased risk of malignant transformation with massive splenomegaly (> 1500 grams or > 20 cm long) (Minerva Chir 2014;69:229)
Case reports
- 38 year old man with splenic, renal and hepatic cysts (Arch Pathol Lab Med 2001;125:1505)
- 43 year old man with prior pulmonary sarcoidosis (World J Surg Oncol 2011;9:106)
- 45 year old man with obstructive jaundice (Indian J Pathol Microbiol 2012;55:109)
- 46 year old women and 52 year old man (Chin Med J (Engl) 2011;124:3423)
- 58 year old woman with large solitary littoral cell angioma (J Clin Imaging Sci 2012;2:69)
- 60 year old man with rapid increase in size of spleen (Rare Tumors 2010;2:e17)
- 61 year old woman with metastasis to the liver treated with chemotherapy (Medicine (Baltimore) 2018;97:e0378)
Treatment
- Splenectomy
Gross description
- Solitary or multiple distinct splenic nodules
- Minute to large nodules of variable consistency
- Various colors (yellow / brown / red / black) depending on degree of necrosis, cyst formation, thrombi and fibrosis (Int J Clin Exp Pathol 2015;8:8516)
- Spongy / cystic (J Cytol 2017;34:121)
Microscopic (histologic) description
- Proliferation of anastomosing, tortuous, blood filled vascular channels (Int J Clin Exp Pathol 2015;8:8516)
- Irregular channel lumina, often with papillary projections and cystic spaces
- Lined by tall endothelial cells with variable hemophagocytosis (BMJ Case Rep 2015 Nov 24;2015)
- Sloughing of endothelial cells into vascular spaces
- No sclerosis or cytologic atypia
Microscopic (histologic) images
Cytology description
- 3 dimensional, bland appearing, epithelioid foamy cells with low nuclear:cytoplasmic ratio (J Cytol 2017;34:121)
- May contain intracytoplasmic hemosiderin pigment
Positive stains
Molecular / cytogenetics description
- No specific molecular findings
Differential diagnosis
- Angiosarcoma:
- Atypical sarcomatous cells with hyperchromatic nuclei and CD34 positivity
- Frequent tumor necrosis
- Hamartoma:
- Disorganized blood vessels with entrapped adipocytes
- CD8+
- Splenic littoral cell hemangioendothelioma:
- Typically mild to moderate cytologic atypia
- May have solid areas
- Potentially malignant or metastasizing
- Kaposi sarcoma:
- Hemangioma:
- Usually asymptomatic, incidental finding
- Single layer of bland endothelial cells with CD34 positivity
- Hemangiopericytoma:
- Lymphangioma:
- Cystic, malformed lymphatic channels, often subcapsular
- Attenuated endothelial lining
Additional references
Board review style question #1
Board review style answer #1
B. CD34 is negative, even though other vascular endothelial cell associated markers are positive in littoral cell angioma.
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Board review style question #2
Which of the following statements is true about littoral cell angioma?
- Hypersplenism related anemia or thrombocytopenia is a common finding
- It is pathogenetically linked to human herpesvirus 8 (HHV8)
- It originates from the white pulp vascular lining cells of the spleen
- Malignant transformation is common among middle aged and elderly patients
Board review style answer #2
A. Hypersplenism related anemia or thrombocytopenia is a common finding. Hypersplenism in patients with littoral cell angioma can cause entrapment of RBCs and platelets in the spleen, leading to anemia and thrombocytopenia.
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