Reappraisal of surgical decision-making in patients with splenic sclerosing angiomatoid nodular transformation: Case series and literature review

Table 1 Characteristic of three patients with sclerosing angiomatoid nodular transformation

No.	Age (yr)	Sex	Indication	Symptoms	Size	CT		MRI		PET	Follow up	Surgery
						A phase	V phase	T1/T2	Contrast
1	48	M	Diagnostic splenectomy, for Atypical hemangioma MRI pattern, suspect lymphoma	8 kg loss in 2 yr; left abdominal painFatigue	5.5 cm	Septate enhancement	Mild progressing peripheral enhancement with centrally remained iso-hypodense	Iso-hypodense/iso-hypodense	Heterogenous gradual enhancement and diffusion restriction	Nil	2 mo	Open
2	61	F	Diagnostic splenectomy, for elevated CA19-9, malignancy cannot be rule out	Nil	4.1 cm	Mild enhancement	Mild progressing peripheral enhancement with centrally remained iso-hypodense	Iso-hypodense/hypodense	Mild peripheral enhancement	Nil	6 mo	Laparoscopy
3	52	M	Diagnostic splenectomy, for suspect lymphoma splenic involvement1	Nil	3.5 cm	Peripheral enhancement	Nil	Nil		Diffuse mild hypermetabolism at spleen (2SUVmax = 4.2)	4 mo	Laparoscopy

¹Underlying with B-cell non-Hodgkin lymphoma, Ann Arbor stage IV, IPI score 2, suspected marginal zone lymphoma, status post R-CHOP (VI, 2019/1/7-2019/07/19).

²SUVmax: maximum standardized uptake value.

SUV: Standardized uptake value; CT: Computed tomography; MRI: Magnetic resonance imaging; PET: Positron emission tomography; Non contrast CT: Iso-hypodense.

Table 2 Comparison of Image characteristics among common splenic tumor

	Tumor	Tumor shape, features, and characteristics	MRI T1	MRI T2	CT/MRI enhancing pattern	Other image characteristics probably aid diagnosis
Benign	SANT	Well-circumscribed, commonly lobulated, solitary mass	Iso-hypointense	Hypointense	Spoke-Wheel pattern; Poor enhancement	PET/CT: Low FDG accumulation
	Hemangioma	Single nodule; multiple nodules; diffuse masses enlarging the spleen	Hypointense	Hyperintense	Homogenous or peripheral enhancement	Mostly small, asymptomatic, and slow growth
	Cyst	Cystic lesion	Hypointense	Hyperintense	No enhancement	Ultrasound: Thin wall, anechoic, peripheral brightly echogenicity, and distal shadows due to wall calcification
Malignant	Systemic lymphoma	Homogenous splenomegaly; Infiltrative miliary lesions (1-5 mm); Multifocal lesions (2-10 cm); Uncommon solitary lesions (7-14 cm)	Isointense	Hypointense	Poor enhancing	Splenomegaly; Splenic infarct; PET: Intense heterogenous FDG activity; Extra-splenic findings: Hepatomegaly, lymphadenopathy
	Primary splenic lymphoma	Solitary mass > uncommonly Splenomegaly	Isointense	Hypointense	Poor enhancing	Central necrosis
	Metastasis	Variously	Iso-hypointense	Hyperintensity	Similar to the primary tumor	PET/CT: FDG-avid tumor; Poorly marginated; Heterogenous

CT: Computed tomography; MRI: Magnetic resonance imaging; PET: Positron emission tomography; FDG: Fluorodeoxyglucose.

Table 3 Indication list of splenectomy proposed for splenic tumors

Imaging features	Rationale for splenectomy
Benign tumor: Cyst; Hemangioma; SANT; other	Symptom-relief
	Probable splenic rupture
	Increasing tumor size or numbers
	Rule out malignancy with atypical image features
	Patient desire
Lymphoma	Symptom-relief
	Treatment for cytopenia without heavy bone marrow infiltration
	Diagnosis for tissue proof to determine the nature of lymphoma
Angiosarcoma	Treatment
Metastasis	Total tumor free
	Debulking after chemotherapy
	Diagnosis and total tumor free for isolated splenic metastasis

SANT: Sclerosing angiomatoid nodular transformation.