Sclerosing angiomatoid nodular transformation (SANT) of the spleen: a case report with FDG-PET findings and literature review

Two Rare Benign Lesions on 18F-FDG PET/CT: Peliosis Hepatis and SANT

Peliosis hepatis (PH) and sclerosing angiomatoid nodular transformation of the spleen are uncommon benign lesions. Diagnosis can be difficult in some patients. Herein, we present the case of a 28-year-old woman referred with abdominal pain who had spleen lesions. 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography revealed multiple non-FDG avid lesions in the liver and hypermetabolic lesions in the spleen. In addition, abdominal magnetic resonance imaging was performed. Histopathology revealed sclerosing angiomatoid nodular transformation in the spleen and PH in the liver.

Sclerosing angiomatoid nodular transformation of the spleen: multimodality imaging features and literature review

OBJECTIVE

The purpose of this study was to evaluate the CT and MRI findings, clinicopathologic features, and differential diagnosis of Sclerosing angiomatoid nodular transformation (SANT).

METHODS AND MATERIALS

Seven men and seven women with pathological diagnoses of SANT were included in this retrospect study. Patients underwent at least one radiological examination before surgery. The number, shape, margin, size, attenuation, signal intensity, homogeneity, and enhancing pattern of the lesion were evaluated by two abdominal radiologists independently. Immunohistochemistry reports were available for 11 patients. The immunoreactivity to the vascular markers CD8, CD31, and CD34 was assessed.

RESULTS

The 14 SANT patients (7 men, 7 women; mean age, 43.5 years; age range, 24-56 years) presented with a single lesion and showed no specific clinical symptoms. Among 14 patients, 12 patients underwent MR scan, 5 patients underwent CT scan and 3 patients underwent PET-CT. On CT, all 5 lesions showed hypodensity on non-contrast images and spoke-wheel enhancing pattern after contrast administration, and calcification was observed. On T2WI, 10 cases(83.3%)showed hypointensity and 2 cases (16.7%) showed hyperintensity with central hypointensity. On T1WI, 10 cases (83.3%) were isointense and 2 cases (16.7%) were slightly hypointense. 10 cases (83.3%) showed hypointensity on DWI and 2 cases (16.7%) showed slightly hyperintensity on DWI. After contrast administration, all 12 lesions showed progressive enhancement. 18 F-fluorodeoxyglucose (FDG) uptake in the tumor was seen in all three cases that underwent PET-CT. The maximum standardized uptake value (SUVmax) was 4.5, 5.1, and 3.8 respectively.

RESULTS

Apart from the progressive spoke-wheel enhancing pattern, DWI and ADC findings will add value to the diagnosis of SANT.

Imaging patterns in non-traumatic spleen lesions in adults-a review

The spleen is a complex organ involved in multiple physiological processes in the human body. Elective splenectomy is an uncommon operation, and the precise characterization of the lesion should be achieved to determine the risks and benefits of this operation accurately. Given the significant role of the spleen in homeostasis and the potential risks of the surgery itself and following sequelae such as infection susceptibility, accurate recognition, and classification of splenic lesions is required before surgery. This review provides an overview of malignant (e.g., lymphoma, angiosarcoma) and benign (e.g., cysts, hemangioma, hamartoma) splenic lesions that may warrant an elective splenectomy. Images from a cohort of adult patients undergoing isolated splenectomy for non-traumatic indications in a single center are provided. This review highlights the considerable overlap in imaging patterns between splenic lesions, splenic lesions masquerading as lesions in other organs, increased detection of asymptomatic splenic incidentalomas due to improvements in imaging modalities. This review also provides clinical correlations for each lesion, providing additional information to help clinicians differentiate between lesions and accurately identify diseases amenable to surgical management.

Sclerosing Angiomatoid Nodular Transformation (SANT): A Rare Splenic Tumor and Unusual Cause of Anemia

Patient: Male, 57-year-old

Final Diagnosis: Sclerosing angiomatoid nodular transformation (SANT) of spleen

Symptoms: Anemia

Medication:—

Clinical Procedure: Splenectomy

Specialty: Surgery

Sclerosing angiomatoid nodular transformation presenting with thrombocytopenia after laparoscopic splenectomy - Case report and systematic review of 230 patients

Background

Sclerosing angiomatoid vascular transformation (SANT) is a rare vascular disease of the spleen, which is difficult to diagnose due to its pre-intervention appearance of malignancy. Case Report: An 85-year-old male was transferred to our clinic for thrombocytopenia and splenic mass. A contrast enhanced abdominal CT and MRI showed nodular lesions, the largest 50mm in diameter, and several areas of heterogeneous contrast field involvement in the spleen parenchyma. Laparoscopic splenectomy was performed with normal range of platelet level. The patient's postoperative course was uneventful and he was discharged on the 6th postoperative day. Histopathology revealed SANT. The patient is now in the 18 th month of remission with platelet levels within normal range and with no recurrence.

Results

Between 2004 and April 2020, a total of 230 SANT patients who underwent laparoscopic or open splenectomy or biopsy were reported in the literature. Most patients were female (52.1%), and the median age was 46 years (9 weeks-85 years). Most patients were asymptomatic (56%). Open splenectomy was performed on 166 patients (72.1%),laparoscopic splenectomy on 35 patients (15.2%) and laparoscopic partial splenectomy on 15 patients (6.5%). The median operation time and spleen weight were 143 minutes (88-213) and 260gr (68-2,720), respectively. Median follow-up time was 12 months (0-166). No recurrence was seen in patients undergoing total splenectomy.

Conclusion

SANT is an unusual disease of the spleen. In the light of this systematic review, a minimally invasive method for total or partial splenectomy,specifically laparoscopy, can be preferred as the treatment of choice.

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SANT is a rare, benign vascular disease of the spleen.

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The correct diagnosis of SANT pre-intervention or preoperatively is a significant for treatment.

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Laparoscopic splenectomy is curative treatment for SANT.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: Lessons from a Rare Case and Review of the Literature

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is an extremely rare benign lesion. We herein report a case of asymptomatic SANT of the spleen in a middle-aged woman with early breast carcinoma and an undiagnosed splenic mass, which was successfully treated by laparoscopic splenectomy and diagnosed postoperatively. We also review the literature on SANT to help make knowledge more accessible when clinicians encounter a splenic tumor. The present case taught us the following lesson: the presence of a splenic lesion during follow-up for malignancy is not always indicative of metastasis. Therefore, SANT should be considered in the differential diagnosis.

Sclerosing Angiomatoid Nodular Transformation of the Adrenal Gland: A Case Report of a Novel Histopathological Entity

The finding of an indeterminate adrenal mass at radiological investigations is a challenge for physicians. Complex diagnostic work-up, periodic follow-up, or surgical intervention are therefore needed to rule out malignant lesions. Tertiary care hospitals are provided with ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and ¹⁸F-dihydroxyphenylalanine (¹⁸F-DOPA) PET, which aid in the characterization of indeterminate adrenal masses. Nevertheless, the histopathological examination may be required to exclude malignancy or rare etiologies. A 54-year-old woman presented to our clinic 6 months after a cerebral hemorrhage. She was hypertensive and had recently discovered a left adrenal mass of 15 mm during an abdominal ultrasound. Contrast-enhanced CT, following adrenal protocol, revealed a 14-mm adrenal mass without characteristics suggestive of an adrenal adenoma. Tumor markers were negative. Functional tests excluded hormone hypersecretion. An ¹⁸F-DOPA PET was negative. An ¹⁸F-FDG PET showed mild uptake of both the adrenal glands, with a more circumscribed pattern in the left one (maximum standardized uptake value = 4). As the clinical diagnosis was still indeterminate, we performed laparoscopic left adrenalectomy. The histopathological examination described a sclerosing angiomatoid nodular transformation (SANT) of the adrenal gland, a benign lesion already described as a rare occurrence only in the spleen. IgG4 levels were reduced. In conclusion, this is a report of a SANT of the adrenal gland, a novel entity that should be taken into consideration in the differential diagnosis of indeterminate adrenal masses at CT scan.

Sclerosing angiomatoid nodular transformation of the spleen (SANT) in a patient with clear cell carcinoma of the uterus: a case report

Background

Sclerosing angiomatoid nodular transformation of the spleen is a very rare benign vascular lesion recently described. Usually, sclerosing angiomatoid nodular transformation of the spleen is an incidental finding; the association with malignant tumors is extremely rare. To the best of our knowledge, we report the first case of sclerosing angiomatoid nodular transformation of the spleen associated with uterine clear cell carcinoma.

Case presentation

A 49-year-old Arabic woman presented to our institute with abdominal pain and distention. An abdominal computed tomographic scan was obtained, which showed a 14-cm uterine malignant tumor and a 4-cm isolated splenic nodule suggesting a metastatic lesion. The tumor was limited to the uterus but did not extend beyond. The patient underwent surgical treatment, and the histopathological examination of the resected uterine and splenic specimens disclosed invasive uterine clear cell carcinoma and sclerosing angiomatoid nodular transformation of the spleen, respectively. The patient had no signs of the disease 17 months after surgical treatment.

Conclusions

Sclerosing angiomatoid nodular transformation of the spleen is a very rare benign disease with a misleading presentation when associated with a malignant tumor. Pathological assessment of the resected spleen is the only way to achieve the correct diagnosis.

Sclerosing Angiomatoid Nodular Transformation: Laparoscopic Splenectomy as Therapeutic and Diagnostic Approach at the Same Time

Introduction

Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare benign vascular lesion with unknown etiopathogenesis and with definite features of imaging, histopathology, and immunohistochemistry. It was first described by Martel et al. in 2004, and to date, only 151 cases have been reported.

Case Description

We report a case of SANT of the spleen detected in a 66-year-old Caucasian, without comorbidities, presented to our department with epigastric pain. We, also, presented a review of the literature.

Conclusions

SANT is a benign incidentally vascular condition in the majority of cases. The wide age and gender distribution in our review is in accordance with that in previous studies in English literature. In our opinion, splenectomy is the choice treatment because it is at the same time diagnostic and therapeutic in a definitive way.

A case of sclerosing angiomatoid nodular transformation of the spleen with increased accumulation of fluorodeoxyglucose after 5-year follow-up

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Although sclerosing angiomatoid nodular transformation (SANT) of the spleen is a new entity defined as a benign pathologic lesion, it is very difficult for ruling out the malignancy in preoperative imaging studies.

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Even when accumulation of fluorodeoxyglucose increased slightly during the follow-up period and suggested the possibility of malignant diseases, it is necessary to make a diagnosis of splenic SANT comprehensively.

Introduction

Sclerosing angiomatoid nodular transformation (SANT) of spleen is a new entity defined as a benign pathologic lesion. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) shows weak accumulation, thereby ruling out the malignancy in preoperative diagnosis is difficult. Herein, we reported a case of shrinking SANT with increased FDG accumulation during a 5-year follow-up period, which was treated by laparoscopic splenectomy.

Presentation of case

A 64-year-old female had been referred to our hospital for the evaluation of a splenic tumor. Initial contrast-enhanced computed tomography (CT) showed a well-defined, and ovoid hypoattenuating lesion, measuring 52 mm in diameter in the spleen. Initial PET/CT revealed accumulation of FDG in the tumor (maximum standardized uptake value [SUVmax]: 2.8). The mass was diagnosed as SANT, and the patient was followed-up every 6–12 months for 5 years. Follow-up PET/CT revealed increased accumulation of FDG (SUVmax: 3.5). As it was suspicious considering the differential diagnosis, including malignant lymphoma and inflammatory pseudotumor, she underwent laparoscopic splenectomy. The pathological results showed three types of vessels including capillaries, ectatic small veins, and sinusoids-like vessels, consistent with the features of SANT.

Discussion

A SANT may have features that resemble those of malignancy, including the growing mass and the increase of FDG accumulation.

Conclusion

Although the preoperative diagnosis of SANT is difficult, it is necessary to make a diagnosis of SANT comprehensively, even when accumulation of FDG increased slightly during the follow-up period and suggested the possibility of malignant diseases.