Enhanced CT and FDG PET/CT findings of splenic hamartoma

FDG PET/CT in Papillary Intralymphatic Angioendothelioma of the Spleen

ABSTRACT

Splenic papillary intralymphatic angioendothelioma is extremely rare. We describe FDG PET/CT and MRI findings of splenic papillary intralymphatic angioendothelioma in a young adult. The splenic tumor showed hypodensity and increased FDG uptake with SUV max of 4 on PET/CT, heterogeneous signal intensity with internal hypointense stellate scars on T2-weighted image, and progressive centripetal enhancement on dynamic contrast-enhanced T1-weighted images. This case indicates that papillary intralymphatic angioendothelioma should be included in the differential diagnosis of FDG-avid splenic lesions.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: A Diagnostic Conundrum

A splenic lesion often represents a diagnostic challenge due to relative scarcity and the broad differential diagnosis. Sclerosing Angiomatoid Nodular Transformation (SANT) of the spleen is usually encountered only incidentally. Although benign, patients with SANT often receive splenectomy, due to its rarity, diagnostic uncertainty and sometimes intimidating imaging morphology and size. Imaging features on computed tomography, magnetic resonance and positron emission tomography have a high diagnostic value for SANT and help differentiate this entity from other splenic lesions. When the imaging parameters are matched with core needle biopsy tissue analysis, further watchful waiting can be recommended in order to avoid splenectomy.

FDG PET/CT Image of a Solitary Rib Hamartoma

ABSTRACT

Hamartoma of the rib is very rare in adults. Herein, we report a 49-year-old woman who complained of chest pain for 1 month. FDG PET/CT revealed focal osteolytic bone destruction in the right 11th rib with elevated FDG uptake. The postoperative pathology supported the diagnosis of hamartoma. Our case shows that hamartoma should be considered as a differential diagnosis when there is solitary osteolytic bone destruction in the rib with intense FDG uptake.

Incidentally discovered asymptomatic splenic hamartoma misdiagnosed as an aneurysm: A case report

BACKGROUND

Splenic hamartoma (SH) is a rare, benign vascular proliferation that is often found incidentally. It may be misdiagnosed as a splenic aneurysm or splenic malignancy.

CASE SUMMARY

A 21-year-old male patient was admitted to our hospital with a complaint of an incidentally discovered asymptomatic splenic space-occupying lesion for 2 wk. Abdominal computed tomography (CT) scan showed a circular low-density shadow in the hilum of the spleen. Contrast-enhanced CT revealed an aneurysm located in the hilum of the spleen before operation. Laparoscopic splenectomy was performed and postoperative pathology revealed the presence of SH.

CONCLUSION

Imaging studies are insufficient for the differential diagnosis of SH from other diseases, and laparoscopic splenectomy is a less invasive procedure and useful for the diagnostic purpose as well.

FDG PET/CT Findings in a Localized Reactive Lymphoid Hyperplasia of the Spleen

A 38-year-old man with sigmoid colon cancer underwent a preoperative contrast-enhanced CT which incidentally revealed a modestly enhancing splenic mass. FDG PET/CT showed mildly increased uptake in the splenic lesion in contrast to prominently increased uptake in the colonic tumor. In addition, the splenic mass demonstrated only slightly increased signal intensity in diffusion-weighted MRI, suggesting low probability of metastasis. Splenectomy nonetheless was performed at surgery of the colon cancer. The histopathologic examination showed aggregated lymphoid follicles with germinal centers in the splenic lesion and made the diagnosis of localized reactive lymphoid hyperplasia a rare benign lymphoid tumor.

Evidence-based management of incidental focal uptake of fluorodeoxyglucose on PET-CT

Focal incidental uptake, with or without CT abnormalities, is a common finding on fluorodeoxyglucose PET/CT and evidence-based management for this type of uptake is lacking. This article reviews the evidence on focal incidental uptake including the incidence of malignancy, differential diagnosis and imaging criteria which can be used to further characterize it. The article focusses on PET rather than CT criteria. The strength of the evidence base is highly variable ranging from systematic reviews and meta-analyses to a virtual absence of evidence. Caution needs to be used when using standardized uptake values (SUVs) reported in other studies due to interpatient and institution observed variation in SUVs. There is sufficient evidence to permit specific suggestions on how to interpret the foci and recommend further management in the: pituitary (investigate when SUVmax >4.1), thyroid (investigate all), breast (investigate all), lung parenchyma (if focus of fluorodeoxyglucose without a CT nodule, no further investigations), colon (investigate all foci with SUVmax >5.9, urgently if SUVmax >11.4), adrenals (criteria depend on if patient has cancer) and prostate gland (investigate in males aged >50 years or >40 years if peripheral uptake or patient has other risk factors). There is some evidence to guide further management for the parotid gland, naso-orophaynx, oesophagus, pancreas, uterus and ovaries. There is insufficient evidence to guide management for the liver, spleen, kidneys, gallbladder, testis and bone, for these organs patient characteristics and other guidelines will likely be of more use in determining further management.

Evaluation of Spleen Glucose Metabolism Using 18F-FDG PET/CT in Patients with Febrile Autoimmune Disease

The purpose of this study was to evaluate the clinical significance of ¹⁸F-FDG uptake by the spleen in patients with autoimmune disease. Methods: We retrospectively reviewed Severance Hospital's electronic medical records of patients hospitalized for the evaluation of fever who underwent ¹⁸F-FDG PET/CT. We found 91 patients with autoimmune diseases and 101 patients with localized infection. ¹⁸F-FDG uptake was assessed by measuring SUV in the spleen and liver. The spleen-to-liver ratio of the SUV_mean (SLR_mean) was calculated. Clinical and laboratory parameters were collected and evaluated for association with SLR_mean In-hospital mortality was defined as all-cause mortality during hospital admission for fever. Results: SLR_mean was significantly higher in autoimmune disease than in localized infectious disease (1.28 ± 0.43 vs. 0.91 ± 0.21, P < 0.001). In autoimmune disease, SLR_mean was correlated with monocytes, aspartate aminotransferase, alanine aminotransferase, albumin, and ferritin. Analysis of receiver-operating-characteristic curves revealed that in comparison with laboratory parameters, SLR_mean had the highest performance in differentiating autoimmune from localized infectious disease. Multivariate logistic regression analysis demonstrated that high SLR_mean and low platelets were significantly associated with in-hospital mortality in febrile autoimmune disease. Conclusion: These findings suggest that spleen glucose metabolism is increased in febrile autoimmune disease. Spleen ¹⁸F-FDG uptake may provide information useful in differentiating febrile autoimmune disease from localized infectious disease and predicting clinical outcomes in febrile autoimmune disease.

FDG PET/CT Findings in Multiple Splenic Amebomas (Amebic Granulomas)

Splenic ameboma (amebic granuloma) is rare. A 38-year-old man with a severe pneumonia due to inhalation of swimming pool water 18 months ago complained of night sweat, tiredness, and anorexia for 1 month. Abdominal ultrasound showed multiple nodules in the spleen. These nodules showed slight enhancement on enhanced CT and intense FDG uptake on PET/CT. Splenectomy was performed. Multiple splenic amebomas were confirmed by pathology. Free-living amoebae were also detected in samples of pleural effusion and blood. Splenic ameboma, although rare, should be included in the differential diagnosis with isolated focally increased FDG activity in the spleen.