68Ga-DOTATOC PET/CT in Pleural Solitary Fibrous Tumors

Effective management of recurrent Doege-Potter syndrome with somatostatin-analogues: A case report

BACKGROUND

Doege-Potter syndrome is defined as paraneoplastic hypoinsulinemic hypoglycemia associated with a benign or malignant solitary fibrous tumor frequently located in pleural, but also extrapleural sites. Hypoglycemia can be attributed to paraneoplastic secretion of "Big-IGF-II," a precursor of Insulin-like growth factor-II. This prohormone aberrantly binds to and activates insulin receptors, with consecutive initiation of common insulin actions such as inhibition of gluconeogenesis, activation of glycolysis and stimulation of cellular glucose uptake culminating in recurrent tumor-induced hypoglycemic episodes. Complete tumor resection or debulking surgery is considered the most promising treatment for DPS.

CASE

Here, we report a rare case of a recurrent Doege-Poter Syndrome with atypical gelatinous tumor lesions of the lung, pleura and pericardial fat tissue in an 87-year-old woman. Although previously described as ineffective, we propose that adjuvant treatment with Octreotide in conjunction with intravenous glucose helped to maintain tolerable blood glucose levels before tumor resection. The somatostatin-analogue Lanreotide was successfully used after tumor debulking surgery (R2-resection) to maintain adequate blood glucose control.

CONCLUSION

We conclude that somatostatin-analogues bear the potential of being effective in conjunction with limited surgical approaches for the treatment of hypoglycemia in recurrent or non-totally resectable SFT entities underlying DPS.

Surgery for Solitary Fibrous Tumors of the Pleura: A Review of the Available Evidence

Solitary fibrous tumors of the pleura (pSFT) are a relatively rare neoplasms that can arise from either visceral or parietal pleura and may have different aggressive biological behaviors. Surgery is well known to be the cornerstone of the treatment for pSFT. We reviewed the existing literature, focusing on the role of surgery in the management and treatment of pSFT. All English-written literature has been reviewed, focusing on those reporting on the perioperative management and postoperative outcomes. Surgery for pSFT is feasible and safe in all experiences reported in the literature, but surgical approaches and techniques may vary according to the tumor dimensions, localization, and surgeons' skills. Long-term outcomes are good, with a 10-year overall survival rate of more than 70% in most of the reported experiences; on the other hand, recurrence may happen in up to 17% of cases, which occurs mainly in the first two years after surgery, but case reports suggest the need for a longer follow-up to assess the risk of late recurrence. Malignant histology and dimensions are the most recognized risk factors for recurrence. Recurrence might be operated on in select patients. Surgery is the treatment of choice in pSFT, but a radical resection and a careful postoperative follow-up should be carried out.

Ga68-FAPI Imaging and Lu177-FAPI Therapy in a Case of Metastatic Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) of the central nervous system (previously called hemangiopericytoma) is a rare mesenchymal tumor. Malignant SFT has a tendency to recur after surgery and can metastasize to distant organs. Treatment options for metastatic disease are limited. This case demonstrated high expression of FAP (fibroblast activating protein) in all metastatic sites with Ga-FAPI positron emission tomography-computed tomography imaging. Subsequently, the patient was treated with Lu177-FAPI-targeted radionuclide therapy. There was significant clinical response. There was mild partial morphological response seen on follow-up imaging.

68 Ga-DOTATOC PET/CT Imaging of a Muscular Solitary Fibrous Tumor

ABSTRACT

A 73-year-old woman was referred for 68 Ga-DOTATOC PET/CT staging of a grade 2 pancreatic neuroendocrine tumor, which showed the primary pancreatic tumor, liver metastases, one left pleural metastasis, and high uptake in a mass of the right triceps brachii muscle. Two years before, she underwent 18 F-FDG PET/CT and 111 In-pentetreotide scan, respectively, with low and high uptake of each radiotracer in the triceps mass. Histopathological analysis revealed a solitary fibrous tumor. Immunohistochemistry showed no staining for SSTR-2 and SSTR-5, suggesting tumor overexpression of another somatostatin receptor. This case highlighted a potential pitfall on 68 Ga-DOTATOC PET/CT.

Abdominopelvic Hemangiopericytoma Mimicking Neuroendocrine Tumor on 68 Ga-DOTANOC PET/CT

ABSTRACT

We present the case of a 60-year-old man who was being evaluated for 2 intra-abdominal masses. The masses were tracer avid on 68 Ga-DOTANOC PET/CT and were suggestive of neuroendocrine tumor. Histopathology, however, confirmed the masses to be hemangiopericytoma. Hemangiopericytoma comes under the umbrella of solitary fibrous tumors, a rare tumor group arising from the mesenchymal cells. Solitary fibrous tumors commonly arise from the pleura but can occur anywhere in the body. Intra-abdominal hemangiopericytoma are extremely rare and should be kept in mind as one of the differential diagnoses for 68 Ga-DOTA peptide-avid tumors.

68 Ga-PSMA-Avid Intranasal Solitary Fibrous Tumor

ABSTRACT

The utility of molecular imaging in solitary fibrous tumors has not been fully established. We present a rare case of recurrent intranasal solitary fibrous tumor incidentally localized on 68 Ga-PSMA PET/CT scan, which turned out to be metabolically inactive on 18 F-FDG PET/CT.

A Rare Case of Solitary Fibrous Tumor of Maxilla: Findings on F-18 FDG and Ga-68 DOTANOC PET-CT

Solitary fibrous tumor (SFT) is a rare tumor of mesenchymal origin that most commonly involves the pleura but can be found anywhere in the body. SFT can range from indolent benign tumors to aggressive malignant tumors, and pre-operative diagnosis is based mainly on imaging. In this case report, we describe an extremely rare case of SFT of left maxilla on F-18 FDG PET-CT and Ga-68 DOTANOC PET-CT. Very few cases of PET-CT findings in SFT are reported in literature; and to our knowledge, none involving the maxilla. By highlighting the findings on F-18 FDG and GA-68 DOTANOC PET-CT, we aim to further add on to the role of both the tracers in the diagnosis and management of this tumor group.