The CT and F-FDG PET/CT appearance of primary renal malignant fibrous histiocytoma

Long-term disease-free survival of an undifferentiated pleomorphic sarcoma of the spleen: A case report and literature review

INTRODUCTION

Undifferentiated pleomorphic sarcoma (UPS) primarily occurs in the soft tissues of the extremities, trunk, and retroperitoneum. As the primary UPS of the spleen (splenic UPS) is extremely rare, to the best of our knowledge, only 19 cases have been reported in English literature. No cases of long-term survival without a local or distant recurrence have been reported.

PATIENT CONCERNS

We report the case of a 37-year-old man who was referred to our hospital for a splenic tumor. He had no past medical or relevant familial history. On abdominal computed tomography (CT), a low attenuation solid mass and cystic component with mural calcifications were present at the lower pole of his spleen. The fluorodeoxyglucose-positron emission tomography (CT) indicated it as malignant tumor of the spleen.

DIAGNOSES

The patient's provisional diagnosis was deduced to be angiosarcoma, which was the most common malignant tumor of the spleen.

INTERVENTIONS

An elective laparoscopic splenectomy was performed, and the histology of the tumor was consistent with UPS (pT1, pN0, cM0, and AJCC8th). No adjuvant therapy was administered.

OUTCOMES

Ten years have passed since the patient's splenectomy, and he continues to do well, without evidence of local or distant recurrence.

LESSONS

To the best of our knowledge, this is the first case of long-term recurrence-free survival after surgical management of a splenic UPS. It is probable that radical splenectomy during the disease played the most important role in the patient's long-term survival. Understanding the characteristic findings of a splenic UPS in an abdominal CT may help to diagnose properly.

PET in the Diagnostic Management of Soft Tissue Sarcomas of Musculoskeletal Origin

Soft tissue sarcomas (STSs) account for less than 1% of adult solid tumors and about 7% of pediatric malignancies, causing 2% of cancer-related deaths. With the advent of PET-computed tomography (CT), the value of (18) fluorine-2-fluoro-2-deoxy-d-glucose (FDG) PET imaging to improve the management of STSs has been explored. FDG PET imaging has been found useful in restaging and treatment response assessment. This article reviews current knowledge and application of FDG PET-CT in initial diagnosis, staging, restaging, treatment response monitoring, and prognosis, with a brief overview of the most common histologic subtypes of STS.

Pleomorphic spindle cell sarcoma (PSCS) (formerly known as malignant fibrous histiocytoma, MFH) of the spleen, mimics an atypical haemangioma on 99mTc-RBC, CT and Ultrasound: staging with 18F-FDG PET/CT

A 63-year-old male was found to have a 7.5-cm splenic mass that had imaging appearances of an atypical haemangioma on CT, ultrasound and a ^99mTc-RBC scan, and he was followed conservatively with serial ultrasounds. Sixteen months later, however, the splenic lesion grew and he developed numerous new liver masses which were biopsy confirmed to be a pleomorphic spindle cell sarcoma (PSCS), formerly known as malignant fibrous histiocytoma (MFH). A staging ¹⁸F-FDG PET/CT was performed and showed innumerable, mostly necrotic hepatic and splenic masses. The patient passed away a few days after the PET/CT, before a treatment program could be implemented. The use of ¹⁸F-FDG PET/CT in the staging of splenic PSCS has not been previously described. We present the ^99mTc-RBC and ¹⁸F-FDG PET/CT image characteristics of a patient with splenic PSCS.

Metastatic Malignant Fibrous Histiocytoma in the Stomach: Imaging With 18F-FDG PET/CT

Metastatic malignant fibrous histiocytoma (MFH) in the stomach is extremely rare. We report a 73-year-old man with MFH in the left popliteal fossa that metastasized to the stomach. Whole-body F-FDG PET/CT showed abnormal tracer uptakes in the stomach, which was subsequently confirmed as metastatic MFH.

Value of FDG PET/CT in Patient Management and Outcome of Skeletal and Soft Tissue Sarcomas

Fluorodeoxyglucose (FDG)-PET/computed tomography (CT) has been increasingly used in bone and soft tissue sarcomas and provides advantages in the initial tumor staging, tumor grading, therapy assessment, and recurrence detection. FDG-PET/CT metabolic parameters are reliable predictors of survival in sarcomas and could be implemented in risk stratification models along with other prognostic factors in these patients.

Molecular imaging of urogenital diseases

There is an expanding and exciting repertoire of PET imaging radiotracers for urogenital diseases, particularly in prostate cancer, renal cell cancer, and renal function. Prostate cancer is the most commonly diagnosed cancer in men. With growing therapeutic options for the treatment of metastatic and advanced prostate cancer, improved functional imaging of prostate cancer beyond the limitations of conventional CT and bone scan is becoming increasingly important for both clinical management and drug development. PET radiotracers, apart from ¹⁸F-FDG, for prostate cancer are ¹⁸F-sodium fluoride, ¹¹C-choline, and ¹⁸F-fluorocholine, and (¹¹C-acetate. Other emerging and promising PET radiotracers include a synthetic l-leucine amino acid analogue (anti-¹⁸F-fluorocyclobutane-1-carboxylic acid), dihydrotestosterone analogue (¹⁸F-fluoro-5α-dihydrotestosterone), and prostate-specific membrane antigen-based PET radiotracers (eg, N-[N-[(S)-1,3-dicarboxypropyl]carbamoyl]-4-¹⁸F-fluorobenzyl-l-cysteine, ⁸⁹Zr-DFO-J591, and ⁶⁸Ga [HBED-CC]). Larger prospective and comparison trials of these PET radiotracers are needed to establish the role of PET/CT in prostate cancer. Although renal cell cancer imaging with FDG-PET/CT is available, it can be limited, especially for detection of the primary tumor. Improved renal cell cancer detection with carbonic anhydrase IX (CAIX)-based antibody (¹²⁴I-girentuximab) and radioimmunotherapy targeting with ¹⁷⁷Lu-cG250 appear promising. Evaluation of renal injury by imaging renal perfusion and function with novel PET radiotracers include p-¹⁸F-fluorohippurate, hippurate m-cyano-p-¹⁸F-fluorohippurate, and rubidium-82 chloride (typically used for myocardial perfusion imaging). Renal receptor imaging of the renal renin-angiotensin system with a variety of selective PET radioligands is also becoming available for clinical translation.

A therapeutic strategy for metastatic malignant fibrous histiocytoma through mesenchymal stromal cell-mediated TRAIL production

OBJECTIVE

To overcome the therapeutic limitations of malignant fibrous histiocytoma (MFH), we evaluated human adipose tissue-derived mesenchymal stromal cells (MSCs) that secrete tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on metastatic MFH.

BACKGROUND

MFH is a highly malignant and metastatic type of sarcoma but surgical removal is the only effective method for treating MFH. MSCs are easily transduced to express a high level of transgene and can migrate toward cancer. For this reason, MSCs are a promising candidate for metastatic MFH therapies.

METHODS

In vitro sustainability of MSC-TRAIL against MFH-ino was analyzed by apoptosis assay. For preclinical study, anti-MFH effects of MSC-TRAILs were validated in murine models for local tumorigenesis and metastasis. Furthermore, a time-interval metastasis model of MFH was applied to confirm antimetastatic ability of MSC-TRAIL for preestablished metastatic MFH.

RESULTS

We found that MFH-ino is highly susceptible to recombinant TRAIL and MSC-TRAIL, which selectively induce apoptosis via caspase-8 activation in vitro. Moreover, not only MFH-ino but xenograft explants were also significantly inhibited by MSC-TRAIL in local tumorigenesis. In particular, the metastatic ability of MFH-ino was considerably reduced by MSC-TRAIL in metastasis murine model, particularly for preestablished metastatic MFH.

CONCLUSIONS

These results suggest that MSC-TRAIL is sufficiently effective in inhibiting MFH-ino metastasis and the application using MSC-TRAIL could be extended to other sarcomas and recurrent metastatic cancers for cell-mediated cancer therapy.

¹⁸F-FDG-PET/CT findings of retroperitoneal tumors: a pictorial essay

A variety of different tumors can arise from any of the tissues present in the retroperitoneum, and they exhibit a wide range of pathologic types. Although computed tomography (CT) and magnetic resonance imaging (MRI) can demonstrate important characteristics of these tumors, diagnosis is often challenging for radiologists. The purpose of this pictorial essay is to review (18)F-fluorodeoxyglucose positron emission tomography/CT (FDG-PET/CT) features of different kinds of benign and malignant retroperitoneal tumors in comparison with CT or MRI findings alone and to become familiar with the wide variety of imaging characteristics.

Primary Malignant Fibrous Histiocytoma in Mediastinum: Imaging with (18)F-FDG PET/CT

Malignant fibrous histiocytoma (MFH) is the most common soft tissue tumor which often occurs in the extremities and the retroperitoneum. Primary mediastinal MFH is rare; thus, findings on (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) of mediastinal MFH have not been reported yet. We report herein the case of a 64-year-old man who was presented with a superior mediastinal mass. The mass showed intense (18)F-FDG uptake with central metabolic defect on PET/CT. The maximum standardized uptake value was 17.4. After tumor removal via median sternotomy, an MFH of the storiform-pleomorphic type was diagnosed on histopathologic examination. We present the first report of (18)F-FDG PET/CT imaging of MFH in the superior mediastinum.

Conservative treatment of malignant fibrous histiocytoma of the kidney: a case report

Primary renal malignant fibrous histiocytoma is an extremely rare disease. There are neither clinical nor radiological signs to distinguish it from the most common renal cell carcinoma. Its prognosis is poor because of its tendency to locally recur and metastasize. Therefore, early diagnosis and proper treatment are very important. We present the case of a 66-year-old woman diagnosed with primary renal malignant fibrous histiocytoma who underwent partial nephrectomy. After 41 months' follow-up, there was no evidence of any recurrence. To our knowledge, this is the first reported case of conservative surgery for this kind of tumor.