Follicular dendritic cell sarcoma of the mediastinum: CT and 18 F-fluoro-2-deoxyglucose PET findings

FDG PET/CT in Follicular Dendritic Cell Sarcoma of the Jejunum With Hepatic Metastasis

ABSTRACT

Follicular dendritic cell sarcoma of the gastrointestinal tract is a rare malignancy. We describe contrast-enhanced CT and FDG PET/CT findings in a case of jejunal follicular dendritic cell sarcoma with hepatic metastasis. The primary jejunal tumor showed inhomogeneous enhancement on contrast-enhanced CT and intense FDG uptake on PET/CT mimicking adenocarcinoma or gastrointestinal stromal tumor. The hepatic metastatic tumor showed hypovascularity on contrast-enhanced CT and mild FDG uptake on PET/CT. This case indicates that follicular dendritic cell sarcoma should be included in the differential diagnosis of the hypermetabolic intestinal lesions.

Not always 'squame': The rare entity of follicular dendritic cell sarcoma of the tonsil presenting with cervical nodal metastases

Although squamous cell carcinoma accounts for the overwhelming majority of head and neck malignant neoplasms, extranodal follicular dendritic cell sarcoma (FDCS) of the pharyngeal region can have a similar clinical presentation. The histopathological features of this rare entity have been described and emphasised in the literature. We present the case of a 65-year-old male patient with FDCS of the tonsil to illustrate the radiologic findings of FDCS and also highlight this infrequent but salient differential diagnosis for adult head and neck neoplasia.

18F-FDG PET/CT in Follicular Dendritic Cell Sarcoma With Paraneoplastic Pemphigus as the First Manifestation

A 48-year-old woman presented with refractory oral ulcers and skin rashes on the palms and trunk, diagnosed as paraneoplastic pemphigus. The chest x-ray revealed a mass in the right lower chest, and the F-FDG PET/CT scan showed the lesion in the right anterior-inferior mediastinum with intense F-FDG uptake, accompanied by right parasternal adenopathy and pleural effusion. The surgical pathology proved a follicular dendritic cell sarcoma, with right parasternal lymph node metastasis.

Follicular dendritic cell sarcoma in the right chest wall: A case report

RATIONALE

Follicular dendritic cell sarcoma (FDCS) is a rare malignant tumor that originates from germinal center follicular dendritic cells, and can occur at both nodal and extranodal sites. There are very few described cases of FDCS arising in the chest wall.

PATIENT CONCERNS

A 44-year-old male patient presented with a history of right chest wall pain for 5 months.

DIAGNOSES

Positron emission tomography/computed tomography showed a significant increase in F-fluorodeoxyglucose uptake and multiple small axillary lymph nodes without hypermetabolic lesions. Immunohistochemistry results of a core-needle biopsy indicated FDCS, which was consistent with the postoperative pathological examination.

INTERVENTIONS

The patient underwent tumor resection with lymphadenectomy of level I axillary nodes. No metastasis in the lymph nodes was observed in the postoperative pathological examination. The patient did not accept chemotherapy or radiotherapy.

OUTCOMES

After 18 months, the patient remains in good condition with no evidence of disease recurrence.

LESSONS

This report highlights a rare case of a FDCS arising in the chest wall. Accurate clinical diagnosis and staging of this rare malignant sarcoma is essential for the developmnt of effective treatment strategies. Preoperative F-fluorodeoxyglucose positron emission tomography/computed tomography scanning combined with core-needle biopsy could provide differentiation between benign and malignant tumors, as well as lymph node involvement and metastatic status.

Mediastinal follicular dendritic cell sarcoma: a rare, potentially under-recognized, and often misdiagnosed disease

Background

Mediastinal follicular dendritic cell sarcoma (FDCS) is extremely rare. Due to potential under-recognization of this disease, it happens to be misdiagnosed, especially on core needle biopsy. We report 3 cases of mediastinal FDCS and provide a literature review to improve better understanding of the tumor and to reduce misdiagnosis.

Methods

Three cases of mediastinal FDCS in our clinic practice were studied, including their core needle biopsy and resected specimens, and those cases reported previously in English literature were retrieved and analyzed.

Results

The core needle biopsy of case 1 showed a tumor reminiscent of classical Hodgkin’s lymphoma (CHL), while the resected mass was finally diagnosed with FDCS combined with hyaline-vascular Castleman’s disease. Both the biopsy and resected tissue of case 2 were constitutive of the clear epithelioid cells with marked atypia. In both cases, definitive diagnoses were not made on core needle biopsy. In case 3, there were some areas morphologically similar to CHL, and some areas contained ovoid to spindle-shaped tumor cells with fascicular pattern. The analysis of 43 cases of mediastinal FDCS showed the age of patients were from 16 to 76 years old, the male to female ratio was 1.5:1, the maximal tumor diameters were 3–17 cm. 18 cases were underwent preoperative biopsy, whereas 15 (83.3%) of which were misdiagnosed initially, often as lymphoma. 32 patients had available follow-up data, the rates of recurrence, metastasis, and mortality were 12.5, 18.8 and 28.1%, respectively. Current limited data suggested no statistical differences between adverse prognosis and gender, age, tumor size, necrosis, or different therapeutics, respectively.

Conclusions

Mediastinal FDCS is a rare malignancy that has yet not been fully understood and been often misdiagnosed, particularly when making a diagnosis on core needle biopsy. Increased awareness of this enigmatic tumor is crucial to avoid diagnostic pitfalls.

Follicular dendritic sarcoma masquerading as fibrosing mediastinitis

Fibrosing mediastinitis (FM) is a rare disorder resulting from abnormal immunological-mediated fibro-proliferative reaction in the mediastinum. Here, we describe a case of a 46-year-old female with an incidentally found 11×9 cm posterior mediastinal mass. Multiple biopsies of this unresectable, 18-fluorodeoxyglucose avid mass revealed marked fibrosis without any evidence of malignancy, suggesting idiopathic fibrosing mediastinitis as our initial diagnosis. Multiple interventions including a trial of steroids, fluconazole, and azathioprine to target fibrosing mediastinitis were not successful. Repeat biopsy was consistent with primary mediastinal follicular dendritic cell sarcoma. The manuscript highlights the heightened need for suspecting occult malignancies in cases of FM presenting with an indeterminate cause.

Clinicopathologic characteristics, treatment outcomes, and prognostic factors of primary thoracic soft tissue sarcoma: A multicenter study of the Anatolian Society of Medical Oncology (ASMO)

Background

Soft tissue sarcomas (STSs) are rare malignant tumors of embryogenic mesoderm origin. Primary thoracic STSs account for a small percentage of all STSs and limited published information is available. This study aimed to identify the prognostic factors for thoracic STSs and evaluate the disease's clinical outcomes.

Methods

The medical records of 109 patients with thoracic STSs who were treated between 2003 and 2013 were retrospectively reviewed. Patients' survival rates were analyzed and potential prognostic factors evaluated.

Results

The median follow-up period was 29 months (range: 1–121 months). STSs were most frequently localized on the chest wall (n = 42; 38.5%) and lungs (n = 42; 38.5%). The most common histological types were malignant fibrous histiocytoma (n = 23; 21.1%), liposarcoma (n = 17; 15.6%), and leiomyosarcoma (n = 16; 14.7%). The median survival time of all patients was 40.3 months (95% confidence interval, 14.22–66.37 months), with one and five-year survival rates of 93.4% and 63.5%, respectively. Univariate analysis of all groups revealed that metastatic stage, unresectability, tumor diameter of >10 cm, tumor location other than the chest wall, and grade 3 diseases were predictable of poor survival. However, only grade 3 diseases and tumor location other than the chest wall were confirmed by multivariate analysis as poor prognostic factors.

Conclusions

Primary thoracic STSs are rarely seen malignant tumors. Our results indicated that patients with low-grade tumors and those localized on the chest wall often experienced better survival outcomes.