Extramedullary Plasmacytoma of the Gallbladder Detected on Fluorine 18-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Incidentally Detected Extramedullary Plasmacytoma of the Gallbladder: A Case Report and Literature Review

Extramedullary plasmacytoma (EMP) can rarely occur in conjunction with multiple myeloma (MM). EMPs are usually detected in the upper aerodigestive tract (UAD) but can also occur along the digestive tract. However, the involvement of gallbladder is uncommon. Gastrointestinal tract symptoms often lead to the diagnosis of EMP in the gallbladder. An 81-year-old man was referred to our hospital with suspected primary gallbladder carcinoma. He was subsequently operated on, and the pathological findings showed EMP of the gallbladder without MM.

Malignant Lymphoma Diagnosed as Gallbladder Carcinoma on 18F-FDG PET/CT

ABSTRACT

Extranodal primary lymphoma of gallbladder is extremely rare. We report a 48-year-old woman initially diagnosed as gallbladder carcinoma with lymph nodes metastases by contrast-enhanced CT and MRI. Meanwhile the images of 18F-FDG PET/CT highly suggested gallbladder carcinoma due to the necrosis in one of the enlarged lymph nodes. However, it was proved to be diffuse large B-cell lymphoma by the histopathological diagnosis.

Secondary Extramedullary Myeloma of the Gallbladder: A Case Report

Extramedullary myeloma (EMM) is an infrequent but well-established manifestation of multiple myeloma (MM), defined as a soft tissue plasma cell neoplasm without bone marrow involvement. Gallbladder involvement in EMM, however, is a very rare occurrence, with only 8 cases found in the English medical literature. Here, we present a case of an older adult male with a gallbladder mass in the presence of increasing serum kappa light chains after a normal bone marrow biopsy confirmed the complete remission of a previous MM diagnosis. Histopathologic evaluation of a biopsied sample confirmed the mass as an atypical plasma cell neoplasm. Later in his treatment, he developed several firm, smooth, violaceous skin nodules on the torso, which histopathology confirmed as also being atypical plasma cell neoplasms. We aim to contribute to the medical literature by expanding the pool of information regarding EMM of the gallbladder to support future diagnostic and treatment recommendations.

PET/CT Variants and Pitfalls in Liver, Biliary Tract, Gallbladder and Pancreas

A wide variety of pathological anomalies may occur in the liver, biliary system, and pancreas. It is a necessity to use many different imaging techniques in order to distinguish such varied pathologies, especially those from malignant processes. Positron Emission Tomography/Computed Tomography (PET/CT) is an imaging method that has proven its diagnostic value in oncology and can be used for different clinical purposes. Fluoro-18 fluoro-2-deoxy-D-glucose has a wide range of uses as a dominant radiopharmaceutical in routine molecular imaging, however, molecular imaging has started to play a more important role in personalized cancer treatment in recent years with new Fluoro-18 and Gallium-68 labeled tracers. Although molecular imaging has a strong diagnostic effect, the surprises and pitfalls of molecular imaging can lead us to unexpected and misleading results. Prior to PET/CT analysis and reporting, information about possible technical and physiological pitfalls, normal histological features of tissues, inflammatory pathologies, specific clinical features of the case, treatment-related complications and past treatments should be evaluated in advance to avoid misinterpretation. In this review, the physiological and pathophysiological variants as well as pitfalls encountered in PET/CT imaging of the liver, biliary tract, gallbladder, and pancreas will be examined. Other benign and malignant pathologies that have been reported to date and that have led to incorrect evaluation will be listed. It is expected that the devices, software, and artificial intelligence applications that will be developed in the near future will enable much more effective and faster imaging that will reduce the potential causes of error. However, as a result of the dynamic and evolving structure of the information obtained by molecular imaging, the inclusion of the newly developed radiopharmaceuticals in routine practice will continue to carry new potentials as well as new troubles. Although molecular imaging will be the flagship of diagnostic oncology in the 21st century, the correct analysis and interpretation by the physician will continue to form the basis of achieving optimal performance.

The role of initial 18F-FDG PET/CT in the management of patients with suspected extramedullary plasmocytoma

Background

Extramedullary plasmacytoma (EMP) is a plasma cell malignancy that originates in soft tissues without evidence of systemic spread, and its management differs from other plasma cell neoplasms. The purpose of the present study was to evaluate the role of initial ¹⁸F-FDG PET/CT in the management of patients with clinical suspected EMP.

Methods

¹⁸F-FDG PET/CT scans performed in 21 patients (M/F = 12/9, mean age 51.1 ± 15.3 years) with clear suspicion of EMP from 2006 to 2015 were analysed retrospectively. The detection of new lesions and the change in treatment were evaluated.

Results

PET/CT detected new lesions in 38.1% (8/21) of patients with 17 lesions, and lymph nodes were the most common site, accounting for 70.6% (12/17) of all lesions, followed by bone (n = 2), and less frequently, breast (n = 1), lung (n = 1), and stomach (n = 1). These findings resulted in treatment changes in 7 patients with EMP. Among these, 4 patients had major treatment changes and 3 patients had minor changes. Of the 21 patients, progression to MM was observed in 8 patients (8/21, 38.1%). In univariate analysis, tumour size > 4 cm and partial response (PR) after treatment were significant prognostic factors for Progression-free survival (PFS).

Conclusions

Our data indicated that ¹⁸F-FDG PET/CT is helpful in the detection of additional lesions throughout the body, including lymph node involvement and distant additional lesion, which may have resulted in treatment change.

Multiple Extramedullary Plasmacytoma in a Setting of Complete Bone Marrow Remission: Food for Thought

Extramedullary plasmacytoma as a mode of relapse in multiple myeloma (MM) is unusual. Current recommendations do not incorporate the routine use of 18-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET/CT) imaging prior to haematopoietic stem cell transplant (HSCT) in MM. We report a case of relapsed MM with complete remission as per IMWG criteria. In the interim period, before the HSCT, the patient had localizing neurological signs and symptoms attributed to multiple extramedullary plasmacytomas. The uniqueness of this case is that this patient after complete marrow remission with no obvious external masses had unexpected, symptomatic multiple extramedullary plasmacytomas. This case illustrates the need for integration of FDG PET/CT imaging into routine pre-HSCT investigations in relapsed MM to prevent missing any asymptomatic extramedullary plasmacytomas.