Cervical tuberculous lymphadenitis mimicking distant lymph node metastasis on F-18 FDG PET/CT in a patient with gastric carcinoid tumor

Tuberculous Lymphadenitis in a Patient Receiving PD-1 Inhibitor for Melanoma: A Case Report and Brief Literature Review

Oncolytic immunotherapy is a novel and promising approach in clinical oncology practice. Currently, immune checkpoint inhibitors (ICIs) are the first-line treatment options for disseminated melanoma. Nivolumab is a well-defined ICI that blocks programmed cell death 1 (PD-1) and mainly increases anti-tumor immunity. The opportunistic infections are not expected with ICI therapies due to their immune reactivation effects. To date, only a few cancer patients have been reported with activated TB during ICI therapy. Here, we presented a young female patient diagnosed with histologically-confirmed tuberculous lymphadenitis while on nivolumab therapy for metastatic melanoma. The current case report represents the first described tuberculous lymphadenitis case related to anti-PD-1 based monoclonal antibody therapy. The mechanism underlying the development of TB with PD-1 inhibitor use has not been illuminated yet. Triggering of excessive inflammatory responses with ICIs therapy is a potential cause. Considering the increased utilization of ICI-based immunotherapies, the TB screening should be considered in all patients before starting PD-1 inhibitor therapy.

[Tuberculous lesion of retropharyngeal lymph nodes responsible for labored nasal breathing]

A 62 year-old patient applied for the medical aid with complaints of labored nasal breathing. She was treated for tuberculosis in the childhood, underwent radical mastectomy in connection with left breast cancer in 2007 and adenotomy at the age of 60 years with the good functional outcome. One year after adenotomy, the enlargement of lymph nodes at the left-hand antero-lateral surface of the neck was detected. The histological changes in the lymph nodes corresponded to the picture of tuberculosis. Pharyngoscopy demonstrated an asymmetric protrusion at the posterior wall of the pharynx more prominent on the left side. Examination by spiral computed tomography revealed the presence of two enlarged lymph nodes with the signs of suppurative melting in the retropharyngeal space. These lymph nodes were opened through the posterior pharyngeal wall which resulted in the restoration of the normal pharynx configuration and the normalization of nasal breathing.

Potential role of (18)F-2-fluoro-2-deoxy-glucose positron emission tomography/computed tomography imaging in patients presenting with generalized lymphadenopathy

Generalized lymphadenopathy is a common and often vexing clinical problem caused by various inflammatory, infective and malignant diseases. We aimed to review briefly and highlight the potential role of (18)F-2-fluoro-2-deoxy-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT) in such patients. (18)F-FDG PET/CT can play an important role in the management of generalized lymphadenopathy. It can help in making an etiological diagnosis; can detect extranodal sites of involvement and employed for monitoring response to therapy.

Extensive tuberculous lymphadenitis mimicking distant lymph node metastasis on F-18FDG PET/CT in a patient with a history of malignant melanoma

18-Fluoredeoxyglucose position emission tomography and computed tomography (F-18FDG PET/CT) scanning has been useful in the evaluation of malignant disorders and has been extensively used in cancer screening. However, F-18FDG uptake was not found to be specific for cancer diagnosis. Here, we describe increased F-18FDG uptake on PET/CT caused by extensive tuberculous lymphadenitis in a 62-year-old woman with malignant melanoma.

Ascites metabolism measurement enhanced the diagnostic value and accuracy of prognostic evaluation in 18F-FDG PET/CT studies in malignant ascites patients

OBJECTIVE

This study aimed to evaluate the role of ascites metabolism measurement in (18)F-fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (CT) for auxiliary diagnosis and prognostic evaluation of malignant ascites.

MATERIALS AND METHODS

This was a retrospective study on 55 patients, including 36 with malignant ascites and 19 with benign ascites of undetermined origin, before they underwent their first (18)F-FDG PET/CT scan. The χ(2) -test was used to compare the diagnostic efficiencies among (18)F-FDG PET/CT ascites metabolism measurement, tumor localization, and ascites cytology examination. The standard uptake values of ascites and of the normal liver were measured, respectively, and their ratio, denoted as T/NT, was calculated for each patient. The receiver-operating characteristic curve was used to analyze the diagnostic efficiency of the ascites T/NT, ascites carcinoembryonic antigen, ascites CA1(25), and ascites CA(199), and the linear regression was used to analyze the relationship between the ascites T/NT and the survival time of patients.

RESULTS

The metabolic level of malignant ascites was high. The sensitivity and accuracy of ascites metabolism measurement were higher than those of ascites cytology examination (χ(2) =6.98, 4.58; all P's<0.05). The specificity of ascites metabolism measurement was higher than that of (18)F-FDG PET/CT tumor localization (χ(2) =5.70, P<0.05). The T/NT value of malignant ascites (0.68 ± 0.17) was higher than that of benign ascites (0.38 ± 0.10) (t=7.21, P<0.05). The area under the receiver-operating characteristic curve of ascites T/NT was larger than those of ascites carcinoembryonic antigen, CA(125), and CA(199). There was a negative correlation between the ascites T/NT and the survival of patients with malignant ascites (r=-0.647, P<0.01).

CONCLUSION

Ascites metabolism measurement has an important auxiliary diagnostic value in (18)F-FDG PET/CT for ascites patients. The ascites T/NT may be a good index for prognostic evaluation of malignant ascites.

Usefulness of F-18 FDG PET/CT in the evaluation of neck swelling in polymorphic posttransplant lymphoproliferative disorder after renal transplantation

A 38-year-old man with a history of renal transplantation presented with a 3-month history of bilateral neck swelling. Ultrasonography of the neck showed multiple enlarged lymph nodes at the bilateral neck. Histologic examination of a specimen from an excisional biopsy at right level II cervical lymph node revealed polymorphic posttransplant lymphoproliferative disorder. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography scan was performed for further evaluation. The scan revealed marked enlargement and intense hypermetabolism of the lymph nodes along the bilateral cervical lymph node chains (Fig. 1). Several reports have described that diverse infectious or inflammatory disorders and malignant diseases show various degree of FDG uptake of cervical lymph nodes. This case illustrates that the possibility of posttransplant lymphoproliferative disorder should be considered in renal transplant patients with increased FDG uptake of cervical lymph nodes on F-18 FDG positron emission tomography/computed tomography scan.