Mediastinal FDG-positive lymph nodes simulating melanoma progression: drug-induced sarcoidosis like/lymphadenopathy related to ipilimumab

18F-FAPI PET/CT performs better in evaluating mediastinal and hilar lymph nodes in patients with lung cancer: comparison with 18F-FDG PET/CT

BACKGROUND

The aim of this study was to evaluate the efficacy of fluorine 18 (18F) labeled fibroblast activation protein inhibitor (FAPI) in identifying mediastinal and hilar lymph node metastases and to develop a model to quantitatively and repeatedly identify lymph node status.

METHODS

Twenty-seven patients with 137 lymph nodes were identified by two PET/CT images. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of lymph node status were analyzed, and the optimal cut-off value was identified by ROC analysis.

RESULTS

The SUVmax of metastatic lymph nodes on 18F-FAPI was higher than that on 18F-FDG PET/CT (10.87 ± 7.29 vs 6.08 ± 5.37, p < 0.001). 18F-FAPI presented much greater lymph node detection sensitivity, specificity, accuracy, PPV and NPV than 18F-FDG PET/CT (84% vs. 71%; 92% vs. 67%; 90% vs. 69%, 84% vs. 52%, and 92% vs. 83%, respectively). Additionally, the diagnostic effectiveness of 18F-FAPI in small lymph nodes was greater than that of 18F-FDG PET/CT (specificity: 96% vs. 72%; accuracy: 93% vs. 73%; PPV: 77% vs. 33%, respectively). Notably, the optimal cut-off value for specificity and PPV of 18F-FAPI SUVmax was 5.3; the optimal cut-off value for sensitivity and NPV was 2.5.

CONCLUSION

18F-FAPI showed promising diagnostic efficacy in metastatic mediastinal and hilar lymph nodes from lung cancer patients, with a higher SUVmax, especially in small metastatic nodes, compared with 18F-FDG. In addition, this exploratory work recommended optimal SUVmax cutoff values to distinguish between nonmetastatic and metastatic lymph nodes, thereby advancing the development of image-guided radiation. Trial registration ClinicalTrials.gov identifier: ChiCTR2000036091.

Sarcoid-like Reactions to Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression.

[Translated article] Sarcoid-like Reactions to Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) can cause immune-mediated cutaneous adverse events, including sarcoid-like reactions. The aim of this study was to retrospectively analyze clinical and histologic data from patients who developed cutaneous sarcoid-like reactions between 2019 and 2022 while under treatment with ICIs. We studied 7 patients (6 women and 1 man) with a median age of 65years. Median time to onset of symptoms was 4months. The most common presentation was papular sarcoidosis of the knees followed by subcutaneous sarcoidosis. Diagnosis was confirmed histologically in all cases, and no differences were observed relative to idiopathic sarcoidosis. Discontinuation of ICI therapy was required in just two patients. ICI-induced sarcoid-like reactions tend to be mild and generally do not require treatment discontinuation. Histologic confirmation is essential for distinguishing these reactions from tumor progression.

Circulating T cells in sarcoidosis have an aberrantly activated phenotype that correlates with disease outcome

RATIONALE

Disease course in sarcoidosis is highly variable. Bronchoalveolar lavage fluid and mediastinal lymph nodes show accumulation of activated T cells with a T-helper (Th)17.1 signature, which correlates with non-resolving sarcoidosis. We hypothesize that the peripheral blood (PB) T cell phenotype may correlate with outcome.

OBJECTIVES

To compare frequencies, phenotypes and function of circulating T cell populations in sarcoidosis patients with healthy controls (HCs) and correlate these parameters with outcome.

METHODS

We used multi-color flow cytometry to quantify activation marker expression on PB T cell subsets in treatment-naïve patients and HCs. The disease course was determined after 2-year follow-up. Cytokine production was measured after T cell stimulation in vitro.

MEASUREMENTS AND MAIN RESULTS

We observed significant differences between patients and HCs in several T cell populations, including CD8+ and CD4+ T cells, Th1/Th17 subsets, CD4+ T memory stem cells, regulatory T cells (Tregs) and γδ T cells. Decreased frequencies of CD4+ T cells and increased frequencies of Tregs and CD8+ γδ T cells correlated with worse outcome. Naïve CD4+ T cells displayed an activated phenotype with increased CD25 expression in patients with active chronic disease at 2-year follow-up. A distinctive Treg phenotype with increased expression of CD25, CTLA4, CD69, PD-1 and CD95 correlated with chronic sarcoidosis. Upon stimulation, both naïve and memory T cells displayed a different cytokine profile in sarcoidosis compared to HCs.

CONCLUSIONS

Circulating T cell subpopulations of sarcoidosis patients display phenotypic abnormalities that correlate with disease outcome, supporting a critical role of aberrant T cell activation in sarcoidosis pathogenesis.

Splenic sarcoid reaction mimicking metastases in patients after uterine cancer surgery: a report of two cases

BACKGROUND

Tumor-associated sarcoid reactions have been observed with various tumors; however, they have not been reported with uterine cancer. We present two cases of splenic sarcoid reactions that mimicked metastases a few years after uterine cancer surgery.

CASE PRESENTATION

Case 1 involved a 67-year-old female patient diagnosed with endometrial cancer (pT1aN0M0, pStage Ia, grade 1). The patient underwent open total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic lymphadenectomy. Three years after the initial surgery, computed tomography (CT) and positron emission tomography CT showed multiple splenic masses with increasing numbers and sizes. Splenic metastases were diagnosed, and laparoscopic splenectomy was performed. The histopathological analysis revealed sarcoid reactions in the spleen. Case 2 involved a 47-year-old female patient diagnosed with endometrial cancer (pT1aN0M0, pStage Ia, grade 1). The patient underwent laparoscopic total abdominal hysterectomy and bilateral salpingo-oophorectomy with pelvic lymphadenectomy. Two years after the initial surgery, multiple splenic masses were observed. We performed laparoscopic splenectomy for the splenic metastases. Granuloma formations were identified in the splenic specimen and perisplenic lymph nodes that were removed simultaneously, resulting in a final diagnosis of sarcoid reaction. A review of the lymph nodes at the time of the previous uterine surgery revealed granuloma formation. Other than the presence of splenic masses, no findings suggestive of recurrence were observed in these cases. Uterine cancer and sarcoid reactions progressed without recurrence after splenectomy.

CONCLUSIONS

To the best of our knowledge, this is the first report of the late development of splenic sarcoid reactions after uterine cancer surgery. Sarcoid reactions and metastases are difficult to diagnose based on preoperative imaging results. However, reviewing the specimen at the time of the initial resection, the number of lesions, and the clinical findings (other than imaging findings) may aid in the determination of the correct diagnosis.

Nivolumab-induced systemic lymphadenopathy occurring during treatment of malignant melanoma: a case report

Nivolumab is an anti-programmed cell death protein 1 monoclonal antibody that exhibits significant efficacy in treating melanoma and other malignancies. However, various nivolumab-induced immune-related adverse events (irAEs) have been reported, and differentiating irAEs from tumor progression is sometimes difficult. Here, we report a case of reactive lymphadenopathy occurring after treatment with nivolumab. A 56-year-old man with stage IIIC melanoma received adjuvant therapy with nivolumab after wide local excision. He developed systemic lymphadenopathy and autoimmune hemolytic anemia 1 month after receiving seven cycles of nivolumab. Pathological analysis of a cervical lymph node biopsy specimen revealed no metastatic lesion or any other malignancy, including lymphoma. Thus, the patient was diagnosed with nivolumab-induced reactive lymphadenopathy. Systemic corticosteroids were administered to reduce hemolysis, which led to the resolution of lymphadenopathy. When progressive lymphadenopathy is observed in a patient who received immune checkpoint inhibitor therapy, reactive lymphadenopathy should be carefully distinguished from progression to lymphoid metastasis, and biopsy should be performed if needed.

Suspected immune checkpoint inhibitor-induced pulmonary sarcoid reaction in metastatic renal cell carcinoma

We present the case of a 50-year-old male patient with metastatic clear cell renal cell carcinoma (mRCC) who developed a diffuse pulmonary opacification and lymphadenopathy during nivolumab maintenance therapy. This was diagnosed as presumed sarcoid granulomatous inflammatory reaction secondary to immunotherapy, which resolved with holding off therapy and the nivolumab was resumed.