Sarcoidosis-like syndrome and lymphadenopathy due to checkpoint inhibitors

The Utility of Laboratory Investigations for the Assessment and Management of Rheumatic Immune Related Adverse Events

Immune checkpoint inhibitors (ICIs) have greatly improved survival of several cancers with historically very poor prognosis. ICIs act by stimulating the patient's own immune system to fight cancer. Simultaneously, this immune activation can lead to immune-related adverse events (irAEs), including rheumatic manifestations (Rh-irAEs). Rh-irAEs mimic primary rheumatic diseases including arthritis, polymyalgia rheumatica, myositis, vasculitis, sarcoidosis, and sicca. This article summarizes the latest evidence regarding the utility of laboratory investigations in Rh-irAEs.

Radiological assessment of immunotherapy effects and immune checkpoint-related pneumonitis for lung cancer

Immune checkpoint inhibitors (ICIs) therapy have revolutionized advanced lung cancer care. Interestingly, the host responses for patients received ICIs therapy are distinguishing from those with cytotoxic drugs, showing potential initial transient worsening of disease burden, pseudoprogression and delayed time to treatment response. Thus, a new imaging criterion to evaluate the response for immunotherapy should be developed. ICIs treatment is associated with unique adverse events, including potential life-threatening immune checkpoint inhibitor-related pneumonitis (ICI-pneumonitis) if treated patients are not managed promptly. Currently, the diagnosis and clinical management of ICI-pneumonitis remain challenging. As the clinical manifestation is often nonspecific, computed tomography (CT) scan and X-ray films play important roles in diagnosis and triage. This article reviews the complications of immunotherapy in lung cancer and illustrates various radiologic patterns of ICI-pneumonitis. Additionally, it is tried to differentiate ICI-pneumonitis from other pulmonary pathologies common to lung cancer such as radiation pneumonitis, bacterial pneumonia and coronavirus disease of 2019 (COVID-19) infection in recent months. Maybe it is challenging to distinguish radiologically but clinical presentation may help.

Granulomatous and Sarcoid-like Immune-Related Adverse Events following CTLA4 and PD1 Blockade Adjuvant Therapy of Melanoma: A Combined Analysis of ECOG-ACRIN E1609 and SWOG S1404 Phase III Trials and a Literature Review

BACKGROUND

Treatment with immune checkpoint inhibitors (ICIs) has been linked to granulomatous and sarcoid-like lesions (GSLs) affecting different organs. This study sought to evaluate GSL incidence in patients with high-risk melanoma treated with cytotoxic T-lymphocyte antigen 4 (CTLA4) or programmed cell death 1 (PD1) blockade adjuvant therapy in two clinical trials: ECOG-ACRIN E1609 and SWOG S1404. Descriptions and GSL severity ratings were recorded.

METHODS

Data were collected from ECOG-ACRIN E1609 and SWOG S1404. Descriptive statistics along with GSL severity grades were reported. Additionally, a literature review for such cases was summarized.

RESULTS

A total of 11 GSL cases were reported among 2878 patients treated with either ICI or with High-Dose Interferon Alfa-2b (HDI) in ECOG-ACRIN E1609 and SWOG S1404 trials. Cases were numerically more commonly reported with ipi10, followed by pembrolizumab, ipi3, and HDI, respectively. Most of the cases were grade III. Further, organs involved included lung, mediastinal lymph nodes, skin and subcutaneous tissue, and eye. Furthermore, a summary of 62 reports in the literature was described.

CONCLUSIONS

GSLs following anti-CTLA4 and anti-PD1 antibody therapy in patients with melanoma were reported unusually. Reported cases ranged in grade from I to III and appeared manageable. Careful attention to these events and their reporting will be essential to better guide practice and management guidelines.

Retrospective study of the incidence of sarcoidosis-like reaction in patients treated with immunotherapy

AIM

To assess the frequency of radiographically evident drug-induced sarcoidosis-like reaction (DISR) in patients treated with anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) therapy, anti-programmed cell death protein 1 (PD-1) therapy, or a combination of both in a single centre.

MATERIALS AND METHODS

The images and medical records of 457 patients with metastatic melanoma or head and neck cancer treated with either anti-CTLA-4 therapy, anti-PD-1 therapy, or a combination of both at University of California medical centre were reviewed retrospectively and the incidence of radiological manifestations of DISR was assessed among these treatment groups.

RESULTS

Radiological manifestations of DISR were found in 19/457 patients (4.1%). The mean interval from the initiation of immunotherapy to development of DISR was 5.5 months (range 2.3-13.5 months). Mean interval from radiological detection of DISR to imaging evidence of resolution was 5.8 months (range 1.6-18.3 months). Three patients out of 81 (3.7%), 11/297 (3.7%), and 5/79 (6.3%) developed sarcoidosis-like reaction after treatment with anti-CTLA-4 antibody, anti-PD-1 antibody, and a combination of both, respectively. Most patients with DISR were asymptomatic and did not require systemic therapy. Most patients did not demonstrate concomitant increased maximum standardised uptake value (SUVmax) in other organs on their integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET)/computed tomography (CT).

CONCLUSIONS

In the present retrospective study of patients treated with immune checkpoint inhibitors (ICIs), DISR occurred in approximately 3.7% of patients treated with either anti-CTLA-4 or anti-PD-1 antibody and 6.3% of patients treated with a combination of both.

Drug-induced sarcoidosis-like reaction three months after BNT162b2 mRNA COVID-19 vaccination: A case report and review of literature

BACKGROUND

A 70-year-old man with hepatitis C virus-related recurrent hepatocellular carcinoma was admitted for further diagnosis of a 1 cm iso-hyperechoic nodule in segment (S) 5.

CASE SUMMARY

Gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) revealed the nodule in S5 with a defect at the hepatobiliary phase, hyperintensity on diffusion weighted imaging (DWI) and hypointensity on apparent diffusion coefficient (ADC) map. Contrast-enhanced computed tomography revealed hypervascularity at the early phase, and delayed contrast-enhancement was observed at the late phase. Contrast-enhanced ultrasound (US) revealed incomplete defect at the late vascular phase. Inflammatory liver tumor, lymphoproliferative disease, intrahepatic cholangiocarcinoma (small duct type) and bile duct adenoma were suspected through the imaging studies. US guided biopsy, however, showed a noncaseating hepatic sarcoid-like epithelioid granuloma (HSEG), and histopathological analysis disclosed spindle shaped epithelioid cells harboring Langhans-type multinucleated giant cells. One month after admission, EOB-MRI signaled the disappearance of the defect at the hepatobiliary phase, of hyperintensity on DWI, of hypointensity on ADC map, and no stain at the early phase.

CONCLUSION

That the patient had received BNT162b2 messenger RNA (mRNA) coronavirus disease 2019 vaccination 3 mo before the occurrence of HSEG, and that its disappearance was confirmed 4 mo after mRNA vaccination suggested that the drug-induced sarcoidosis-like reaction (DISR) might be induced by the mRNA vaccination. Fortunately, rechallenge of drug-induced DISR with the third mRNA vaccination was not confirmed.

Musculoskeletal immune-related adverse events in 927 patients treated with immune checkpoint inhibitors for solid cancer

OBJECTIVE

The prevalence of the musculoskeletal immune-related adverse events (irAEs) is probably underestimated, as most studies report only severe side effects. Our aim was to describe and characterize all musculoskeletal irAEs in a large cohort of patients treated with immune checkpoint inhibitors (ICI).

METHODS

We conducted a retrospective study among patients who received ICI from 07/27/2014 to 05/08/2020 at the medical oncology department of the Institut Paoli-Calmettes, Marseille, France. All medical files were systemically reviewed by a rheumatologist who collected clinical features, time of occurrence, treatment regimen, irAEs management, course and outcomes. We also assessed tumor response 3 months after introduction of ICI, according to severity and treatments used to manage musculoskeletal irAEs.

RESULTS

Among 927 patients treated with ICI for a solid tumor, 118 patients (12.7%) presented a musculoskeletal irAE. Their median age was 66.5, 61% were male, and they mainly had a lung (57.6%) or urological cancer (27.1%). The most frequently involved ICI was an anti PD-1. Arthralgias and myalgias were the most frequent musculoskeletal irAEs (9.8%) and inflammatory rheumatic features were reported in 36 patients (3.9%) with elevated acute phase reactants and negative immunological markers. The median time of onset was 2 months (IC 95% 1.8; 2.7). Tumor response at 3 months did not differ according to musculoskeletal irAE severity, type of manifestation (arthralgias/myalgias versus inflammatory rheumatic features), pain patterns (mechanical versus inflammatory) or irAE treatments.

CONCLUSION

Musculoskeletal irAEs in this large cohort of patients treated with ICI were frequent (12.7%), mostly mild and well tolerated.

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.

Sarcoid-like Granulomatosis Associated with Immune Checkpoint Inhibitors in Melanoma

We aimed to review the clinical and biological presentation of granulomatosis associated with immune-checkpoint inhibitors (ICI) in patients with melanoma and to explore its association with classical sarcoidosis as well as with cancer response to ICI. To this end, a retrospective study on 18 melanoma patients with histologically proven ICI-induced granulomatosis over a 12-year period in a single center, as well as on 67 similar cases reported in the literature, was conducted. Results indicate ICI-induced granulomatosis is an early side effect (median time to onset: 2 months). Its clinical presentation, with predominant (90%) thoracic involvement, histopathological appearance and supposed underlying biology (involving the mTOR pathway in immune cells, Th17 polarization and TReg dysfunction) are indistinguishable from those of sarcoidosis. Moreover, it appears to be associated with ICI benefit (>65% objective response rate). Evolution is generally favorable, and symptomatic steroid treatment and/or ICI discontinuation are rarely necessary. ICI-associated granulomatosis is critical to explore for several reasons. Practically, it is essential to differentiate it from cancer progression. Secondly, this “experimental” sarcoidosis brings new elements that may help to address sarcoidosis origin and pathophysiology. Its association with ICI efficacy must be confirmed on a larger scale but could have significant impacts on patient management and biomarker definition.

The Relationship between Tumor Development and Sarcoidosis in Aspects of Carcinogenesis before and after the Onset of Sarcoidosis

Background and Objectives: It is still unclear whether sarcoidosis is likely to be associated with tumors. In addition, the use of an immune checkpoint inhibitor has been reported to initiate the onset of sarcoidosis. We retrospectively analyzed tumor development before and after the diagnosis of sarcoidosis and examined the impact of having a history of tumors on the activity or the severity of sarcoidosis. Materials and Methods: We recruited 312 consecutive cases of sarcoidosis and analyzed the tumor development before and after the onset of sarcoidosis. Results: Among them, 25 cases were diagnosed with malignant tumor after diagnosis of sarcoidosis. In the analysis of the tumor-development group after diagnosis of sarcoidosis, both serum angiotensin I-converting enzyme and mediastinal lymph node size were significantly reduced at the time of malignant tumor diagnosis compared to at the onset of sarcoidosis, indicating that the decreasing activity of sarcoidosis may be partly associated with tumor development. Furthermore, we examined 34 cases having tumor history before the onset of sarcoidosis and analyzed the effect of tumor history on the severity of sarcoidosis. Cases with a malignant tumor in the past were older and had less complicated organs of sarcoidosis than cases without malignant tumors in the past. Oral corticosteroid therapy was administrated more frequently in cases without malignant tumors in the past, indicating that the history of a malignant tumor may influence the severity of sarcoidosis. Conclusion: These results indicate that tumor development may be partly associated with the activity or severity of sarcoidosis.

Case Report: Hepatic Sarcoid-Like Reaction Associated With Checkpoint Inhibition in a NSCLC Patient and a Literature Review

Immune checkpoint inhibitor (ICI) treatment has dramatically revolutionized the landscape of therapeutic approaches in multiple cancers, particularly, non-small-cell lung cancer (NSCLC). With the increasing use of programmed death-1 (PD-1) inhibitors in the clinic, the emerging toxicity profile presents a novel learning curve for clinicians. Here we report the first case of an NSCLC patient displaying sarcoid/granulomatous-like reaction (SLR, also known as GLR) in the liver during an anti-PD-1 therapy which showed efficacious response of complete regression. Also, this is the first report describing the SLR induced by toripalimab, a novel PD-1 inhibitor. Given this kind of hepatic findings can be easily mistaken as metastasis, even resulting in premature use of second-line treatments. In particular, we briefly review the clinical features of all those cases reporting sarcoidosis and SLRs manifested on different organs during anti-PD-(L)1 therapy. We anticipate that these clinical cases would help to alert the attention of clinicians that SLRs, as a rare immune-related adverse event (irAE), is manageable and that histopathological analysis is necessary before interpreting it as disease progression.

Electrolyte and Acid-Base Disorders associated with Cancer Immunotherapy

Novel immunotherapy drugs have changed the landscape of cancer medicine. Immune checkpoint inhibitors and chimeric antigen receptor T cells are being used and investigated in almost all solid cancers. Immune-related adverse events have been associated with immunotherapies. Acute kidney injury has been the most commonly associated kidney adverse event. In this review, we showcase the several associated electrolyte disorders seen with immunotherapy. Immune checkpoint inhibitors can lead to hyponatremia by several mechanisms, with the syndrome of inappropriate antidiuresis being the most common. Endocrine causes of hyponatremia are rare. Hypokalemia is not uncommon and is associated with both proximal and distal renal tubular acidosis. Hypercalcemia associated with immune checkpoint inhibitors has led to some interesting observations including immune checkpoint inhibitor-induced parathyroid hormone - related peptide production, sarcoid-like granulomas, and hyper-progression of the disease. Hypocalcemia and hyperphosphatemia may be seen with immune checkpoint inhibitor-induced tumor lysis syndrome. Chimeric antigen receptor T cell therapy-associated electrolyte disorders are also common. This is associated chiefly with hyponatremia, although other electrolyte abnormalities can occur. Early recognition and prompt diagnosis may help providers manage the mechanistically varied and novel electrolyte disorders associated with immunotherapy.

Pulmonary adverse events due to immune checkpoint inhibitors: A literature review

Cancer immunotherapy aims to stimulate the immune system to fight against tumors, utilizing the presentation of molecules on the surface of the malignant cells that can be recognized by the antibodies of the immune system. Immune checkpoint inhibitors, a type of cancer immunotherapy, are broadly used in different types of cancer, improving patients' survival and quality of life. However, treatment with these agents causes immune-related toxicities affecting many organs. The most frequent pulmonary adverse event is pneumonitis representing a non-infective inflammation localized to the interstitium and alveoli. Other lung toxicities include airway disease, pulmonary vasculitis, sarcoid-like reactions, infections, pleural effusions, pulmonary nodules, diaphragm myositis and allergic bronchopulmonary aspergillosis. This review aims to summarize these pulmonary adverse events, underlining the significance of an optimal expeditious diagnosis and management.

Surgical perspective on neoadjuvant immunotherapy in non-small cell lung cancer

BACKGROUND

With a 5% improvement in 5-year overall survival achieved with current neoadjuvant or adjuvant chemotherapy, new treatments for resectable non-small cell lung cancer (NSCLC) are urgently needed. The use of immune checkpoint inhibitors (ICI) is established in metastatic NSCLC and is being evaluated in resectable NSCLC.

METHODS

Publications and conference databases and clinicaltrials.gov were searched for reports on clinical studies of neoadjuvant immunotherapy in patients with early resectable NSCLC.

RESULTS

Potential advantages of neoadjuvant ICI include earlier treatment of micrometastatic disease; activation of a broader, potentially durable immune response by the whole tumor and associated lymph nodes; and pathologic assessment of neoadjuvant treatment response, which may guide adjuvant therapy. Surgical considerations include delays to surgery, potential disease progression preventing curative resection, and perioperative morbidity and mortality. Surrogate endpoints of efficacy (pathologic complete response, major pathologic response) and biomarkers predictive of outcome (programmed death ligand 1 expression, tumor mutational burden and circulating tumor DNA) can accelerate clinical trial completion and early-stage treatment development; their application in neoadjuvant ICI studies in NSCLC is reviewed.

CONCLUSIONS

Phase 2 trials of neoadjuvant ICI alone or with chemotherapy showed encouraging safety and efficacy in patients with resectable NSCLC, warranting the ongoing phase 3 studies of neoadjuvant immunotherapy plus chemotherapy. Preoperative and intraoperative unresectability following neoadjuvant ICI appear comparable to neoadjuvant chemotherapy. To help thoracic surgeons and medical oncologists to distinguish amongst ICI beyond efficacy as phase 3 data emerge, surgery-related endpoints for perioperative morbidity, mortality, and complexity should be defined, standardized, incorporated into trial designs, and reported.

An atypical sarcoid-like reaction during anti-protein death 1 treatment in a patient with metastatic melanoma

We report a case of anti-protein death 1-induced sarcoid-like reaction in a 63-year-old Caucasian male who was diagnosed with stage IV-M1a melanoma. He was initially treated with pembrolizumab monotherapy (Q3W) and had a complete response after 14 cycles. However, relapse was suspected 3 months later with appearance of hilar, mediastinal and hepatic hilar lymph nodes as well as a skin lesion. Biopsy of both the hilar lymph nodes and the skin lesion demonstrated sarcomatoid granulomatosis. Pembrolizumab was discontinued temporarily. While on F-FDG-PET/CT, all sarcoid-like lesions regressed in size and activity, a new hypermetabolic solitary skeletal lesion was detected in a lumbar vertebra, suspicious for metastasis. However, since the patient was asymptomatic, a watchful-waiting attitude was taken. During this period, a spontaneous and complete resolution of the metabolic activity was observed of the skeletal lesion. Until today, the patient remains in complete remission. Current case presents an atypical presentation and evolution of anti-PD-1-induced sarcoid-like reaction, illustrating the difficulty of differentiating it from disease progression. Before considering (re-)initiation of anti-melanoma therapy, a tissue biopsy of one of the suspected lesions may be performed to confirm diagnosis. Physicians treating patients with ICI should be aware of this difficulty and critically assess the nature of lesions suspect of progression in patients responding to ICI and presenting with a sarcoid-like reaction.

Granulomatous colitis in a patient with metastatic melanoma under immunotherapy: a case report and literature review

BACKGROUND

Immune checkpoint inhibitors (ICPIs) have changed the way advanced malignancies are currently confronted, improving cancer patients' outcomes but also generating distinct immune-related (ir) adverse events. ICPIs-induced colitis is a common complication showing different clinical and histological manifestations. In the literature review, 14 cases with ICPIs related colon granulomas have been reported in 5 studies with either limited or unavailable information regarding histology. Granulomatous reactions can be mistakenly perceived as disease recurrence or progression. Better understanding and identification of this infrequent histological display can help to avoid misdiagnosis and mismanagement.

CASE PRESENTATION

A 63-year-old female patient with metastatic melanoma was admitted to the hospital with symptoms of nausea, persistent diarrhea and shivering fever under consecutive treatments with ICPIs, initially pembrolizumab and subsequently ipilimumab. Sigmoidoscopy was performed revealing mucosal edema, hyperemia and erosions of the rectum and sigmoid colon. Histological evaluation of sigmoid colon mucosa biopsies revealed an unusual colitis pattern characterized by multiple intracryptal granulomas attributed to ICPIs therapy. Steroids were administered and the patient recovered. ICPIs treatment was discontinued. The patient was subsequently treated with chemotherapy but follow up radiology showed disease progression. A re-challenge with another ICPI regimen was decided and the patient is currently under immunotherapy with stable disease regarding melanoma status and without any sign of colitis recurrence.

CONCLUSIONS

The present report provides detailed histological description of a distinctive ICPIs-induced granulomatous colitis and highlights the need for awareness of the distinct adverse events and reaction patterns in the context of immunotherapy.

Sarcoid-like reaction in cases treated by checkpoint inhibitors

Sarcoidosis is a multisystem granulomatous disorder characterized by helper T cell inflammation. Sarcoid-like reaction (SLR) is a well-defined entity and may be related with several malignant disorders and/or their therapies. SLR has been reported more than 20 years ago and in recent years in cases treated by checkpoint inhibitors (CPIs). Better outcome has been reported in cases developing granulomatous reaction and/or SLRs during CPI treatments. However, these lesions clinically may be thought as disease progression and may cause to stop treatment or alterations. These therapeutic manipulations may be harmful for the patients. Clinicians should be aware of SLRs in cases treated by CPIs and tissues must be sampled and reviewed by an experienced pathologist to avoid misdiagnosis and also unnecessary CPI treatment cessations.Significance StatementClinicians should be aware of sarcoid-like reactions in cases treated by checkpoint inhibitors and tissues must be sampled and reviewed by an experienced pathologist to avoid misdiagnosis and CPI treatment stops.

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

Drug-induced sarcoidosis-like reactions (DISRs) are systemic granulomatous diseases that develop in the context of a new drug onset. Ipilimumab is an immune checkpoint inhibitor (ICI) approved for the treatment of advanced melanoma which has been associated with DISR. Differential diagnosis between tumour progression and DISR by positron emission tomography/computed tomography (PET/CT) in patients treated with an ICI can be a challenge. A 31-year-old woman was diagnosed with a stage IIIB melanoma in her back. Ipilimumab 10 mg/kg was initiated. After 1 month of finishing the treatment a routine, PET/CT showed multiple enlarged mediastinal and hilar lymph nodes FDG-positive. A transbronchial biopsy showed sarcoid-like granulomatous infiltration which favoured the diagnosis of DISR related to ipilimumab. The patient remained asymptomatic and lymphadenopathy regressed progressively after 11 months. Our work highlights the importance of differentiating DISR from tumour progression, before unnecessary changes in therapeutic strategies. PET/CT is a useful diagnostic tool for its follow-up.

A Phase 2 Multi-institutional Study of Nivolumab for Patients With Advanced Refractory Biliary Tract Cancer

Importance

Currently, there is no established second-line systemic treatment for biliary tract cancer (BTC). Preclinical data have demonstrated that the presence of tumor-infiltrating CD8 T cells and programmed cell death 1 ligand 1-expressing tumor cells in the tumor microenvironment of BTC supports the rationale of using programmed cell death 1 protein blockade immunotherapy in BTC.

Objective

To evaluate anticancer activity of nivolumab in patients with advanced refractory BTC.

Design, Setting, and Participants

In this single-group, multicenter phase 2 study of nivolumab, 54 patients with histologically confirmed BTC whose disease progressed while undergoing treatment with at least 1 line but no more than 3 lines of systemic therapy were enrolled between October 5, 2016, and December 26, 2018. Analysis was performed on an intention-to-treat basis.

Interventions

Nivolumab, 240 mg, was delivered intravenously every 2 weeks for 16 weeks, and then 480 mg was delivered intravenously every 4 weeks until disease progression or unacceptable toxic effects occurred.

Main Outcomes and Measures

The primary end point was investigator-assessed objective response rate, and the secondary end points were progression-free survival, overall survival, and incidence of adverse events.

Results

A total of 54 patients (27 men and 27 women; median age, 65 years [range, 28-86 years]) enrolled, and 46 (22 men and 24 women; median age, 65 years [range, 28-86 years]) were examined for objective response with radiologic imaging. The investigator-assessed objective response rate was 22% (10 of 46), including 1 unconfirmed partial response, with a disease control rate of 59% (27 of 46). Central independent review found an objective response rate of 11% (5 of 46), including 1 unconfirmed partial response, with a disease control rate of 50% (23 of 46). All patients who responded to treated (hereafter referred to as responders) had mismatch repair protein-proficient tumors. The median duration of investigator-assessed response was not reached, with a median follow-up of 12.4 months. Among the intention-to-treat population, median progression-free survival was 3.68 months (95% CI, 2.30-5.69 months) and median overall survival was 14.24 months (95% CI, 5.98 months to not reached). Programmed cell death 1 ligand 1 expression in tumors was associated with prolonged progression-free survival (hazard ratio, 0.23; 95% CI, 0.10-0.51; P < .001). The most common treatment-related grade 3 or 4 toxic effects were hyponatremia (3 of 54 [6%]) and increased alkaline phosphatase (2 of 54 [4%]).

Conclusions and Relevance

This study found that nivolumab was well tolerated and showed modest efficacy with durable response in patients with refractory BTC. Further studies are warranted to verify the findings and evaluate biomarkers for improved treatment selection for patients.

Trial Registration

ClinicalTrials.gov Identifier: NCT02829918.

Sarcoidosis: Pitfalls and Challenging Mimickers

Sarcoidosis, a systemic granulomatous disease of unknown etiology, may mimic other conditions at presentation often resulting in delayed diagnosis. These conditions include infections, neoplasms, autoimmune, cardiovascular, and drug-induced diseases. This review highlights the most common sarcoidosis mimics that often lead to pitfalls in diagnosis and delay in appropriate treatment. Prior to invasive testing and initiating immunosuppressants (commonly corticosteroids), it is important to exclude sarcoid mimickers.

Immune checkpoint inhibitor-associated hypercalcaemia

Immune checkpoint inhibitors (CPIs) have recently become a cornerstone for the treatment of different advanced cancers. These drugs have the ability to reactivate the immune system against tumour cells but can also trigger a myriad of side effects, termed immune-related adverse events (irAEs). Although there are numerous reports of CPI-related endocrinopathies, hypercalcaemia as a suspected irAE is not well documented. The mechanisms of CPI hypercalcaemia are not clearly established. However, in our review, four distinct causes emerged: endocrine disease-related, sarcoid-like granuloma, humoral hypercalcaemia due to parathyroid-related hormone and hyperprogressive disease following CPI initiation. Prompt recognition of hypercalcaemia and the institution of therapy can be lifesaving, affording the opportunity to address the underlying aetiology. In this review we discuss the incidence, diagnosis and management of immune-related hypercalcaemia in oncological patients receiving CPI agents.

Challenges in sarcoidosis and sarcoid-like reactions associated to immune checkpoint inhibitors: A narrative review apropos of a case

Sarcoidosis and sarcoid-like reactions (SLRs) may develop in association with various malignancies, as well as in association to certain oncologic drugs, including immune checkpoint inhibitors (ICIs). We aimed to perform a narrative review with regard to the development of ICIs-associated sarcoidosis or SLRs, and to discuss the corresponding diagnostic and therapeutic challenges raised in this scenario. Apropos of a melanoma patient developing SLRs while treated with ipilimumab and nivolumab, we searched for clinically evident, ICIs-associated sarcoidosis or SLRs in the English literature. We recorded the oncologic characteristics, including type of malignancy and type of ICI, the phenotypic characteristics of sarcoidosis/SLRs, as well as the impact on immunotherapy. Including our patient, we identified 80 ICIs-associated sarcoidosis or SLRs cases. Both sexes were equally affected (40 F/40 M) and the most common malignancy was melanoma (65/80, 81.3%). Concerning the oncologic treatment, there was a predilection for pembrolizumab (23/80, 28.7%), followed by the ipilimumab/nivolumab combination (21/80, 26.3%), ipilimumab (18/80, 22.5%), nivolumab (16/80, 20.0%). Although in the majority of the cases (52/80, 65.0%) there was no need for systemic prednisolone for the management of sarcoidosis, a significant proportion of patients finally discontinued ICIs treatment (44/80, 55.0%). Phenotypically, sarcoidosis and SLRs highly imitate oncologic progression posing diagnostic difficulties. A therapeutic dilemma is also raised when there is a need for systemic prednisolone, since the latter may jeopardize the therapeutic efficacy of immunotherapy. Sarcoidosis and SLRs, though rare, can present in oncologic patients treated with ICIs. Clinicians should be aware of this possibility and the related diagnostic and therapeutic challenges they have to face in this scenario.

Abdominal CT manifestations of adverse events to immunotherapy: a primer for radiologists

Immunotherapy is a rapidly growing field within oncology and is being increasingly used in the management of several malignancies. Due to their unique mechanism of action on the immune system and neoplastic cells, the response pattern and adverse events of this novel therapy are distinct from conventional systemic therapies. Accordingly, the imaging appearances following immunotherapy including adverse events are unique and at times perplexing. Imaging is integral to management of patients on immunotherapeutic agents and a thorough understanding of its mechanism, response patterns and adverse events is crucial for precise interpretation of imaging studies. This review provides a description of the mechanism of action of current immunotherapeutic agents and the organ-wise description of their side effects.

Dermatologic toxicities to immune checkpoint inhibitor therapy: A review of histopathologic features

Antineoplastic agents that use the immune system have revolutionized cancer treatment. Specifically, implementation of immune checkpoint inhibitors, monoclonal antibodies that block cytotoxic T-lymphocyte-associated antigen-4, programmed cell death protein 1, or programmed cell death ligand 1 show improved and sustained responses in patients with cancer. However, these agents are associated with a plethora of adverse events, many manifesting in the skin. As the clinical application of cancer immunotherapies expands, understanding the clinical and histopathologic features of associated cutaneous toxicities becomes increasingly important to dermatologists, oncologists, and pathologists to ensure timely diagnosis and appropriate care. This review discusses cutaneous reactions to immune checkpoint inhibitors, focusing on histopathologic features.

EULAR points to consider for the diagnosis and management of rheumatic immune-related adverse events due to cancer immunotherapy with checkpoint inhibitors

Background

Rheumatic and musculoskeletal immune-related adverse events (irAEs) are observed in about 10% of patients with cancer receiving checkpoint inhibitors (CPIs). Given the recent emergence of these events and the lack of guidance for rheumatologists addressing them, a European League Against Rheumatism task force was convened to harmonise expert opinion regarding their identification and management.

Methods

First, the group formulated research questions for a systematic literature review. Then, based on literature and using a consensus procedure, 4 overarching principles and 10 points to consider were developed.

Results

The overarching principles defined the role of rheumatologists in the management of irAEs, highlighting the shared decision-making process between patients, oncologists and rheumatologists. The points to consider inform rheumatologists on the wide spectrum of musculoskeletal irAEs, not fulfilling usual classification criteria of rheumatic diseases, and their differential diagnoses. Early referral and facilitated access to rheumatologist are recommended, to document the target organ inflammation. Regarding therapeutic, three treatment escalations were defined: (1) local/systemic glucocorticoids if symptoms are not controlled by symptomatic treatment, then tapered to the lowest efficient dose, (2) conventional synthetic disease-modifying antirheumatic drugs, in case of inadequate response to glucocorticoids or for steroid sparing and (3) biological disease-modifying antirheumatic drugs, for severe or refractory irAEs. A warning has been made on severe myositis, a life-threatening situation, requiring high dose of glucocorticoids and close monitoring. For patients with pre-existing rheumatic disease, baseline immunosuppressive regimen should be kept at the lowest efficient dose before starting immunotherapies.

Conclusion

These statements provide guidance on diagnosis and management of rheumatic irAEs and aim to support future international collaborations.

Sarcoidosis-like reaction during palbociclib treatment for metastatic breast cancer: A case report

This case report describes a 62-year-old female patient developing a granulomatous sarcoidosis-like reaction in mediastinal lymphatic nodes during a treatment by palbociclib for a metastatic breast carcinoma. After a 3-month treatment associating palbociclib, anastrozole, denosumab, and a single targeted cervical vertebral metastasis radiation therapy, a positron emission tomography showed full regression of breast, vertebral, and axillary node lesion contrasting to new emergent metabolic mediastinal lymph nodes. An endobronchial ultrasound-guided transbronchial needle aspiration revealed a sarcoidosis-like reaction, which dramatically decreased with glucocorticoids.

Clinical characteristics of rheumatic syndromes associated with checkpoint inhibitors therapy

Compared with conventional cancer therapies, the spectrum of toxicities observed with checkpoint inhibitors is unique and can affect any organ system. Arthralgia and myalgia were by far the most commonly reported rheumatic immune-related adverse events in clinical trials, and there is now a growing number of case series and reports describing clinical features of de novo rheumatic immune-related adverse events, which will be the focus of this review. Some patients develop genuine classic rheumatic and musculoskeletal diseases, but a number of rheumatic immune-related adverse events mimic rheumatic and musculoskeletal diseases with atypical features, mainly polymyalgia rheumatica, rheumatoid arthritis and myositis, as well as several systemic conditions, including sicca syndrome, vasculitis, sarcoidosis, systemic sclerosis and lupus.

Checkpoint inhibitor-induced sarcoid choroidal granulomas

Purpose

To present a novel case of sarcoid choroidal granulomas due to nivolumab therapy for metastatic cutaneous melanoma.

Observations

A 55 year-old male with a history of stage III metastatic cutaneous melanoma treated by nivolumab presented with bilateral choroidal lesions. The ophthalmologic examination revealed bilateral creamy, yellow choroidal lesions with no ocular inflammation. The systemic workup revealed pulmonary sarcoidosis confirmed by biopsy.

Conclusion

Nivolumab is an immune checkpoint inhibitor therapy used in the treatment of metastatic melanoma. With the increasing use of immune checkpoint inhibitors in patients with advanced melanoma, clinicians should be aware of this potential associated immune-related adverse event.

Imaging manifestations of immune-related adverse effects in checkpoint inhibitor therapies: A primer for the radiologist

Immune checkpoint inhibitors are monoclonal antibodies directed against cellular pathways on T-cells to treat different types of malignancies. This new therapy can cause immune-related adverse events that can involve almost any organ system. This article will review clinical presentations, molecular mechanisms and imaging manifestations of adverse events caused by checkpoint inhibitors and also illustrate the pseudoprogression tumor response pattern.

Immunotherapy Outcomes in Advanced Melanoma in Relation to Age

INTRODUCTION

Older age is a melanoma risk factor. Elderly individuals are likelier to have immunosenescence, which could help melanoma cells escape immune surveillance. Hence, it is believed that elderly people cannot mount a potent immune response to checkpoint inhibitors to eliminate melanoma.

OBJECTIVES

To investigate age-related differences in the time to progression, overall survival, and immunotherapy-related adverse events among patients with metastatic melanoma who received checkpoint inhibitors.

METHODS

We retrospectively identified patients at our institution between January 2012 and December 2016 with stage IV melanoma who received at least 1 dose of ipilimumab, pembrolizumab, nivolumab, or combined ipilimumab and nivolumab. Demographic, pathologic, and clinical characteristics were obtained. Immune-related response criteria were used to define responses.

RESULTS

Twenty-nine patients were younger than age 65 years and 31 were age 65 years or older. Time to progression was comparable between the age groups (hazard ratio = 0.79, 95% confidence interval = 0.37-1.70, p = 0.46). Overall survival was not significantly different after immunotherapy between groups (hazard ratio = 0.75, 95% confidence interval = 0.31-1.82, p = 0.491). Overall, immunotherapy-related adverse events were comparable between groups, with 62% in younger patients (18/29) and 45% in older patients (14/31 p = 0.19). Of 60 patients, 30 responded to immunotherapy. Nonresponders were more likely than responders to have BRAF-mutated melanomas (16 [53.3%] vs 8 [27.6%]; p = 0.04) and less likely to have immunotherapy-related adverse events (12 [40%] vs 20 [66.7%]; p = 0.04).

CONCLUSION

Aging does not seem to affect response to checkpoint inhibitors. Elderly patients with metastatic melanoma should be treated similarly to younger patients.

[Toxicities of immune checkpoint inhibitors and their management]

Immunotherapeutic strategies, notably immune checkpoint inhibitors, have become a standard of care for the treatment of advanced cancers, with a growing spectrum of activity. These monoclonal antibodies target the co-inhibitory signals between tumor cells or antigen-presenting cells and T cells, thereby enhancing antitumour T cell activity. However, the occurrence of immune-related adverse events, that can affect all organ-system, represents a major limiting factor to the clinical development of these antibodies. Management of such toxicity requires a close collaboration between oncologists and organ-specialists, by using glucocorticoids and/or other immunosuppressive therapies, with the common objective not alter anti-tumor response.

The Importance of Imaging Studies in the Assessment of Response to Immunotherapy in Lung Cancer

Immunotherapy (particularly immune checkpoint inhibitors) in the treatment of patients with lung cancer has aroused great interest in recent years, revolutionized the management of patients with locally advanced/metastatic disease, and given hope to both patients and treating physicians. These drugs, in combination or in monotherapy, have become the standard treatment for many patients with lung cancer, and their use is expected to increase significantly in the near future. In this article, we will review the growing importance of imaging techniques in the evaluation of therapeutic response to immunotherapy in lung cancer patients, with emphasis on the new specific radiological criteria on response to immunotherapy, atypical radiological responses (pseudoprogresion, dissociative responses, hyperprogresion), and the main radiological manifestations of adverse events associated with immunotherapy (sarcoid reactions, pulmonary toxicities, etc.). Pulmonologists must be familiar not only with atypical radiological responses to immunotherapy and their prognostic implications, but also with their effects and the new radiological criteria of response to assess treatment response. In this study, we will address key concepts such as "pseudoprogresion", "paradoxical response", "hyperprogresion", or "unconfirmed progression", and their significance in the management of patients with lung cancer treated with immunotherapy.

Frequency and distribution of various rheumatic disorders associated with checkpoint inhibitor therapy

Immune checkpoint inhibitors have advanced the treatment paradigm of various cancers, achieving remarkable survival benefits. However, a myriad of immune-related adverse events (irAE) has been recognized in almost every organ system, presumably because of persistent immune system activation. Rheumatic symptoms such as arthralgia or myalgia are very common. More specific irAE are increasingly being reported. The most frequent ones are inflammatory arthritis, polymyalgia-like syndromes, myositis and sicca manifestations. These rheumatic irAE can develop in ∼5-10% of patients treated with immune checkpoint inhibitors, although true incidence rates cannot be estimated given the lack of prospective cohort studies, and likely underreporting of rheumatic irAE in oncology trials. In this review, we will provide a summary of the epidemiologic data reported for these rheumatic irAE, until more robust prospective longitudinal studies become available to further define the true incidence rate of rheumatic irAE in patients receiving these novel cancer therapies.

Immunopathogenesis of Immune Checkpoint Inhibitor-Related Adverse Events: Roles of the Intestinal Microbiome and Th17 Cells

The advent of novel, innovative, and effective anti-cancer immunotherapies has engendered an era of renewed optimism among cancer specialists and their patients. Foremost among these successful immunotherapies are monoclonal antibodies (MAbs) which target immune checkpoint inhibitor (ICI) molecules, most prominently cytotoxic T-lymphocyte-associated protein (CTLA-4) and programmed cell death protein-1 (PD-1) and its major ligand, PD-L1. These immunotherapeutic agents are, however, often associated with the occurrence of immune-mediated toxicities known as immune-related adverse events (IRAEs). The incidence of severe toxicities increases substantially when these agents are used together, particularly with CTLA-4 in combination with PD-1 or PD-L1 antagonists. Accordingly, dissociating the beneficial anti-tumor therapeutic activity of these agents from the emergence of IRAEs represents a significant challenge to attaining the optimum efficacy of ICI-targeted immunotherapy of cancer. This situation is compounded by an increasing awareness, possibly unsurprising, that both the beneficial and harmful effects of ICI-targeted therapies appear to result from an over-reactive immune system. Nevertheless, this challenge may not be insurmountable. This contention is based on acquisition of recent insights into the role of the gut microbiome and its products as determinants of the efficacy of ICI-targeted immunotherapy, as well as an increasing realization of the enigmatic involvement of Th17 cells in both anti-tumor activity and the pathogenesis of some types of IRAEs. Evidence linking the beneficial and harmful activities of ICI-targeted immunotherapy, recent mechanistic insights focusing on the gut microbiome and Th17 cells, as well as strategies to attenuate IRAEs in the setting of retention of therapeutic activity, therefore represent the major thrusts of this review.

Hypercalcaemia due to Sarcoidosis during Treatment with Avelumab for Metastatic Merkel Cell Carcinoma

Merkel cell carcinoma is a rare but aggressive skin cancer. Response to chemotherapy is not durable but avelumab, an anti-PD-L1 inhibitor, showed promising ongoing response in a phase II trial. Checkpoint inhibitors including avelumab are known to cause overactivation of the immune system, leading to immune-related adverse events (irAE). We describe the first reported case of hypercalcaemia secondary to reactivation of sarcoidosis in a patient with metastatic Merkel cell carcinoma on avelumab. Hypercalcaemia was managed with corticosteroids to full resolution and avelumab therapy was safely continued.

Exclusive Cutaneous and Subcutaneous Sarcoidal Granulomatous Inflammation due to Immune Checkpoint Inhibitors: Report of Two Cases with Unusual Manifestations and Review of the Literature

Recent emergence of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of cancers and produced prolonged response by boosting the immune system against tumor cells. The primary target antigens are cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), a downregulator of T-cell activation, and programmed cell death-1 receptor (PD-1), a regulator of T-cell proliferation. This enhanced immune response can induce autoimmune adverse effects in many organs. Although skin toxicities are the most common, sarcoidal inflammation with exclusive cutaneous involvement is a rare occurrence with only 6 cases reported to date. We report 2 cases with unusual features. One patient is a female who was treated for metastatic renal cell carcinoma with combination of ipilimumab (anti-CTLA-4) and nivolumab (anti-PD-1). She developed deep nodules showing sarcoidal dermatitis and panniculitis on histopathologic exam. The second patient is a male with melanoma of eyelid conjunctiva who was treated prophylactically with ipilimumab. He presented with papules/plaques confined to black tattoos, where the biopsy revealed sarcoidal dermatitis. By a comprehensive literature review, we intend to raise awareness about this potential skin side effect in the growing number of patients receiving targeted immunotherapies. It is crucial to have a high index of suspicion and perform timely biopsies to implement appropriate management strategies.

Sarcoidosis-like reaction in metastatic triple negative breast cancer treated by anti-PD-L1

We report the first case of sarcoidosis-like reaction in a patient treated by anti-PD-L1 for a breast cancer. A 69-year-old woman presented with a histologically confirmed lung metastasis of a triple negative breast cancer. She was treated by nab-paclitaxel plus anti-PD-L1 in first line. After 2 months, a dramatic lung response was noticed but an involvement of mediastinal lymph nodes appeared. Endoscopic ultrasound-guided fine-needle aspiration of these lymph nodes revealed multiple epitheloid granulomas without caseating necrosis in favour of a sarcoidosis-like reaction. The patient remained free of symptom and in complete lung response on anti-PD-L1 treatment as a maintenance therapy.

Immunotherapy Associated Pulmonary Toxicity: Biology Behind Clinical and Radiological Features

The broader use of immune checkpoint blockade in clinical routine challenges clinicians in the diagnosis and management of side effects which are caused by inflammation generated by the activation of the immune response. Nearly all organs can be affected by immune-related toxicities. However, the most frequently reported are: fatigue, rash, pruritus, diarrhea, nausea/vomiting, arthralgia, decreased appetite and abdominal pain. Although these adverse events are usually mild, reversible and not frequent, an early diagnosis is crucial. Immune-related pulmonary toxicity was most frequently observed in trials of lung cancer and of melanoma patients treated with the combination of the anti-cytotoxic T lymphocyte antigen (CTLA)-4 and the anti-programmed cell death-1 (PD-1) antibodies. The most frequent immune-related adverse event in the lung is represented by pneumonitis due to the development of infiltrates in the interstitium and in the alveoli. Clinical symptoms and radiological patterns are the key elements to be considered for an early diagnosis, rendering the differential diagnosis crucial. Diagnosis of immune-related pneumonitis may imply the temporary or definitive suspension of immunotherapy, along with the start of immuno-suppressive treatments. The aim of this work is to summarize the biological bases, clinical and radiological findings of lung toxicity under immune checkpoint blockade, underlining the importance of multidisciplinary teams for an optimal early diagnosis of this side effect, with the aim to reach an improved patient care.

Checkpoint Inhibitors

BACKGROUND

Treatment with checkpoint inhibitors such as anti-programmed death-1 (anti-PD-1), anti-PD-ligand 1 (anti-PD-L1), and anti-cytotoxic T-lymphocyte antigen-4 (anti-CTLA-4) antibodies can prolong the survival of cancer patients, but it also induces autoimmune side effects in 86-96% of patients by activating the immune system. In 17-59% of patients, these are severe or even life-threatening.

METHODS

This review is based on pertinent articles retrieved by a search in PubMed and on an evaluation of a side-effect registry.

RESULTS

Checkpoint-inhibitor-induced autoimmune side effects manifest themselves in all organ systems, most commonly as skin lesions (46-62%), autoimmune colitis (22-48%), autoimmune hepatitis (7-33%), and endocrinopathies (thyroiditis, hypophysitis, adrenalitis, diabetes mellitus; 12-34%). Rarer side effects include pneumonitis (3-8%), nephritis (1-7%), cardiac side effects including cardiomyositis (5%), and neurological side effects (1-5%). Severe (sometimes lethal) side effects arise in 17-21%, 20-28%, and 59% of patients undergoing anti-PD-1 and anti- CTLA-4 antibody treatment and the approved combination therapy, respectively. With proper monitoring, however, these side effects can be recognized early and, usually, treated with success. Endocrine side effects generally require long-term hormone substitution. Patients who have stopped taking checkpoint inhibitors because of side effects do not show a poorer response of their melanoma or shorter survival in comparison to patients who continue to take checkpoint inhibitors.

CONCLUSION

The complex management of checkpoint-inhibitor-induced side effects should be coordinated in experienced centers. The creation of an interdisciplinary "tox team" with designated experts for organ-specific side effects has proven useful. Prospective registry studies based on structured documentation of side effects in routine clinical practice are currently lacking and urgently needed.

Musculoskeletal and Rheumatic Diseases Induced by Immune Checkpoint Inhibitors: A Review of the Literature

Background:

Immune checkpoint inhibitors are a new promising class of antitumor drugs that have been associated with a number of immune-related Adverse Events (AEs), including musculoskeletal and rheumatic disease.

Methods:

We searched Medline reviewing reports of musculoskeletal and rheumatic AEs induced by immune checkpoint inhibitors.

Results:

Several musculoskeletal and rheumatic AEs associated with immune checkpoint inhibitors treatment are reported in the literature. In particular, arthralgia and myalgia were the most common reported AEs, whereas the prevalence of arthritis, myositis and vasculitis is less characterized and mainly reported in case series and case reports. Other occasionally described AEs are sicca syndrome, polymyalgia rheumatica, systemic lupus erythematosus and sarcoidosis.

Conclusion:

Newly induced musculoskeletal and rheumatic diseases are a frequent adverse event associated with immune checkpoint inhibitors treatment

Small Cell Lung Cancer with Sarcoidosis in Spontaneous Remission: A Case Report

A 69-year-old woman was diagnosed with sarcoidosis, which was not treated with corticosteroid therapy. Her levels of angiotensin converting enzyme decreased significantly over 4 years and a mass lesion was detected near the lower part of her left main bronchus, and diagnosed as small cell lung cancer (SCLC). Treatment of the SCLC with a series of chemotherapeutic agents produced excellent results. The pulmonary sarcoidosis did not show any deterioration despite the frequent use of amrubicin, which is known to be a cause of interstitial pneumonia. This is a case report of SCLC complicated with sarcoidosis in a stage of spontaneous remission, possibly suggesting an association between sarcoidosis and tumor immunity, since recent reports have suggested that immune checkpoint inhibitors might be involved in the development of sarcoidosis.

Panniculitis in a patient with pathologic complete response to talimogene laherparepvec treatment for recurrent, in-transit melanoma

Talimogene laherparepvec (T-VEC) is a novel intralesional oncolytic genetically modified herpes simplex virus type 1 vector for the treatment of unresectable cutaneous, subcutaneous, and nodal melanoma. Although immunological therapies such as T-VEC offer therapeutic promise, they carry a risk of immune-related adverse events (irAEs), the full spectrum of which is incompletely understood. We report a 63-year-old previously healthy man with cutaneous melanoma of the right ankle and progressive right lower extremity in-transit metastases despite systemic therapy with immunomodulatory and molecularly targeted treatments. T-VEC treatment resulted in a complete pathologic response on scouting biopsies. Biopsy of the right lateral calf showed lobular and septal panniculitis with lymphoplasmacytic infiltrate and lipophages. Gomori methenamine silver (GMS) stain and acid-fast bacilli (AFB) stains were negative, and no polarizable foreign material was noted. T-VEC was discontinued due to complete pathologic response and, in part, concern for development of irAEs including this panniculitis and an early concomitant autoimmune colitis. This case highlights a previously unreported irAE with this novel treatment for advanced cases of melanoma.

Immune checkpoint inhibitors and the development of granulomatous reactions

Immune checkpoint inhibitors (ICPIs) have emerged as a frontline treatment for a growing list of malignancies. Disruption of the negative regulatory immune checkpoints by ICPIs has been associated with many immune-related adverse events. Granulomatous reactions, such as sarcoidosis-like reactions, granulomatous panniculitis, granuloma annulare, and granulomatous dermatitis, are uncommon but increasingly recognized immune-related adverse events seen in patients treated with ICPIs. The frequency and significance of these eruptions, including whether they portend responsiveness to treatment, remain unclear. Additionally, understanding the role of immune checkpoint blockade in these reactions may provide mechanistic insight into the relevant signaling pathways involved in sarcoidosis and other granulomatous disorders.

Granulomatous Tumoral Melanosis Associated With Pembrolizumab Therapy: A Mimicker of Disease Progression in Metastatic Melanoma

Immune checkpoint inhibitor therapy has revolutionized the treatment of advanced melanoma, with these agents significantly improving survival for patients with metastatic disease. With the increasing use of these agents, the number of adverse reactions secondary to their use has also increased. Sarcoidosis and sarcoid-like reactions are one such immune checkpoint inhibitor-related adverse event. We report a case of sarcoid-like granulomatous tumoral melanosis in a patient on the programmed cell death-1 (PD-1) receptor inhibitor pembrolizumab for metastatic melanoma. This is, to our knowledge, the first reported case of a sarcoidal form of tumoral melanosis in a patient on anti-PD-1 therapy. We postulate that this reflects tumor regression in response to pembrolizumab-induced immune activation, with concomitant therapy-triggered induction of a sarcoid-like reaction. These findings and the literature review presented herein should alert clinicians and pathologists to the possibility of regressed lesions with sarcoid-like features presenting as mimickers of disease progression in patients undergoing immunotherapy for advanced melanoma.