Spontaneous regression of Merkel cell carcinoma in a patient with chronic lymphocytic leukemia: a case report

Occurrence–regression–recurrence of hepatocellular carcinoma without any intervention: A case report

Background

Spontaneous regression of primary liver cancer is a rare event, and currently the exact pathogenesis of spontaneous tumor regression remains unclear.

Case description

Clinical information was collected from a patient with spontaneous regression of liver cancer at our center. The patient was a 41-year-old male. He was admitted to the hospital on 3 May 2019, due to aversion to fatty or greasy food, anorexia, loss of appetite, and abdominal distension. Laboratory examination results included hepatitis B surface antigen positivity, hepatitis B e antigen positivity, and hepatitis B core antibody positivity and tumor marker levels of alpha-fetoprotein 142,938.20 µg/L, abnormal prothrombin 4,599.91 mAU/ml, and carbohydrate antigen 19–9 82.05 U/ml. Upper abdominal enhanced computed tomography indicated right hepatocellular carcinoma with portal vein tumor thrombus formation. The patient declined any treatment. The tumor in the right lobe of the liver completely regressed after 1 year, and the patient is still undergoing follow-up.

Conclusions

We encountered a hepatocellular carcinoma patient who underwent spontaneous regression, but the exact pathogenesis remains unknown. Understanding the pathogenesis of spontaneous regression of hepatocellular carcinoma has the potential to contribute to the development of an effective treatment for hepatocellular carcinoma.

Immune activity in Merkel cell carcinoma

Merkel cell carcinoma (MCC) is widely known as a highly malignant skin cancer. The pathogenesis of MCC, however, remains mysterious due to the extremely small number of cases and its prevalence in the elderly. Despite its high‐grade malignancy, spontaneous regression occurs with some frequency. The immune activity of the tumor underlies this peculiar behavior. In recent years, immune checkpoint blockade therapies, including the anti‐programmed death ligand 1 antibody, have provided successful results. These therapies, however, are ineffective in approximately half the patients with advanced MCC and few treatments are available for those patients. In this review, we summarize the increasing body of evidence relating to the immune activity of MCC and immunological biomarkers. The interesting and sometimes peculiar behavior of MCC, such as their spontaneous regression, is largely due to their high immunosensitivity. Understanding the tumor immunokinetics of MCC should provide critical insight for understanding cancer immunotherapy. Here, we introduce a new classification for MCC according to its immune activity. Combined application of programmed death ligand 1 (a prognostic factor and predictor of the efficacy of immune checkpoint inhibitors in various cancers) with glucose‐6‐phosphate dehydrogenase (a new promising biomarker for MCC) may enable classification of MCC based on its immune status. Whether the new classification can be used to predict the efficacy of immune checkpoint blockade therapies remains to be evaluated in future studies, but the classification may facilitate future treatment selection.

Complete Spontaneous Regression of Merkel Cell Carcinoma After Biopsy: A Case Report and Review of the Literature

Merkel cell carcinoma (MCC) is a rare primary cutaneous neuroendocrine tumor that typically occurs on the head and neck of the elderly and follows an aggressive clinical course. Merkel cell polyomavirus (MCPyV) has been identified in up to 80% of cases and has been shown to participate in MCC tumorigenesis. Complete spontaneous regression of MCC has been rarely reported in the literature. We describe a case of a 79-year-old man that presented with a rapidly growing, 3-cm mass on the left jaw. An incisional biopsy revealed MCC. Additional health issues were discovered in the preoperative workup of this patient which delayed treatment. One month after the biopsy, the lesion showed clinical regression in the absence of treatment. Wide excision of the biopsy site with sentinel lymph node dissection revealed no evidence of MCC 2 months later. The tumor cells in the patient's biopsy specimen were negative for MCPyV by polymerase chain reaction and immunohistochemistry (CM2B4 antibody, Santa Cruz, CA). The exact mechanism for complete spontaneous regression in MCC is unknown. To our knowledge, only 2 previous studies evaluated the presence of MCPyV by polymerase chain reaction in MCC with spontaneous regression. Whether the presence or absence of MCPyV correlates with spontaneous regression warrants further investigation.

Cytological and Immunocytochemical Features of Merkel Cell Carcinoma on Fine Needle Cytology Samples: A Study of 22 Cases

Merkel cell carcinoma (MCC) is an uncommon neuroendocrine small cell tumor derived from the transformation of the homonymous cells in the basal layer of the epidermis. MCC has a generally aggressive course, with a high tendency for local recurrence, lymph node involvement, and distant metastasis. Fine needle cytology (FNC) and immunocytochemistry were used as diagnostic procedures for 22 cases of MCC presented at our institute. All cases of MCC were successfully diagnosed on FNC. Among all of the monoclonal antisera used (CD56, CK20, CK MNF116, neuron-specific enolase (NSE), synaptophysin, and chromogranin), NSE and CD56 showed the highest frequency of positivity. The accuracy of the cytological diagnosis was 100% compared to the corresponding previous or subsequent pathological diagnoses. FNC and immunocytochemistry represent excellent and accurate diagnostic methods to distinguish MCC from other small-cell malignant entities.

Spontaneous regression and recurrence of stage III Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a malignant neuroendocrine carcinoma originating in the skin. It is typically aggressive with a tendency to recur locally and metastasise. There have been several case reports about spontaneous regression of MCC over the past years, but to the best of our knowledge this is the first case of a regional lymph node metastasised MCC with complete spontaneous regression and recurrence. In addition, the primary tumour has an unusual localisation on the foot.

Merkel cell carcinoma with partial B-cell blastic immunophenotype: a potential mimic of cutaneous richter transformation in a patient with chronic lymphocytic lymphoma

Merkel cell polyomavirus (MCPyV) is a DNA virus whose pathogenic mechanisms in Merkel cell carcinoma (MCC) are still being unraveled. Emerging reports of an association between MCPyV and chronic lymphocytic lymphoma (CLL) have begun to broaden our understanding of the oncogenic mechanisms of this virus and the known association between these 2 malignancies. Herein, we report a case of MCC demonstrating a B-cell immunophenotype arising in a patient with CLL being treated with rituximab. In this context, we discuss the differential diagnostic considerations, especially with cutaneous Richter transformation (diffuse large B-cell lymphoma). We also assessed for the presence of MCPyV in both the patient's MCC and the CLL. Finally, we provide a large meta-analysis of patients with CLL and MCC. Patients with both MCC and CLL have a dismal prognosis, with greater than 50% overall mortality within the first year and a half after MCC diagnosis.

Tumor infiltrating immune cells and outcome of Merkel cell carcinoma: a population-based study

PURPOSE

Merkel cell carcinoma (MCC) is a rare skin cancer that often harbors Merkel cell polyomavirus (MCPyV) DNA. The clinical importance of intratumoral immune cells and their associations with MCPyV infection are poorly understood.

EXPERIMENTAL DESIGN

We identified T lymphocytes (CD3-positive cells), T-cell subsets (CD4, CD8, and FoxP3-positive cells), natural killer cells (small CD16-positive cells), and macrophages (CD68 and CD163-positive cells) in tumors of 116 individuals diagnosed with MCC in Finland from 1979 to 2004 using immunohistochemistry and detected MCPyV DNA with quantitative PCR. The associations between immune cell counts, MCPyV DNA, patient and tumor characteristics, and patient outcome were examined.

RESULTS

MCPyV DNA-positive cancers contained higher numbers of CD3(+), CD8(+), CD16(+), FoxP3(+), and CD68(+) cells as compared with MCPyV DNA-negative carcinomas (all P values < 0.05). High intratumoral numbers of CD3(+), CD8(+), or FoxP3(+) cells, and high CD8(+)/CD4(+) or FoxP3(+)/CD4(+) ratios, were significantly associated with favorable overall survival. Individuals with a high tumor CD3(+) count had metastases less often and survived longer, irrespective of the tumor MCPyV status. Tumor CD3(+) count and MCPyV DNA status had independent influence on survival in a Cox multivariable model that also included presence of locoregional metastases at diagnosis and gender as covariates.

CONCLUSIONS

High intratumoral T-lymphocyte counts are associated with favorable survival in MCC. Although the numbers of T cells are generally higher in MCPyV-positive than in MCPyV-negative MCC, high intratumoral T-cell counts are also associated with favorable survival in MCPyV-negative MCC.