Bona fide primary Merkel cell carcinoma of an intraparotid lymph node in a HIV-positive patient

Merkel Cell Carcinoma in the HIV-1/AIDS Patient

Merkel cell carcinoma (MCC) is a highly aggressive, primary neuroendocrine cancer of the skin. The majority of MCC cases are associated with the recently discovered Merkel cell polyomavirus (MCPyV), while the remaining are caused by ultraviolet (UV) light-induced mutations from excessive sunlight exposure. The risk of developing MCC is much higher in the white population relative to all other races. Approximately 10% of all patients with MCC have some form of immunosuppression including HIV-1/AIDS, chronic inflammatory conditions, solid organ transplantation, or hematological malignancies. The age of onset of MCC is lower and the mortality is higher in immunosuppressed individuals than in immune-competent patients. It is plausible that HIV-1/AIDS predisposes to virus-positive MCC, but it should be noted that HIV-1/AIDS increases the risk for developing of UV-induced skin cancers such as cutaneous squamous cell carcinoma and basal cell carcinoma and therefore may also increase the risk for virus-negative MCC. Surgical management is considered standard of care for localized Merkel cell carcinoma with current recommendations advising a wide local excision of the lesion. Most international guidelines support the use of local adjuvant radiotherapy coupled with tumor staging to improve the frequency of cure. For advanced, metastatic, and recurrent MCC, checkpoint blockade inhibitors targeting PD-1 and PD-L1 have shown remarkable activity including durable long-term. MCC in patients living with HIV-1/AIDS are treated with similar modalities as HIV-1 uninfected individuals with MCC.

Inherited and acquired clinical phenotypes associated with neuroendocrine tumors

PURPOSE OF REVIEW

Overview of neuroendocrine neoplasms in the context of their associations with primary and secondary immunodeficiency states.

RECENT FINDINGS

Malignancies of neuroendocrine origin are well known to be associated with hereditary syndromes, including multiple endocrine neoplasia type 1, von Hippel-Lindau syndrome, neurofibromatosis type 1, and tuberous sclerosis. This review includes the X-linked form of hyper-IgM syndrome (XHIGM), due to mutations in the CD40Ligand gene (CD40LG), as an additional inherited disorder with susceptibility to such malignancies, and discusses neuroendocrine tumors (NETs) arising in other immunocompromised states. Of all primary immune deficiency diseases, NETs appear to be unique to XHIGM patients. Outcomes for XHIGM patients with NETs is poor, and the mechanism behind this association remains unclear. In secondary immune deficiency states, NET occurrences were primarily in patients with HIV or AIDS, the autoimmune disease systemic lupus erythematosus and solid organ transplant recipients. Gastroenteropancreatic NETs were most frequent in XHIGM patients, whereas nongastroenteropancreatic-NETs, like Merkel cell carcinoma and small-cell lung carcinoma, affected HIV/AIDS patients. Possible mechanisms as to the nature of these associations are discussed, including chronic infections and inflammation, and CD40-CD40L interactions. Many questions remain, and further studies are needed to clarify the predisposition of patients with XHIGM to the development of NETs. Given that many of these patients present late in their disease state and have poor outcomes, it is imperative to keep a high index of suspicion at the advent of early signs and symptoms. Regular monitoring with laboratory or imaging studies, including tumor markers, may be warranted, for which further studies are needed.

SUMMARY

Of all primary immunodeficiency diseases, NETs appear to be unique to XHIGM, and the mechanism behind this association remains unclear. Outcome for XHIGM patients with NETs is poor, and it is imperative to keep a high index of suspicion at the advent of early signs and symptoms.

Unknown primary Merkel cell carcinoma: 23 new cases and a review

BACKGROUND

Knowledge is limited regarding unknown primary Merkel cell carcinoma (UPMCC).

OBJECTIVE

We sought to document the characteristics and behavior of UPMCC, and determine the most appropriate treatment.

METHODS

A multicenter, retrospective, consecutive study reviewing patients given a diagnosis of UPMCC between 1981 and 2008 was completed. In addition, a literature review of cases of UPMCC was performed.

RESULTS

In all, 23 patients with UPMCC are described and 34 cases from previous reports are compiled. Among the 23 new cases of UPMCC, the average age at diagnosis was 66.0 years; the majority of patients were male (87%) and Caucasian (100% of those reported). One patient was immunosuppressed, and 39% had a history of other cancer. After the initial biopsy, 16 patients had further evaluation of the involved lymph node basin. Half of these had additional positive nodes (8 of 16). The majority of patients had lymph node basin involvement only (78%), whereas 22% had lymph node basin and distant metastasis. The most common lymph node basin involved was inguinal. The median size of the involved lymph node at diagnosis was 5.0 cm. At 2 years, the overall survival of stage IIIB UPMCC was significantly improved versus stage IIIB known primary Merkel cell carcinoma (MCC): 76.9% to 36.4%.

LIMITATIONS

Limited number of cases and retrospective review are limitations.

CONCLUSION

Our data demonstrate improved overall survival in patients with stage IIIB UPMCC versus those with stage IIIB known primary MCC. Because of the unpredictable natural history of UPMCC, we recommend individualization of care based on the details of each patient's clinical presentation.

A Review of Carcinomas Arising in the Head and Neck Region in HIV-Positive Patients

The majority of malignancies arising in the head and neck among patients with AIDS are Kaposi sarcoma and non-Hodgkin lymphoma. Patients with HIV/AIDS are also at increased risk of developing several carcinomas of the head and neck. This paper focuses on these less common, albeit important, carcinomas. An English language literature search identified numerous population-based studies evaluating carcinomas in the head and neck of HIV-positive patients. Published results indicate that patients with HIV/AIDS are at an increased risk of developing mucosal squamous cell carcinoma, nasopharyngeal carcinoma, lymphoepithelial carcinoma of the salivary gland, and Merkel cell carcinoma in this anatomic region. Data also suggest that HIV-positive patients with these cancers present at a younger age, with more aggressive disease and worse prognosis compared to HIV-negative patients. Treatment involves surgical resection with or without radiation therapy and chemotherapy for locally advanced and metastatic disease. AIDS patients, however, are more likely to suffer radiation treatment complications. Highly active antiretroviral therapy (HAART) has not altered the incidence of these malignancies.