Applicability of the sentinel node technique to Merkel cell carcinoma

Two separate nodules of Merkel cell carcinoma occurring concomitantly on one cheek

Merkel cell carcinoma (MCC) is a rare and highly aggressive neuroectodermal carcinoma arising from mechanoreceptor Merkel cells. Multiple MCCs are even rarer. We report a case of two independent MCCs simultaneously present in the cheek of a patient, which were effectively and esthetically treated using a cheek flap. Punch biopsy performed in a 60-year-old woman admitted with a chief complaint of two skin-colored hard nodules in her left cheek, accompanied by an itching sensation, was suggestive of MCC. Accordingly, we performed sentinel lymph node biopsy through the modified Blair incision under general anesthesia, in cooperation with the head and neck surgery department. The defect was covered with a cheek flap by slightly extending the existing incision following wide excision with a safety margin of 1 cm. This paper is significant in that it introduces an effective reconstruction technique that maintains function using a cheek flap for the management of this rare case. In addition, this paper is the first to classify multiple MCCs according to the time of onset. We believe that this paper presents an effective alternative reconstruction technique with sentinel node biopsy through the modified Blair incision.

Systematic review of sentinel lymph node biopsy in Merkel cell carcinoma of the head and neck

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine tumor arising on the head and neck in 40%-50% of patients. Between 20% and 40% will harbor subclinical nodal metastasis.

METHODS

Using search terms 'Merkel AND sentinel', MEDLINE, PUMED, and EMBASE databases were systematically reviewed for publications regarding sentinel lymph node biopsy (SLNB) in classification I and II MCC of the head and neck.

RESULTS

Twenty-nine publications encompassing 136 patients were included. The SLNB finding was positive in 42 patients (30.9%). Primary MCC was located on the malar/zygomatic (34.4%), forehead/frontal (13.5%), and nasal (13.5%) regions. Recurrence in an SLNB negative nodal basin result occurred in 10 patients (false negative rate of 19.2%). Site of primary MCC was not associated with a false-negative SLNB result; however, there was a non-statistically significant trend for increased frequency among midline lesions.

CONCLUSIONS

Sentinel lymph node biopsy (SLNB) is recommended for eligible patients with classification I and II head and neck MCC.

Sentinel lymph node biopsy in Merkel cell carcinoma: a 15-year institutional experience and statistical analysis of 721 reported cases

Merkel cell carcinoma (MCC) is a rare aggressive cutaneous neuroendocrine malignancy that frequently metastasizes to the regional lymphatic basin. Pathological assessment of regional lymph nodes with sentinel lymph node biopsy (SLNB) in patients without clinical involvement has permitted more accurate staging and more appropriate management. Nonetheless, concerns have been raised regarding the accuracy of this technique and its prognostic implications. We conducted a review of previously published data analysing the positive and false negative rates of SLNB in MCC. A search of the Medline and Embase databases to April 2015 identified 36 published studies between 1997 and 2015 comprising 692 patients. With the addition of 29 patients treated at our own institution, we conducted an analysis of 721 patients. Among this cumulative cohort, SLNBs were performed from 736 regional sites with 29·6% recorded as positive. Regional metastasis occurred in 45 cases following a negative SLNB, for a false negative rate of 17·1%. Adjuvant regional radiotherapy in the setting of a negative SLNB did not affect regional recurrence (P = 0·31), providing credence to emerging evidence that regional therapy can be safely omitted in the setting of a negative SLNB. Distant relapse was noted far more frequently following a positive rather than negative SLNB (17·6% vs. 7·3%, P < 0·001).

A systematic review of patients with Merkel cell carcinoma of the head and neck and a negative sentinel lymph node biopsy

Background

A negative sentinel lymph node biopsy (SLNB) from patients with head and neck Merkel cell carcinoma (HNMCC) may allow the patient to avoid further adjunctive therapies. However, there is considerable regional variability of lymphatic drainage from primary sites involving the head and neck, and Merkel cell carcinoma (MCC) has aggressive biologic behavior.

Objective

The primary aim of this systematic review was to document the incidence of regional recurrence and mortality from HNMCC patients after a negative SLNB.

Methods

A systematic search of the English literature was conducted via Ovid Medline and Embase from inception until 2013 and the Cochrane Central Register of Controlled Trials from 1991 to January 2014.

Results

Twenty-three studies, with a total of 81 patients matched the inclusion criteria. The incidence of regional recurrence from the entire cohort was 12.3%, and there was a 5% mortality rate. The mean follow-up time, excluding the 30 patients who did not have individual follow-up times specified, was 32.8 months.

Limitations

This review included studies had variable follow-up durations and treatments for MCC.

Conclusions

Despite negative pathologic staging of the neck using SLNB in HNMCC patients, there is still a high incidence of regional recurrence and mortality, over a short follow-up period.

•

Merkel cell carcinoma is an aggressive neoplasm.

•

Patients with a negative sentinel lymph node biopsy from head and neck Merkel cell carcinoma showed a high incidence of future regional lymph node involvement.

•

In this context, a negative sentinel lymph node biopsy is not necessarily reassuring for the patient or the clinician.

Prognostic significance of sentinel lymph node mapping in Merkel cell carcinoma: systematic review and meta-analysis of prognostic studies

Aim. To assess through a systematic review and meta-analysis of the literature the prognostic implication of sentinel lymph node mapping in Merkel cell carcinoma (MCC). Materials and Methods. PubMed and SCOPUS databases were searched by using “Merkel AND sentinel” as keywords. All studies with prognostic information regarding SLN mapping in cN0 MCC patients were included. Hazard ratio (HR) for overall survival (OS) and disease free survival (DFS) was used as effect size. Results. SLN biopsy predicted better DFS and OS as compared to the nodal observation in cN0 MCC patients (pooled HR for DFS: 1.61 (95% CI: 1.05–2.46), P = 0.028; pooled HR for OS: 1.08 (95% CI: 0.55–2.10), P = 0.8). Pathologically negative SLN (SLN−) patients had better OS (pooled HR: 4.42 (95% CI: 1.82–10.7), P = 0.0009) and DFS (pooled HR: 2.58 (95% CI: 1.78–3.73)) as compared to SLN+ patients. Conclusion. SLN mapping can provide strong prognostic information regarding OS and DFS in cN0 MCC patients. More importantly, SLN mapping can improve DFS and possibly OS in cN0 MCC patients as compared to nodal observation. As MCC is a rare tumor, large multicenter prospective studies are still needed to validate the survival benefit of SLN mapping.

Role of sentinel lymph node biopsy in patients with Merkel cell carcinoma: statistical analysis of 403 reported cases

BACKGROUND

Merkel cell carcinoma (MCC) is a rare cutaneous malignancy with a high rate of nodal metastasis. Sentinel lymph node biopsy (SLNB) is used in MCC and other cancers to identify regional node micrometastases in patients with clinically negative nodes; however, whether SLN status is associated with recurrence or prognosis in MCC is unclear.

METHODS

A statistical analysis was performed of 397 published cases of MCC with SLNB results from 22 reports and 6 new cases, in order to elucidate any correlation between SLN status and recurrence, and to determine false-negative rates for SLNB.

RESULTS

Of these 403 cases, 128 (31.8 %) had positive SLNs; 16 of these 128 (12.5 %) developed recurrence (6 nodal, 10 distant). Of 275 patients with negative SLNs, 27 (9.8 %) developed recurrence (19 nodal, 8 distant). Patients with positive SLNs had a greater risk of distant metastasis (OR 2.82; P = 0.037; 95 % CI 1.089-7.347). The false-negative rate for SLNB in all 403 patients was 12.9 %. Use of the immunohistochemical approach to diagnosis of micrometastasis with anti-CK20 antibody did not affect the false-negative rate.

CONCLUSIONS

Patients with positive SLNs had a greater risk of distant metastasis in MCC; positive SLN was an important prognostic factor in MCC. Further studies using standardized, more-sensitive techniques to examine entire SLNs may decrease the false-negative rate, and improve the significance of SLNB in MCC.

Role of sentinel lymph node biopsy in the management of merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare and typically aggressive form of skin cancer. It most commonly affects the elderly and has a predilection for the sun-exposed skin of the head and neck region. Other etiological factors include immune suppression, organ transplantation, and polyoma virus infection. MCC has a propensity to spread to regional lymphatics with a high locoregional recurrence rate. Since its discovery in 1972, treatment paradigms have shifted, with no consensus on optimal management strategies. Currently, standard of care includes surgical intervention to the primary and locoregional site with adjuvant radiotherapy for high-risk disease. In this paper, we discuss the history, pathology, and epidemiology of this rare disease with a focus on the evidentiary basis of treatment protocols. The use of sentinel lymph node biopsy as a management option will be the focus of this paper.

[The role of lymphoscintigraphy in the treatment of Merkel´s cells carcinoma]

The Merkel cell carcinoma is a rare, serious, neuroendocrine, malignant skin cancer with lymph node involvement in half of patients and disseminated metastases in 20% of cases at the time of pathological diagnosis. Its treatment is not fully established, though the sentinel lymph node has been considered essential and may bring benefits to the therapeutic armamentarium of patients.

Merkel cell carcinoma in a young pregnant woman

SUMMARY

We present a 27-year-old pregnant woman with Merkel cell carcinoma on the forehead. In early pregnancy, the lesion was excised as an epidermal cyst. It was only after recurrence that a diagnosis of Merkel cell carcinoma was made. Sentinel-node biopsy, excision with 2 cm margins and reconstruction with free microvascular radial forearm flap was carried out, and the patient received postoperative radiotherapy. No evidence of recurrence or disease progression was found 24 months after surgery.

Management of merkel cell carcinoma: the roles of lymphoscintigraphy, sentinel lymph node biopsy and adjuvant radiotherapy

BACKGROUND

Merkel cell carcinoma (MCC) is an uncommon, highly aggressive skin malignancy with a propensity to recur locally and regionally. However, its optimal treatment is uncertain. In this study, we aimed to assess the roles of lymphoscintigraphy and sentinel node (SN) biopsy, as well as radiotherapy, in the treatment of MCC.

PATIENTS AND METHODS

A retrospective analysis of 17 patients diagnosed with MCC (median age 74 years) over a 7-year period (median follow-up 16 months) was performed.

RESULTS

Of 11 patients. 3 had a positive SN biopsy and, despite adjuvant radiotherapy, 2 of these 3 developed regional lymph node (RLN) recurrence. Of the remaining 8 patients who had a negative SN biopsy, however, 5 also had RLN recurrences. There were 9 patients who received adjuvant radiotherapy (RT) to the primary site, with no in-field recurrences; and 8 who received RT to their RLN field, with only 2 developing regional nodal recurrences-both were SN biopsy positive. During the follow-up period, 2 patients died, only 1 due to MCC.

CONCLUSION

The results suggest that SN status may not be an accurate predictor of loco-regional recurrence in MCC. However, they strongly reinforce previous reports that radiotherapy, both locally and to regional nodes, provides effective infield disease control.

A comprehensive review of the treatment of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an uncommon but malignant cutaneous neuroendocrine carcinoma with a high incidence of local recurrence, regional lymph node metastases, and subsequent distant metastases. The etiology of MCC remains unknown. It usually occurs in sun-exposed areas in elderly people, many of whom have a history of other synchronous or metachronous sun-associated skin lesions. The outcome for most patients with MCC is generally poor. Surgery is the mainstay of treatment. The role of adjuvant therapy has been debated. However, data from recent development support a multimodality approach, including surgical excision of primary tumor with adequate margins and sentinel lymph node dissection followed by postoperative radiotherapy in most cases, as current choice of practice with better locoregional control and disease-free survival. Patients with regional nodal involvement or advanced disease should undergo nodal dissection followed by adjuvant radiotherapy and, perhaps, systemic platinum-based chemotherapy in most cases.

A Primer of Mohs Micrographic Surgery: Uncommon Indications

Mohs micrographic surgery has been used for the treatment of tumors other than basal and squamous cell carcinomas. Parameters to be considered when deciding on a treatment include location, size, growth pattern, and recurrence rates. It is important to consider that sometimes the high-risk nature of the tumor is more significant than the need for tissue sparing. Modifications to the Mohs micrographic surgery technique may be used to ensure diagnostic accuracy and confirm complete removal of the lesion (e.g., immunohistochemical staining and paraffin-embedded sections).

Lymphatic mapping and sentinel node biopsy in Merkel's cell carcinoma

AIM

The purpose of this study was to determine the predictive value of lymphatic mapping with selective lymphadenectomy in patients with Merkel's cell carcinoma.

METHODS

Eight patients with biopsy proven Merkel's cell carcinoma underwent sentinel node biopsy. Lymphoscintigraphy was performed the day before surgery following intradermal injection of 74-111MBq of 99mTc-nanocolloid divided into four doses around the biopsy scar. Dynamic and static images were obtained.

RESULTS

At least one sentinel node was visualized in all patients. The sentinel node was intra-operatively identified with the aid of a hand-held gamma probe in all cases and patent blue dye in six out of eight cases. During surgery, all sentinel nodes were successfully harvested. Metastatic cell deposits were subsequently identified in three patients (37.5%) and they underwent regional lymphadenectomy. No additional involved lymph nodes were identified. No recurrence has been reported in a median follow-up of 4.6 years (range: 8 months-10 years).

CONCLUSIONS

In conclusion, sentinel node biopsy in patients with Merkel's cell carcinoma appears to be a reliable staging technique.

Merkel Cell Carcinoma: Is there a Role for 2-Deoxy-2-[F-18]fluoro-d-glucose-Positron Emission Tomography/Computed Tomography?

PURPOSE

2-Deoxy-2-[F-18]fluoro-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) is becoming widely available as a powerful imaging modality, combining the ability to detect active metabolic processes and their morphologic features in a single study. The role of FDG-PET/CT is proven in lymphoma, melanoma, colorectal carcinoma, and other cancers. However, there are rare malignancies such as Merkel cell carcinoma that can potentially be evaluated with PET/CT. We were therefore prompted to review our experience with FDG-PET/CT in the management of patients with Merkel cell carcinoma.

PROCEDURES

This is a retrospective case series of six patients with Merkel cell carcinoma, 58-81 years old (average 69 +/- 8.3), who had whole-body PET/CT at our institution from January 1st, 2003 to August 31st, 2005. Two patients were women and four were men. Reinterpretation of the imaging studies for accuracy and data analysis from medical records were performed.

RESULTS

Twelve examinations were acquired for the six patients (one patient had six PET/CT, one patient had two PET/CT, and four patients had one PET/CT). The injected FDG doses ranged 381.1-669.7 MBq (average 573.5 +/- 70.3). Four patients had the PET/CT as part of initial staging, and two patients had the exam for restaging (after surgery and XRT). A total of six Merkel lesions (pancreas, adrenal, lip, submandibular lymph nodes, cervical lymph nodes, and parapharyngeal soft tissue) were identified in three patients and confirmed on histopathological examination. The FDG uptake in these areas was intense, with maximum standardized uptake value (SUVmax) values of 5-14 (average 10.4 +/- 3.8). In one patient, the PET/CT scan identified abnormal focal distal sigmoid uptake that was biopsied and diagnosed as adenocarcinoma. Two patients had negative scans and had no clinical evidence of disease on follow-up office visits (up to one year after PET/CT).

CONCLUSIONS

This case series suggests that FDG-PET/CT may have a promising role in the management of patients with Merkel cell carcinoma.

Merkel cell carcinoma

Background

Merkel cell carcinoma (MCC) is an unusual primary neuroendocrine carcinoma of the skin. MCC is a fatal disease, and patients have a poor chance of survival. Moreover, MCC lacks distinguishing clinical features, and thus by the time the diagnosis is made, the tumour usually have metastasized. MCC mainly affects sun-exposed areas of elderly persons. Half of the tumours are located in the head and neck region.

Methods

MCC was first described in 1972. Since then, most of the cases reported, have been in small series of patients. Most of the reports concern single cases or epidemiological studies. The present study reviews the world literature on MCC. The purpose of this article is to shed light on this unknown neuroendocrine carcinoma and provide the latest information on prognostic markers and treatment options.

Results

The epidemiological studies have revealed that large tumour size, male sex, truncal site, nodal/distant disease at presentation, and duration of disease before presentation, are poor prognostic factors. The recommended initial treatment is extensive local excision. Adjuvant radiation therapy has recently been shown to improve survival. Thus far, no chemotherapy protocol have achieved the same objective.

Conclusion

Although rare, the fatality of this malignancy makes is important to understand the etiology and pathophysiology. During the last few years, the research on MCC has produced prognostic markers, which can be translated into clinical patient care.

Biopsia selectiva de ganglio centinela en tumores cutáneos no melanoma

PURPOSE

To assess the feasibility of the Sentinel lymph node biopsy (SLNB) technique in cutaneous non-melanoma malignancies.

MATERIALS AND METHODS

Nine patients were retrospectively evaluated performing a scintigraphy with 99mTc-nanocolloid. On the day of the surgery, an initial dynamic study and static images were obtained. The first drainage station visualized was considered the sentinel node (SLN). The SLN position was marked on the skin and after a correct localization in the surgical field with a gamma probe the SLN was obtained. Patients of this study have been followed up for 8 to 48 months.

RESULTS

Lymphoscintigraphy detected the sentinel node in 88,8 % of our studies (the SLN was not observed in a patient with a Merkel's tumour on the back). The SLN was identified intraoperatively in those patients with positive imaging. Those cases without scintigraphic demonstrated migration were also not found intraoperatively. Histopathological analysis of the SLN showed non metastatic disease and none patient developed metastases or local recurrence in the monitoring period.

CONCLUSIONS

Sentinel node biopsy can be applied to certain cutaneous non-melanoma malignancies. In patients with unclear drainage and to avoid unnecessary lymphadenectomy, the technique offers clear advantages. In our study the SLN analysis was related to the clinical progress. A large number of patients should be examined to truly assess the benefit of this technique in this kind of malignancies and to determinate when the technique must be performed.

Impact of sentinel lymph node biopsy in patients with Merkel cell carcinoma: results of a prospective study and review of the literature

PURPOSE

Merkel cell carcinoma (MCC) is the most aggressive of the cutaneous malignancies, showing a propensity to spread to regional lymph nodes (LNs). The aim of this prospective study was to examine the feasibility and clinical impact of sentinel lymph node biopsy (SLNB) in this cutaneous malignancy.

METHODS

The study population comprised 23 patients with stage I MCC (median age 70 years, range 50-85 years). Lymphoscintigraphic mapping with( 99 m)Tc-nanocolloid was performed in all patients. Sentinel lymph nodes (SLNs) were identified, excised and analysed in serial sections by conventional histopathology and cytokeratin-20 immunohistochemistry.

RESULTS

Metastatic disease was determined in the SLNs of 11 patients (47.8%). Elective lymph node dissection (ELND) was performed in eight of these 11 patients, four of whom had additional positive LNs. During follow-up (median 36.1 months, range 3-79 months), seven of the 23 patients (30%) relapsed: four had a local recurrence and three, in-transit metastases. Recurrence developed in two SLN-negative patients with local LN metastases and in one SLN-positive patient with distant metastases. This patient died, representing the only tumour-related death in our sample. Median survival was 49.1 and 35.5 months for SLN-negative and SLN-positive patients, respectively. This difference was not statistically significant (p=0.3452).

CONCLUSION

SLNB allows for exact nodal staging in patients with MCC. Whether additional ELND is of further benefit remains unclear.

Merkel cell carcinoma of skin: diagnosis and management strategies

Merkel cell carcinoma (MCC) of the skin is a rare form of cutaneous malignancy of neuroendocrine origin with a propensity to affect predominately elderly patients in sun-exposed areas. The tumour has an extremely aggressive growth pattern with the potential to seed into the dermal lymphatics at an early stage as well as spread to nodes and distant sites. Successful outcomes can be achieved with early diagnosis and a multidisciplinary approach to management. Patients with MCC should be carefully staged to exclude distant metastatic disease. Treatment should be approached with both the primary site and the lymph nodes in mind. The primary site should be excised with clear margins, followed by postoperative radiotherapy to the primary site and affected nodes. Addition of chemotherapy to patients perceived to be at high-risk of distant recurrence (e.g. those with involved nodes) has been considered, but evidence supporting this approach is relatively scant. This treatment strategy needs to be approached with caution in the elderly because of the risk of myelosuppression. An aggressive treatment approach is warranted at the first attempt to treat MCC as treatment for recurrent disease is less likely to be successful.

Merkel cell carcinoma: changing incidence trends

BACKGROUND

The objective of this study was to define the incidence trends of Merkel cell carcinoma (MCC), a rare and aggressive cutaneous malignancy.

MATERIALS AND METHODS

All cases of MCC of the skin between 1986 and 2001 were identified using the surveillance, epidemiology, and end results (SEER) program. Overall age-adjusted, gender-specific, age-specific, stage-specific, and regional incidence rates were calculated. All rates are per 100,000 and age-adjusted to the 2000 US standard population. Estimated annual percent change (EAPC) was calculated using a linear least squares model.

RESULTS

A total of 1,124 cases of MCC were identified in the SEER registries. The rate of MCC increased from 0.15 cases per 100,000 in 1986 to 0.44 cases per 100,000 in 2001. The EAPC for the time period was 8.08%. This was statistically significant (95% CI: 6.29, 9.90, P-value < 0.05). Age-specific incidence (5-year age groups) were highest in the elderly, 4.28 per 100,000 in the 85+ age group.

CONCLUSIONS

MCC incidence rates have increased threefold over the 1986-2001 period. Rates are highest in the elderly population. Further etiologic studies and identification of high-risk populations are warranted.

Sentinel lymph node biopsy progress in surgical treatment of cancer

BACKGROUND

Forty-three years after the first description of the sentinel lymph node technique in malignant tumours of the parotid by Gould, sentinel lymph node biopsy (SNLB) has become a precious tool in the treatment of solid tumours.

METHODS

In the following review we give a synopsis of the fundamentals of the sentinel lymph node concept and then proceed to an overview of recent advances of SNLB in gastrointestinal cancers.

RESULTS

In some tumour entities, SNLB has been shown to reflect reliably the lymph node status of the tumour-draining lymph node basin. In melanoma and breast cancer, it became a widely accepted element of the routine surgical management of these malignant diseases. In gastrointestinal tumours, the technique is currently under intense investigation. First reports on its application in other solid tumours, such as non-small cell lung cancer, thyroid carcinoma, oropharyngeal carcinoma, vulvar carcinoma, and Merckel cell carcinoma of the skin, were published more recently.

CONCLUSION

SNLB has become an important component of diagnosis and treatment of solid tumours. A growing number of publications on SNLB in gastrointestinal cancer documents the interest of many investigators in the application of this technique in this tumour entity. As long as imaging techniques like 18FDG PET or other molecular imaging techniques are limited by their spatial resolution, SNLB remains the technique of choice for lympho-nodal staging.

Merkel cell carcinoma

Merkel cell carcinoma is a rare cutaneous neoplasm most commonly affecting the head and neck of elderly white patients. Even with treatment, Merkel cell carcinoma has a strong propensity toward local recurrence, lymphatic spread, and distant metastasis. Because of its rarity and the subsequent lack of well-controlled clinical trials, no single standard of care exists for the treatment of this aggressive tumor. In our institution, primary lesions are excised with wide margins or by Mohs' micrographic surgery. After local removal, the excision site is treated locally with external radiation therapy. Sentinel lymph node mapping and biopsy are performed. Patients with tumor within a sentinel lymph node undergo lymph node dissection and radiation to the lymphatic basin. Adjuvant chemotherapy is offered to high-risk patients with local disease and to patients with metastases. Patients with distant metastases are treated with a combination of salvage chemotherapy and radiation therapy.

Eyelid Merkel Cell Carcinoma: Report of Three Cases

PURPOSE

To present three cases of Merkel cell carcinoma, a primary cutaneous neuroendocrine tumor that arises from Merkel cells, and to describe their clinical features, diagnosis, and management.

METHODS

Case series.

RESULTS

In only one case, the disease was clinically recognized. In the others, the diagnosis was confirmed by histology, and chalazion was initially suspected in one of them. Surgery was performed in all patients, and there was no evidence of metastatic disease.

CONCLUSIONS

The rarity of eyelid Merkel cell carcinoma and the fact that it can simulate benign entities frequently lead to difficulties in diagnosis and a delay in the establishment of suitable therapy.

Candidate???s Thesis: The Application of Sentinel Node Radiolocalization to Solid Tumors of the Head and Neck: A 10-Year Experience

OBJECTIVES/HYPOTHESIS

The goals of the research study were to develop an easily mastered, accurate, minimally invasive technique of sentinel node radiolocalization with biopsy (SNRLB) in the feline model; to compare it with blue-dye mapping techniques; and to test the applicability of sentinel node radiolocalization biopsy in three head and neck tumor types: N0 malignant melanoma, N0 Merkel cell carcinoma, and N0 squamous cell carcinoma.

STUDY DESIGN

Prospective consecutive series studies were performed in the feline model and in three head and neck tumor types: N0 malignant melanoma (43 patients), N0 Merkel cell carcinoma (8 patients), and N0 squamous cell carcinoma (20 patients).

METHODS

The technique of sentinel node radiolocalization with biopsy was analyzed in eight felines and compared with blue-dye mapping. Patterns of sentinel node gamma emissions were recorded. Localization success rates were determined for blue dye and sentinel node with radiolocalization biopsy. In the human studies, all patients had sentinel node radiolocalization biopsy performed in a similar manner. On the morning of surgery, each patient had sentinel node radiolocalization biopsy of the sentinel lymph node performed using an intradermal or peritumoral injection of technetium Tc 99m sulfur colloid. Sentinel nodes were localized on the skin surface using a handheld gamma detector. Gamma count measurements were obtained for the following: 1) the "hot" spot/node in vivo before incision, 2) the hot spot/node in vivo during dissection, 3) the hot spot/node ex vivo, 4) the lymphatic bed after hot spot/node removal, and 5) the background in the operating room. The first draining lymph node(s) was identified, and biopsy of the node was performed. The radioactive sentinel lymph node(s) was submitted separately for routine histopathological evaluation. Preoperative lymphoscintigrams were performed in patients with melanoma and patients with Merkel cell carcinoma. In patients with head and neck squamous cell carcinoma, the relationship between the sentinel node and the remaining lymphatic basin was studied and all patients received complete neck dissections. The accuracy of sentinel node radiolocalization with biopsy, the micrometastatic rate, the false-negative rate, and long-term recurrence rates were reported for each of the head and neck tumor types. In the melanoma study, the success of sentinel node localization was compared for sentinel node radiolocalization biopsy, blue-dye mapping, and lymphoscintigraphy. In the Merkel cell carcinoma study, localization rates were evaluated for sentinel node radiolocalization biopsy and lymphoscintigraphy. In the head and neck squamous cell carcinoma study, the localization rate of sentinel node radiolocalization biopsy and the predictive value of the sentinel node relative to the remaining lymphatic bed were determined. All results were analyzed statistically.

RESULTS

Across the different head and neck tumor types studied, sentinel node radiolocalization biopsy had a success rate approaching 95%. Sentinel node radiolocalization biopsy was more successful than blue-dye mapping or lymphoscintigraphy at identifying the sentinel node, although all three techniques were complementary. There was no instance of a sentinel node-negative patient developing regional lymphatic recurrence. In the head and neck squamous cell carcinoma study, there was no instance in which the sentinel node was negative and the remaining lymphadenectomy specimen was positive.

CONCLUSION

In head and neck tumors that spread via the lymphatics, it appears that sentinel node radiolocalization biopsy can be performed with a high success rate. This technique has a low false-negative rate and can be performed through a small incision. In head and neck squamous cell carcinoma, the histological appearance of the sentinel node does appear to reflect the regional nodal status of the patient.

Sentinel lymphonodectomy in nonmelanoma skin malignancies

BACKGROUND

Whereas the value of sentinel lymphonodectomy (SLNE) in malignant melanoma is established, experience with SLNE in nonmelanoma skin cancers is limited.

OBJECTIVES

The feasibility of SLNE in nonmelanoma skin tumours is evaluated.

METHODS

Thirty-seven patients with high-risk nonmelanoma skin tumours underwent SLNE: 11 squamous cell carcinomas (SCCs), seven Merkel cell carcinomas (MCCs), five cutaneous lymphomas, eight adnexal carcinomas and six other skin cancers, all clinical stage N0.

RESULTS

In nine patients (four MCCs, two SCCs, three lymphomas) the sentinel lymph nodes (SLNs) showed histological evidence of microinvolvement. In five of these nine patients, radical lymph node dissection (RLND) was performed, revealing further micrometastases in three patients (two SCCs, one MCC). No patient with negative SLN showed tumour dissemination during the follow-up over a mean of 2.5 years (range 2 months to 4.5 years, median 2.4 years).

CONCLUSIONS

Our data provide evidence that SLNE is a minimally invasive and highly sensitive staging tool in selected patients with high-risk nonmelanoma skin cancers.

Merkel cell carcinoma: a clinical, histopathologic, and immunohistochemical review

Merkel cell carcinoma is a rare aggressive neoplasm, with about 400 cases diagnosed in the United States each year. Among the cutaneous-derived neoplasms, it is the most deadliest, with a higher mortality rate than melanoma. Although the classic clinical presentation as a rapidly growing papule in a sun-exposed site of an elderly patient is not specific, certain histopathologic and ancillary pathologic features allow for its discrimination in most cases. Herein, we review the etiology, pathogenesis, clinical, and pathologic attributes as well as the staging treatment and prognosis of this important public health menace.

Merkel cell carcinoma--a retrospective analysis of 17 cases

OBJECTIVE

To report clinical experience with the rare neuroendocrine Merkel cell carcinoma of the skin.

SUBJECTS AND SETTING

Seventeen patients with Merkel cell carcinoma of the skin treated at the Departments of Dermatology and ENT, Krankenhaus Dresden-Friedrichstadt, Dresden, Germany, during the years 1984-2000 were evaluated.

METHODS

A retrospective analysis was performed. Age and sex distribution, clinical data and therapy were collected. Outcome measures including overall survival, tumour-free survival and relapse-free survival were determined.

RESULTS

Six male and 11 female patients with an age range of 68-90 years (mean age 73.3 years) were identified. The primary tumour localization was head and neck region (n = 8), upper limbs (8), lower limbs (1). Twelve patients presented in tumour stage I, three in stage II and one in stage III. First line therapy was complete surgical excision with wide margins in 16 patients followed by loco-regional radiation in 12 of 16 cases. In 16 patients follow up data were available. After primary treatment complete response was achieved in 14 of 16 patients (87.5%), two patients had a partial response. The median of relapse-free survival was 44 weeks [mean +/- standard deviation: (44 +/- 118) weeks]. The median of overall survival was 102 weeks [mean +/- standard deviation: (137 +/- 94) weeks]. Three patients with a PR after primary treatment had a median overall survival of only 48 weeks [mean +/- standard deviation: (51 +/- 20) weeks].

CONCLUSIONS

Primary surgical treatment with wide excision combined with radiotherapy seems to be a reasonable first-line treatment but prospective controlled multicentre trials are necessary for validation.

Imaging of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, highly malignant cutaneous tumor, primarily of the head and neck, that requires timely diagnosis, adequate staging, and aggressive therapy. MCC tends to be overlooked in the early stage, has a high propensity for invading local and regional nodal basins, and exhibits a high postoperative recurrence rate, with distant thoracic, abdominal, and central nervous system metastases. Conventional radiography and cross-sectional imaging show lesions similar to those originating from other small cell carcinomas. Nuclear medicine procedures such as sentinel node scintigraphy, somatostatin receptor scintigraphy, and positron emission tomography may be used to supplement judicious cross-sectional imaging evaluation, thereby adding diagnostic value in staging and providing therapeutic guidance. Ultimately, however, the diagnosis relies exclusively on pathologic findings at immunohistochemical staining and electron microscopy. The rarity of MCC and the resulting insufficient awareness of this neoplasm often delay correct identification and treatment, which essentially consists of wide-margin surgical excision of the primary tumor and local and regional radiation therapy. To date, clinical information is still insufficient to fully appreciate the role of imaging in MCC management. A better imaging algorithm is expected with increased awareness and improved clinical understanding of this uncommon skin neoplasm.

Is there a diminishing role for surgery for Merkel cell carcinoma of the skin? a review of current management

Merkel cell carcinoma is a highly malignant skin tumour that must be managed in a multidisciplinary forum. Excisional biopsy of the primary is recommended and this should be followed by postoperative radiotherapy to the primary site, in-transit areas and the draining lymph nodes. The tumour is quite radiosensitive and radiation doses of the order of 50 Gy offer high levels of local control. Resection margins of 3 cm are not required provided postoperative radiotherapy is used. In the event of inoperable disease, patient refusal of surgery or a frail patient, radiotherapy should be used as the sole treatment modality, with high likelihood of achieving local control. Patients with involved nodes have a higher risk of distant disease. Traditionally, involved nodes have been managed with resection but, currently, there are protocols exploring the use of synchronous chemoradiotherapy as definitive treatment. Although adjuvant chemotherapy has been used in this setting to reduce the risk of distant seeding, the benefits at this stage have not been confirmed conclusively. The presence of distant disease carries a grave outlook and responses to chemotherapy occur frequently, but are usually shortlived.

A meta-analysis of the prognostic significance of sentinel lymph node status in Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma is an aggressive cutaneous neoplasm with a high propensity to metastasize to lymph nodes.

OBJECTIVE

The objective of this study was to determine the prognostic significance of sentinel lymph node status in patients with Merkel cell carcinoma.

METHODS

A meta-analysis of case series of patients with Merkel cell carcinoma managed with sentinel lymph node biopsy was performed.

RESULTS

Forty of 60 patients (67%) had a biopsy-negative sentinel lymph node; 97% of this group had no recurrence at 7.3 months median follow-up. Twenty patients (33%) had a biopsy-positive sentinel lymph node; 33% of this group experienced local, regional, or systemic recurrence at 12 months median follow-up. Risk of recurrence or metastasis was 19-fold greater in biopsy-positive patients (odds ratio, 18.9; p = 0.005). None of 15 biopsy-positive patients who underwent therapeutic lymph node dissection experienced a regional recurrence; 3 of 4 who did not receive therapeutic lymphadenectomy experienced regional recurrence.

CONCLUSION

Sentinel lymph node positivity is strongly predictive of a high short-term risk of recurrence or metastasis in patients with Merkel cell carcinoma. Therapeutic lymph node dissection appears effective in preventing short-term regional nodal recurrence. Aggressive adjuvant treatment should be considered for patients with positive sentinel lymph nodes.