Melanoma predilection for the lower limbs of women compared with men.

The lower limb is a common site for melanoma in women, but the reason for this is not fully understood. To investigate this phenomenon in more detail, we assessed the specific subsites of primary melanoma occurring on the lower limbs of females compared with males across age groups. In a records-based study at an oncology hospital in north-west of England, among an unselected sample of patients with primary invasive melanoma treated between 2002-2015, information was collected on patient age at diagnosis, sex, and co-morbidities, and the tumor thickness and anatomical subsite (thigh, lower leg, foot for lower limb). Of a total sample of 1,522 patients, 316 (227, 72% female) had lower limb melanoma. The most common subsite was lower leg (142 cases with F:M ratio =3.74), followed by thigh (55 cases with F:M = 1.83) and feet (30 cases with F:M = 1.15). At ages <40 years the odds of thigh to foot melanoma was 20 times higher in females than in males (OR 20.0, 95% CI 2.6-152.6) and 7.5 times higher on the lower limb (OR 7.5, 95% CI 1.1-49.2). For ages 40+ years, the odds of females developing thigh melanoma compared to foot melanoma was similar in males versus females (OR 0.8), while the corresponding odds of lower leg melanoma in females versus males remained significantly increased at ages 40-59 and 60+ (OR 4.2 and 2.8 respectively). Our study demonstrates the female predilection for lower limb melanoma persists over most but not all subsites.However, there is heterogeneity in the female to male occurence of lower limb melanoma across subsites and at different ages, which may be linked to relative influence of genetic and environmental risk factors.

Pathology of sentinel lymph nodes for melanoma.

As a concept sentinel lymph node biopsy seems attractive in that it attempts to identify the first lymph node, rather than the nearest node, draining a particular anatomic area where a tumour has arisen. Pathological assessment can then indicate whether metastases are present and the procedure is either a strong prognostic indicator or possibly therapeutic in itself. These comments apply to any tumour type, but with melanoma the pathological procedure is more problematic and any benefits above prognosis and staging are not universally accepted. The procedure does give accurate staging without the extra morbidity of regional node dissection and many patients gain psychological support from the information gained.

The correlation of regression in primary melanoma with sentinel lymph node status.

BACKGROUND: The significance of regression in primary melanoma has been disputed for many years. Some have suggested regression as a marker for poor prognosis while others have reported a negligible or even a favourable effect, on prognosis. AIM: To understand the significance of regression in melanoma and provide further information on whether patients should be subjected to sentinel lymph node biopsy (SLNB) on the basis of regression. METHODS: 146 melanoma cases who had undergone SLNB were included in the study. The histological criteria for offering SLNB were melanoma >1 mm in thickness, Clark's level IV or those with regression. RESULTS: A statistically significant greater proportion of individuals without regression showed sentinel lymph node (SLN) positivity (p = 0.028) compared with those which do show regression. Metastatic disease correlated with growth phase of the primary lesion. All the node positive cases were in the vertical growth phase; none of the cases in radial growth phase and showing regression were associated with nodal metastasis (p = 0.029). 62 cases had melanomas with thickness <1 mm and were in radial growth phase, yet were offered SLNB because of regression. Of these, 44 showed features of regression and all were node negative. The remaining 16 cases of thin melanomas did not show regression; 2 of these had sentinel node metastasis. CONCLUSION: Results suggest that regression is usually a favourable process, particularly in thin melanomas and that metastasis in "thin melanomas showing regression" is real but rare. Variant vertical growth phase, mitoses and other prognostically significant variables may be more important predictors of metastatic potential in thin melanomas.

The role of sentinel node biopsy in the management of melanocytic lesions of uncertain malignant potential (MUMP).

Melanocytic lesions of uncertain malignant potential (MUMP) is a term which is useful in identifying melanocytic tumours where the distinction between benign and malignant is a histological problem. Sentinel node biopsy is recognised to provide unmatched prognostic information in melanoma patients, but has recently been advocated for diagnostic purposes in MUMP. We present the case of a seven-year-old girl who presented with a six-month history of a changing pigmented lesion on her left upper arm. Excision biopsy not only showed a melanocytic lesion with some spitzoid features but also marked atypia making it appropriate to use the term MUMP. Sentinel node biopsy was undertaken. This case demonstrates that sentinel node biopsy can be performed safely in children. Given the low morbidity of the procedure we advocate that this technique should be considered in this difficult diagnostic situation to further the management of these patients.

Features of sentinel lymph nodes for melanoma may lead to re-diagnosis of the cutaneous primary: an unusual case and review of literature.

Although sentinel lymph-node biopsy is accepted as a reliable method of staging of melanoma, it is not without problems to the pathologist. It has been re-emphasised that aggregates of benign naevus cells are not uncommon. Usually these are easily identified by a combination of their benign cytology and location in the fibrous skeleton of lymph nodes. This case represents a combination of an unusual pseudo-malignant pattern in the primary lesion with unusual morphology of the sentinel lymph node. The latter prompted reassessment of the cutaneous lesion as a benign naevus. Confirmation of the diagnosis as cutaneous melanoma by a positive sentinel-node biopsy was averted only by a careful comparison of unusual features of the putative primary and the sentinel lymph node. This case illustrates the need for a rigorous protocol for pathological assessment of sentinel lymph nodes for melanomas to assure detection of all metastases but also to avoid misdiagnosis and over-treatment. It also supports "benign metastases" as the mechanism underlying at least some melanocytes in regional lymph nodes.

The microanatomic location of metastatic melanoma in sentinel lymph nodes predicts nonsentinel lymph node involvement.

PURPOSE: Sentinel node biopsy is now widely accepted as the most accurate prognostic indicator in melanoma, and is important in guiding management of patients with clinical stage I or II disease. Patients with a positive sentinel node have conventionally undergone completion lymphadenectomy (CLND) of the involved basin, but only 20% have involvement beyond the sentinel node, suggesting that CLND may be unnecessary for the other 80% of patients. This study seeks to identify criteria that might be used to be more restrictive in selecting those who should undergo CLND. METHODS: A total of 146 patients were identified who had had a positive sentinel node biopsy for malignant melanoma. Their sentinel nodes and lymphadenectomy specimens were re-evaluated pathologically. The metastatic melanoma in each sentinel node was assessed according to its microanatomic location within the node (subcapsular, combined subcapsular and parenchymal, parenchymal, multifocal, or extensive), and this was correlated with the presence of involved nonsentinel nodes in the CLND. The depth of the metastases from the sentinel node capsule was also recorded. RESULTS: The metastatic deposits in the sentinel node were subcapsular in 26.0% of patients. None of these patients had any nonsentinel nodes involved on CLND. In the patients whose sentinel node metastases had a different microanatomic location, the rate of nonsentinel node involvement was 22.2% overall. CONCLUSION: The microanatomic location of metastases within sentinel nodes predicts nonsentinel lymph node involvement. In patients with only subcapsular deposits in the sentinel node, it is possible that CLND could safely be avoided.

Interobserver reproducibility of ulceration assessment in primary cutaneous melanomas.

In the recently revised melanoma staging system proposed by the American Joint Committee on Cancer (AJCC), ulceration assessment by the pathologist is a pivotal parameter. Patients upstaged because of ulceration might be included in adjuvant trials conducted in AJCC stage II melanoma patients. Therefore, accuracy based on interobserver reproducibility for melanoma ulceration assessment is crucial for proper clinical management. In some cases, it is extremely difficult, even for an experienced pathologist, to distinguish between trauma-induced ulceration, artifact and tumoral ulceration. Whether this difficulty may be resolved by the use of a more precise definition of ulceration has not been evaluated. Therefore, we have proposed a refined definition of melanoma ulceration and we tested whether this definition might improve the interobserver interpretative reproducibility of ulceration in primary cutaneous melanomas. The results of this study support the need for a more precise definition of melanoma ulceration that rules out biopsy trauma or processing artifact and could be incorporated into a standardised pathology worksheet for reporting primary melanomas.

Halo naevus or malignant melanoma? A case report.

It is generally felt that a halo naevus is benign, and patients can be reassured. The lesion is frequently left alone. We present a case where the clinician felt reassured, but at the patient's insistence the lesion was excised. The histology result was not anticipated.

Microstaging in cutaneous melanoma.

Recent papers have addressed critical issues regarding the microstaging of cutaneous melanoma. They concern the new staging proposal by the American Joint Committee on Cancer (AJCC), the presentation of new prognostic models than seem applicable in daily practice, and new immunohistochemical findings than demonstrate prognostic information independently of the conventional major factors. These issues are commented on by the Pathology Committee of the EORTC Melanoma Group.

Sentinel lymph node biopsy in malignant melanoma: a series of 100 consecutive patients.

A consecutive cohort of 100 patients who had undergone sentinel lymph node biopsy (SLNB) was analysed retrospectively. Three areas were studied: success in finding the sentinel node(s); complications of the procedure; and extra costs incurred by SLNB. The sentinel node(s) were successfully identified in 98% of the lymph node basins biopsied. The overall complication rate was 33%. The additional cost of the procedure was estimated at 1420 pounds sterling per patient. SLNB can reliably identify the sentinel node. However there is a significant complication rate of the technique and considerable additional costs. SLNB requires further critical evaluation before it can be accepted as a standard treatment for patients with malignant melanoma.

Melanoma yield, number of biopsies and missed melanomas in a British teaching hospital pigmented lesion clinic: a 9-year retrospective study.

The demand for pigmented lesion clinics (PLCs) is increasing in view of improved skin cancer awareness following public health education campaigns. These clinics offer an effective way of screening a large number of patients. However, there is no evidence, as yet, that they have an impact on mortality due to malignant melanoma. With the lack of follow-up inherent to these busy screening clinics, there is some concern that melanomas may be missed. This study reports on 7874 patient visits to a PLC in a teaching hospital between 1985 and 1994. In total, 1705 biopsies were performed over the 9-year period. Lesions were more likely to be biopsied in men compared with women. The yield for picking melanomas was one in 36 patient visits. The mean age of patients attending the PLC was 10 years less than the mean age for population-based melanomas. Melanoma thickness did not significantly change over the 9-year period. Only 0.2% of patients (14 cases) re-presented to the PLC for a second or third visit with a final diagnosis of melanoma, but for five of these patients, the interval between the two visits was over 2 years. Most of these 're-attending' melanomas were early lesions. PLCs offer a fast, safe and efficient service for the screening of pigmented lesions but their role in reducing mortality due to malignant melanoma remains to be established. It is likely that these clinics have an important role in terms of public health education regarding sun avoidance and early recognition of skin cancer.

Extensive naevoid eccrine spiradenoma.

We describe a 19-year-old girl with a painful naevoid eccrine spiradenoma affecting the right side of the body. This represents an extremely rare variant of this benign eccrine sweat gland tumour, and is the most extensive lesion described in the U.K. to date.

An assessment of the operation of an external quality assessment (EQA) scheme in histopathology in the South Thames (West) region: 1995-1998.

AIMS: To describe the design and organisation of a voluntary regional external quality assessment (EQA) scheme in histopathology, and to record the results obtained over a three year period. METHODS: A protocol is presented in which circulation of EQA slides alternated with teaching sessions. Procedures for the choice of suitable cases, evaluation of submitted diagnoses, and feedback of results to participants are described. The use of teaching sessions, complementary to the slide circulations, and dealing with current diagnostic problems is also outlined. RESULTS: Participation rates in the nine slide circulations varied between 66% and 89%, mean 85%. Overall scores were predictably high but 4% of returns, from 10 pathologists, were unsatisfactory. These low scores were typically isolated or intermittent and none of the participants fulfilled agreed criteria for chronic poor performers. CONCLUSIONS: This scheme has been well supported and overall performances have been satisfactory. The design was sufficiently discriminatory to reveal a few low scores which are analysed in detail. Prompt feedback of results to participants with identification of all "incomplete" and "wrong" diagnoses is essential. Involvement of local histopathologists in designing, running, and monitoring such schemes is important.

Atypical dermal nodules in benign melanocytic naevi.

AIMS: The prognosis of deeply invasive melanoma can be poor and to a large extent it is unresponsive to treatment once metastases have occurred. It is therefore important that any dermal melanocytic lesions that have some features suggestive of melanoma but are nevertheless benign, should be identified. METHODS AND RESULTS: A series of 40 benign melanocytic naevi is described in which the clinical presenting feature was a central focus of increased pigmentation. This was found histologically to correspond to dermal nodules of large melanocytes showing some, usually mild, nuclear atypia but low indices of cellular proliferation. The nodules are found within otherwise typical melanocytic naevi. The clinical and histological differential diagnosis included invasive melanoma but in follow-up, which is admittedly short (mean 24 months), none have recurred or metastasized. CONCLUSIONS: It is suggested that the nodules represent terminal differentiation of melanocytes rather than proliferative changes. They should be distinguished from melanoma and regarded as a variant of benign melanocytic naevi.