A clinicopathologic study of malignant melanoma based on cytomorphology

BRAF V600E Mutations and Beyond: A Molecular Perspective of Melanoma from a Tertiary Cancer Referral Center of India

Vaibhavi VengurlekarObjectives  Malignant melanoma demonstrates frequently occurring mutations of genes in the serine/threonine kinase pathway, namely BRAF, NRAS, and neurofibromin 1. There is rare documentation of a detailed analysis of these mutations in cases of melanoma among Indian patients. We present molecular features in cases of malignant melanoma, diagnosed at a tertiary cancer referral center in India, over a period of 8 years (2011-2018). Materials and Methods  This study was performed on formalin fixed paraffin embedded tissues of 88 histologically confirmed cases of malignant melanoma. BRAF gene alterations were studied by both Sanger sequencing and real-time polymerase chain reaction techniques ( n  = 74). Molecular testing for BRAF and NRAS gene alterations was accomplished in 74/88 cases (80%). Molecular test results were correlated with clinicopathological features using IBM SPSS Statistical software 25.0. Results  The age ranged from 13 to 79 years (median = 57), with a M:F ratio of 1.4:1. BRAF mutations were observed in 12/74 (16.21%) patients, including V600E ( n  = 7), A594T ( n  = 1), T599 = ( n  = 2), V600K ( n  = 1), and Q612P ( n  = 1), while NRAS mutations were observed in 6/38 (15.7%) patients. Among various subtypes, nodular melanoma was the most frequent subtype (33%) among cutaneous malignant melanomas. Among non-cutaneous melanomas, mucosal melanomas were observed in 37.5% of cases. Conclusion  This constitutes one of the few reports on comprehensive analysis of molecular alterations underlying melanomas in Indian patients. A larger sample size, with more extensive molecular markers, would yield additional information on the disease manifestation.

Histopathologic and Molecular Features of Cutaneous Melanoma in a Moroccan Population

Background Cutaneous cancer is the most common malignancy type, among which melanomas are considered the most aggressive and lethal. In Morocco, skin melanoma is the 25th most common cancer. To our knowledge, this is the first and largest Moroccan study specifically describing cutaneous melanoma.  Materials and methods We obtained data for 100 patients diagnosed with cutaneous melanoma in the Department of Pathology of Hassan II University Hospital, Morocco. Clinical, histopathological, molecular, and follow-up data were recorded from pathology request forms and the patient's medical records.  Results The mean age of our patients was 65 years old. Histologically, the most prevalent were the nodular (48%) and acro-lentiginous (38%) melanoma subtypes. A total of 66% of the patients had a Breslow thickness of >4 mm. The presence of ulceration was noted in 46% of cases. The average mitoses was 9/1 mm². A total of 44% of patients had metastatic melanoma at the time of diagnosis. The BRAF V600E mutation was found in six cases, and the C-KIT mutation in five cases. The five-year overall survival and metastasis-free survival were 85% and 15%, respectively. There was a significant correlation between Breslow thickness and Clark's level (p<0.001), histologic subtype (p=0.012), and presence of metastasis (p=0.002). There was a significant difference between the head and neck melanomas and those of the feet, particularly in the histological subtype and the presence of ulceration. BRAF V600E mutation was found in six cases of metastatic melanomas of the head and neck, of which three cases were positive for this mutation, as compared with the 23 cases of acral melanomas, which tested negative for the same mutation.  Conclusion The results of our study showed that cutaneous melanomas were characterized by advanced age at diagnosis and late-stage diagnosis with a high Breslow index. The lower limbs were the most affected sites, especially in the plantar region. The acral lentiginous subtype was the most common. The presence of BRAF V600E mutation was associated with a better prognosis.

Clinicopathological Profile of a Cohort of Patients With Malignant Melanoma in the United Kingdom

Introduction Malignant melanoma (MM) is potentially a fatal type of skin cancer and a major health concern for the Caucasian population. It is a heterogeneous disease with a wide spectrum of manifestations. Therefore, in this study, we evaluated the clinicopathological characteristics of MM. Methods We retrospectively studied the clinicopathological characteristics of MM in 167 biopsy-proven cases of MM reported between January 2020 and December 2021 at Kings Mill Hospital, Sutton-in-Ashfield, United Kingdom. Clinical data such as the age, sex, and anatomical site of the lesion were obtained from the clinical referral forms. Biopsies of the lesions were performed, and the specimens collected were sent to the laboratory for histopathological study and v-raf murine sarcoma viral oncogene homolog B1 (BRAF) mutation evaluation. Formalin-fixed paraffin-embedded blocks (FFPE) were prepared, sectioned, and stained with hematoxylin and eosin for histological examination. Results A total of 167 cases of MM were included in the study. The age range was 23-96 years, with the median age at diagnosis found to be 66 years; males were more commonly affected (52.1%). The median Breslow thickness was 1.20 mm. The median mitotic activity was 1.0/mm². The lower limb was the most common site of involvement (27.5%), followed by the thorax (25.1%). The most common histological subtype was superficial spreading melanoma (SSM) (77.8%), followed by nodular melanoma (14.4%). The in situ component was present in 95.8% of cases; a majority (92.2%) of the cases showed vertical growth phase, 71.9% of cases were at Clark's level IV of invasion, regression was noted in 70.7% of cases, ulceration was present in 21.6% of cases, and microsatellites were present in 3% of cases. Perineural invasion was present in 3% of cases, and lymphovascular invasion (LVI) was present in 4.2% of cases. BRAF mutation testing was performed on 36 cases, out of which 20 cases (55.6%) showed BRAF mutation. Acral lentiginous melanoma and nodular melanoma were most likely to show ulceration (66.7% and 37.5%, respectively). SSM and lentigo maligna melanoma were more likely to be associated with regression. Conclusion The study demonstrated that MM is prevalent among the elderly population with male predominance; SSM was found to be the most common subtype. The study further demonstrated various clinicopathological features of MM and its association with histological subtypes.

Early Experience with Dabrafenib–Trametinib Combination in Patients with BRAF-Mutated Malignant Melanoma—A Single-Center Experience

Background Combination of dabrafenib–trametinib is one of the standard treatments in patients with BRAF-mutated advanced malignant melanoma (MM). Real-world data on the usage of this combination is scarce, especially from India. Here, we are reporting our early experience with the usage of this combination therapy.

Materials and Methods This is a single institutional data assessment of patients with BRAF-mutated MM registered and treated with BRAF–MEK inhibitors in our hospital. Clinico-pathological features and treatment details were reviewed for all patients.

Results A total of seven patients with BRAF-mutated MM treated with this combination therapy with a median age of 66.5 years (range: 49–72 years) and a male:female ratio of 3:4. Six (85.7%) patients had metastatic disease at presentation. In total, 80% of our patient population had two or less than two sites of metastasis at presentation. The initial response rate of the study population was 71%. The drug was well tolerated with fever being the most common side effect which was seen in two (28.5%) of the patients.

Conclusion Combination of dabrafenib–trametinib is effective in patients with BRAF-mutated MM with good tolerability. Further studies are required to look for improvement in outcome in this group of patients.

Rhabdoid melanoma: A diagnostic ordeal

A 64-year-old man presented with multiple, bilateral pulmonary nodules, considered clinically to be intrapulmonary metastasis from lung carcinoma. On histopathologic examination, a tumor with a solid growth pattern and rhabdoid neoplastic morphology was seen. Initially, a diagnosis of nonsmall cell carcinoma of lung was considered but the immunophenotype was not supportive. Further, extensive immunohistochemistry revealed SOX10, Melan-A, and HMB45 expression in the absence of S-100. Strong globular cytoplasmic staining for vimentin, SMA, Desmin, and WT1 were observed. A final diagnosis of rhabdoid melanoma was made. The immunoprofile of our case was unique from previously described rhabdoid melanoma in English literature. The globular staining for intermediate filaments such as desmin and SMA is a novel finding. The strong WT1 intracytoplasmic staining reported previously was also observed in this case, with intense globular characteristics.

Clinicopathological study of malignant melanoma in a regional cancer center

BACKGROUND

: Malignant melanoma is a tumor of melanocytic origin. Although uncommon in India as compared with the west, its prevalence is increasing.

OBJECTIVES

To document the pattern of clinicopathological features of malignant melanoma cases attending in a regional cancer center in eastern India.

MATERIAL AND METHODS

The present study was a retrospective study of 182 cases diagnosed histopathologically as malignant melanoma during 2011-2016.

RESULTS

Out of the total cases, 170 (93.4%) were cutaneous and 12 (6.6%) were noncutaneous melanoma. The most common age group was sixth decade with a male predominance. Conventional melanotic melanomas were 176 (96.70%), and only 6 cases (3.30%) were amelanotic melanoma. Among noncutaneous melanomas, 6 were in anorectum, 2 in conjunctiva, and 1 case each in nasal cavity, palate, gingivo-buccal sulcus, and vagina. The acrallentigenous type was the most common variety, and the mixed epithelioid and spindle cell type was the most common histopathological pattern. Clark's level III was the most common level of invasion.

CONCLUSION

The lower extremity is the most common site for melanoma, whereas extracutaneous melanomas are exceedingly rare and aggressive neoplasms. Melanoma can metastasize to regional lymph nodes, however, visceral metastasis to liver can also occur. In the absence of pigment in amelanotic melanoma, immunohistochemical markers such as HMB 45 can be used for definitive diagnosis.