Desmoplastic melanoma: a challenge for the oncologist

Neurosarcomatous amelanotic transformation of malignant melanoma presenting as malignant periopheral nerve sheath tumor: Rare case report

RATIONALE

Malignant melanoma (MM) is notorious for its remarkable morphological variation and aberrant histopathological patterns. In addition, Malignant Periopheral Nerve Sheath Tumor (MPNST) is an uncommon but aggressive soft tissue sarcoma. Because of the common embryological origin of melanocytes and Schwann cells in the neural crest, discriminating between a particular type of MM and MPNST can be difficult, particularly when they are amelanotic. Our goal is to increase awareness among clinicians of the rare variations of MM and the importance of medical history in improving the accuracy of the final clinical diagnosis.

PATIENT CONCERNS

A 68-year-old man was admitted to the hospital due to pain in his right ankle, which had persisted for 8 months, along with swelling for 4 months. Medical history revealed delayed healing of right plantar for 5 years after a traumatic injury.

DIAGNOSES

The ankle mass was initially diagnosed as MPNST through biopsy. After reviewing the patient's medical history and receiving the final pathological report following amputation, we have revised the diagnosis to metastatic amelanotic desmoplastic melanoma in the ankle part and lentigo maligna melanoma in the plantar part. This is due to both lesions displaying positive markers or mutated genes in immunohistology and Gene Mutation Detection, indicating homology between the 2 tumors.

INTERVENTIONS

Due to the malignant characteristics of the tumor and the patient's wishes, amputation of the right lower leg was carried out.

OUTCOMES

Subsequently, the patient was treated with interferon-γ and immunosuppressant PD-1 inhibitor, and survived for 1 year after amputation.

LESSONS

Clinical data, immunohistochemisty biomarkers and genes detection results can serve as valuable evidence for pathologists and clinicians in identifying the disease process. Collaborative efforts between clinicians and scientists are crucial in order to identify specific markers that can effectively differentiate between the 2 tumors, thereby enhancing the conclusiveness of the diagnosis.

Desmoplastic Melanoma: Clinical Characteristics and Survival in the US Population

Objective

Desmoplastic melanoma (DM) is a rare variant of invasive malignancy of the skin pigmented cells. We present a comprehensive study reporting on US demographics, disease characteristics, and survival, to contribute to the current knowledge and raise awareness of this rare disease.

Materials and methods

The demographics of DM patients diagnosed from January 1, 2004, to December 31, 2015, were obtained by querying the National Cancer Database. The characteristics of DM were compared with common malignant melanoma (CMM) using univariate and multivariate regression models. Five-year overall survival (OS) curves were estimated using Kaplan-Meier analyses and the Cox proportional regression model.

Results

Our query found 5,895 patients diagnosed with DM and 292,939 patients with CMM. DM tended to present at an older age, a more advanced stage, and with a Breslow depth greater than 4 mm at diagnosis (P<.05). The Kaplan-Meier survival analysis demonstrated a five-year OS for DM and CMM of 75% and 76%, respectively, without any statistical difference (P=.07). Cox regression analysis demonstrated that age at diagnosis and comorbidities were independent predictors of five-year OS for DM (P<.001).

Conclusions

Older age, advanced stage, and higher Breslow depth were found to be independent positive factors associated with DM.

Desmoplastic melanoma: Demographic and clinicopathological features and disease-specific prognostic factors

Desmoplastic melanoma (DM) is a rare morphological subtype of melanoma that remains uncharacterized. The aim of the present study was to investigate the incidence of DM, its general demographics, clinicopathological features and disease-specific prognostic factors. DM cases were sampled from the Surveillance, Epidemiology and End Results (SEER) program from between 1973 and 2017. A total of 3,657 cases (median age, 68 years) were identified. The results indicated that DM primarily occurred in Caucasian subjects, with a male-to-female ratio of 2:1. Statistically significant overall survival (OS) and disease-specific survival (DSS) rate differences were identified according to sex, age, treatment, T stage, N stage and SEER historic tumor stage (P<0.05). In multivariate Cox regression analysis, age >68 years, male sex, American Joint Committee on Cancer (AJCC) stage II and III, and SEER historic tumor stage of the regional tumor were all factors associated with poorer OS and DSS rates. The findings also revealed that surgical treatment was associated with favorable DSS and OS rates. In conclusion, DM occurred primarily in Caucasian subjects of 60–80 years of age, with predominance in males. Furthermore, age, sex, AJCC stage, SEER historic tumor stage and surgical treatment were identified as independent prognostic factors of DM in terms of DSS and OS.

Reflectance confocal microscopy in the diagnosis of pigmented macules of the face: differential diagnosis and margin definition

Here we review the state-of-the-art of RCM morphologic descriptors, standardized terminology, and diagnostic algorithms for the assessment of pigmented macules of the face, for their correct diagnosis and management.

Desmoplastic melanoma versus spindle cell melanoma: Incidence and survival, 1973 to 2017

Desmoplastic melanoma (DM) and spindle cell melanoma (SCM) are 2 rare subtypes of melanoma. This study aims to investigate these 2 melanomas comprehensively by comparison.Cases were identified in the Surveillance, Epidemiology, and End Results (SEER) database (1973-2017).A total of 3657 DM and 4761 SCM cases were identified. DM's female-to-male ratio was 1:2 and SCM's was 0.62:1. The age distribution was similar. Both tumor mostly originated from skin and the eye and orbit was SCM-specific tumor site. Comparing both tumors with DM as reference, significant overall survival (OS) were found depending on sex (women, P < .001), age (age ≤65 years, P < .001), race (white, P = .01), tumor orientation (skin, P < .001), T stage (T3 + T4, P = .001), SEER historic stage (regional tumor, P = .04), and surgery (P = .01). Meanwhile, significant disease specific survival (DSS) differences were found depending on sex (men, P < .001), age (age ≤65 years, P < .001), race (white, P < .001), tumor orientation (skin, P < .001), T early stage (T1 + T2, P = .02), T advanced stage (T3 + T4 stage, P = .001), SEER historic stage (regional tumor, P < .001), and surgery (P < .001). The chance of DSS and OS of SCM were significantly higher comparing to DM for female patients (HR = 1.268, for OS; HR = 1.711, for DSS), patients age ≤65 years (HR = 1.290, for OS; HR = 1.638, for DSS), No-Spanish-Hispanic-Latino patients (HR = 1.098, for OS; HR = 1.426, for DSS), patients with skin tumor (HR = 1.174; for OS; HR = 1.444; for DSS) and patients who received surgery (HR = 1.091; for OS; HR = 1.398, for DSS).DM and SCM mostly occurred in white people' skin at 60 to 80 years old and eye and orbit was another most affected site for SCM. SCM had slightly higher occurrence in women and the risk of DSS and OS were significantly higher comparing to DM depending on the women, patients age ≤65 years, patients with skin tumor, No-Spanish-Hispanic-Latino patients and patients who received surgery.