Bone marrow metastasis of malignant melanoma in childhood arising within a congenital melanocytic nevus

Bone marrow metastases: a systematic review of a neglected involvement in malignant melanoma

The occurrence of bone marrow metastases (BMM) in melanoma patients is often underestimated, with only 7% detected during in-vivo staging procedures but rising to 45% in autopsy cases. This systematic review aims to shed light on the clinical and laboratory features of BMM in melanoma by analyzing 73 studies selected from 2 482 initially retrieved from PubMed, Embase , and Cochrane CENTRAL databases. Our findings reveal a slight male predominance, with a median age at BMM diagnosis of 56 years. Primary melanoma sites included the skin (52%), mucosa (8.8%), uvea (20.5%) and unidentified (19%). BMM was preceded by lymph node involvement in 36.5% of cases, whereas 63% showed no nodal metastases, with direct BMM occurring in 22.5% and metastases to other sites in 41%. Common BMM symptoms included pain (60.7%), anemia (80%), thrombocytopenia, leukoerythroblastosis, pancytopenia and leukopenia, while disseminated intravascular coagulation was detected in 11% of cases. In 23.6% of cases, BMM was amelanotic. The prognosis for BMM is grim, with a median survival of only 2 months. Conventional therapies for BMM remain largely ineffective, emphasizing the importance of considering bone marrow as a potential metastatic site in melanoma patients.

Melanoma in children: A systematic review and individual patient meta-analysis

The current evidence on paediatric melanoma is heterogeneous, especially regarding the prognosis of different histological subtypes. We sought to systematically review the evidence on paediatric melanoma, highlighting the major sources of heterogeneity and focusing on available data on single patients. A systematic search was performed from 1948 to 25 January 2021. Only studies reporting at least one case of cutaneous melanoma in patients aged ≤18 years were included. Unknown primary and uncertain malignant melanomas were excluded. Three couples of authors independently performed title/abstract screening and two different authors reviewed all the relevant full texts. The selected articles were manually cross-checked for overlapping data for qualitative synthesis. Subsequently data on single patients were extracted to perform a patient-level meta-analysis. PROSPERO registration number: CRD42021233248. The main outcomes were melanoma-specific survival (MSS) and progression-free survival (PFS) outcomes. Separate analyses were done of cases with complete information on histologic subtype, focusing on superficial spreading (SSM), nodular (NM) and spitzoid melanomas, as well as of those classified as de-novo (DNM) and acquired or congenital nevus-associated melanomas (NAM). The qualitative synthesis covered 266 studies; however, data on single patients were available from 213 studies including 1002 patients. Among histologic subtypes, NM had a lower MSS than both SSM and spitzoid melanoma, and a lower PFS than SSM. Spitzoid melanoma had a significantly higher progression risk than SSM and trended toward lower mortality. Focusing on nevus-associated status, DNM demonstrated better MSS after progression than congenital NAM, and no differences were highlighted in PFS. Our findings describe the existence of different biological patterns in paediatric melanoma. Specifically, spitzoid melanomas demonstrated intermediate behaviour between SSM and NM and showed a high risk of nodal progression but low mortality. This raises the question of whether spitzoid lesions are being over-diagnosed as melanoma in childhood.

Effective Immunotherapy in Bone Marrow Metastatic Melanoma Presenting with Disseminated Intravascular Coagulopathy

Malignant melanoma is responsible for the majority of skin cancer deaths and is increasing in prevalence. Bone marrow (BM) involvement by melanoma is rare in the absence of widespread visceral disease. Here, we report the case of a 30-year-old female who presented to the hospital with back pain, low-grade fever, and easy bruising. She was found to be bicytopenic and in disseminated intravascular coagulopathy (DIC). Surprisingly, BM biopsy showed extensive involvement by metastatic malignant melanoma in the absence of visceral or brain metastasis. The unique presentation of this case and the challenge of management of a potentially treatable cancer in a critically ill patient are discussed, alongside a review of published cases of metastatic melanoma in the BM and an exploration of currently available treatment options. The excellent response of our patient to combined immune checkpoint inhibitors has yet to be paralleled in the available literature.