Liver Metastases from Melanoma Cancer

Stage

Depth

Less or equal to 0.75 mm

0.75–1.5 mm

III

1.51–2.25 mm

2.26–3.0 mm

Greater than 3.0 mm

Table 6.2

Clark’s levels

Level	Depth
I	Melanoma confined to the epidermis
2	Invasion into the papillary dermis
3	Invasion into the junction of the papillary and reticular dermis
4	Invasion into the reticular dermis
5	Invasion into the subcutaneous fat

Table 6.3

AJCC staging

Primary tumor
Tx	Primary cannot be assessed
T0	No evidence of primary tumor
Tis	Melanoma in situ
T1	≤1 mm thick
T2	1.01–2.0 mm thick
T3	2.01–4.0 mm thick
T4	>4.0 mm thick

Regional lymph nodes
Nx	Regional nodes cannot be assessed
N0	No regional metastases detected
N1	Single regional node	a – micrometastasis
N1	Single regional node	b – macrometastasis
N2	2–3 nodes	a – micrometastasis
		b – macrometastasis
		c – in transit metastasis without lymph nodes
N3	4 or more metastatic nodes or matted nodes or in transit metastasis with metastatic nodes

Distant metastasis	Site of metastasis	LDH
M0	No detectable evidence of distant metastasis
M1a	Skin, subcutaneous, or nodal metastasis	Normal
M1b	Lung	Normal
M1c	All other visceral metastases	Normal
M1c	Any distant metastasis	Elevated

Clinical staging
Stage 0	T1s	N0	M0
Stage IA	T1a	N0	M0
Stage IB	T1b	N0	M0
Stage IB	T2a	N0	M0
Stage IIA	T2b	N0	M0
Stage IIA	T3a	N0	M0
Stage IIB	T3b	N0	M0
Stage IIB	T4a	N0	M0
Stage IIC	T4b	N0	M0
Stage III	Any T	≥N1	M0
Stage IV	Any T	Any N	Any M

a without ulceration, b with ulcerations

Intra-abdominal metastases are common in patients with melanoma. In the vast majority of patients, the disease is disseminated, and of those patients undergoing surgery, two thirds are treatable with intention for complete extirpation of the tumor [3]. The liver is a very common site for metastases from melanoma. Approximately 3 % of all patients have metastases to the liver. Cutaneous melanomas metastasized to the liver in up to 20 % of those patients with metastatic disease. The incidence of hepatic metastases is much more common in patients with ocular melanomas, with up to 40 % of patients having liver metastases at the time of diagnosis [4]. The liver is involved with metastasis from ocular melanoma in over 90 % of cases. Despite the high frequency of metastatic disease, the pattern of disease and associated extrahepatic disease means that only a very small proportion of patients are suitable for surgical treatment [5].

6.3 Surveillance for Metastatic Disease

Follow-up of patients after resection of primary melanomas is related to the depth of invasion of the lesion. For patients with lesions that are less than 1 mm, the risk of recurrence is quite small, and as such if they do not have specific risk factors for the development of a second melanoma, then close follow-up is not necessary. They should have yearly skin checks for 2–3 years, and then review as necessary depending on clinical symptoms. For patients with melanomas thicker than 1 mm, clinical examination of the locoregional lymph nodes, and a complete skin examination, is necessary. As the thickness of the melanoma increases, the frequency of recurrence increases, and more extensive investigations may be required.

In patients with melanomas greater than 4 mm thick serum LDH, staging investigations looking for metastatic disease are required at presentation. There is no evidence that routine surveillance imaging confers a survival benefit, even if metastases are detected earlier, then clinical symptoms arise. In patients where symptoms are present, axial CT scanning and magnetic resonance imaging are appropriate initial investigations. Where there is a high suspicion of recurrence, 18 fluorodeoxyglucose positron emission tomography scan is the most appropriate investigation.

6.4 Staging of Recurrence

When metastatic liver disease is detected, all appropriate clinical and pathological staging investigation should be undertaken. The patients require a serum lactate dehydrogenase level, as well as an axial CT scan of their head, neck, chest, and abdomen. Patients affected by metastases should also undergo an 18 FDG PET scan.

6.5 LDH

Lactate dehydrogenase is secreted when melanoma cells outgrow their vascular supply. It is the strongest independent prognostic factor in metastatic melanoma, and it predicts a poorer survival and a reduction in response to treatment. This is independent of the volume of metastatic disease present. Due to the potential false-positive values for lactate dehydrogenase, it is advised that more than one sample is obtained when using it as a prognostic marker [6].

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