The study involves enrollment of patients with sebaceous carcinoma, Merkel's carcinoma, Porocarcinoma, Melanoma, and squamous cell Ca of the ocular surface and adnexa both primary and relapsed after surgical and/or radiation-chemotherapy treatment at the Fondazione Policlinico Universitario A. Gemelli, IRCCS. The study will last 9 years: 1 year will be devoted to the first phase of the study. Patient enrollment will continue for an additional 3 years, and 5 years will be devoted overall to patient follow-up so that survival outcomes at 1-3 and 5 years can be assessed in a congruent number of patients. A preliminary analysis of the data at 1 year (pilot phase), an analysis at 4 years to confirm the preliminary study data on a larger sample, and a final analysis to evaluate OS and PFS at the 3 time-points indicated are planned.

Patients will undergo:

• Evaluation in the ocular oncology outpatient clinic with examination and anterior segment photography
• Staging according to TNM AJCC 8th edition by incisional biopsy (if necessary after clinical evaluation) and/or excisional biopsy and imaging to be performed in current clinical practice (MRI with mdc orbits, massif and neck + Tc/Pet total body)
• Injection of 99mTc-labeled nanocolloids
• Preoperative lymphoscintigraphy
• Intraoperative search by gamma probe of the sentinel lymph node
• Sentinel lymph node biopsy
• Excisional biopsy of the neoformation in cases not undergoing excision before SLN biopsy.
• In case of SLN histologic positivity, the multidisciplinary team will consider whether to refer the patient for parotidectomy and excision of the lymph node chain and/or adjuvant radio/chemotherapy.
• Clinical-instrumental follow-up to be performed in current clinical practice (Clinical examination, cranial orbit and neck MRI, total body CT scan) at 3, 6, 12, 18, 24, 36, 48, 60 months or according to periodicity assessed on a case-by-case basis by the Tumor Board.

Inclusion Criteria:

• All patients with Porocarcinoma, Ca of Merkel, Ca Sebaceous
• Patients with cutaneous adnexal melanoma with thickness ≥1.5 mm, Clark's level ≥3, >1 mitotic figure per high-power field.
• Patients with conjunctival melanoma both primary and recurrent and associated with primary acquired melanosis with atypia.
• Patients with squamous cell Ca of adnexa with Staging ≥3, locally recurrent or with perineural invasion
• Patients with squamous cell Ca of the surface with Staging ≥3 and/or multicenter
• Signature of informed consent to participate in the study
• cNo

Exclusion Criteria:

• Age less than 18 years
• Patients with metastatic disease at diagnosis
• All patients who do not fit the inclusion criteria
• Failure to obtain informed consent

Patients with sebaceous carcinoma, Merkel's carcinoma, Porocarcinoma, Melanoma, and squamous cell Ca of the ocular surface and adnexa both primary and relapsed after surgical and/or radiation-chemotherapy treatment at Fondazione Policlinico Universitario A.Gemelli IRCCS will be enrolled in the study.