Like most head and neck cancers, carcinoma base of tongue is confined mostly to area above clavicles. Besides local spread, it metastasizes to regional neck nodes. The common sites of distant metastasis are lung, liver and bones [1]. Skin metastasis is rare with an incidence ranging from 0.7–2.7% and sometimes goes unnoticed due to its rare occurrence [2] [3] [4]. Skin metastasis usually occurs at scalp, neck or near the primary site [2] [5]. We report a rare case with skin metastasis on abdomen, hand, neck and scalp (Figure 1) (Figure 2) (Figure 3) (Figure 4) (Figure 5).

A 30-year-old male presented with lymph node mass left side of neck with duration of less than a month in July 2013. Fine needle aspiration cytology was done and it came out to be squamous cell carcinoma. Computed tomography (CT) scan of neck (29/7/13) showed an irregular enhancing soft tissue density lesion 2.7×2.6×1.9 cm in base of tongue crossing midline extending to epiglottis, pre epiglottic space and left vallecula (T4a) and enlarged necrotic lymph node in the left upper jugular region (level 2) 4.5×2.9 cm (N2). Magnetic resonance imaging scan confirmed these findings and was staged as stage 4 oropharyngeal carcinoma. Biopsy was taken from the mass at the base of tongue. Histopathology report showed poorly differentiated squamous cell carcinoma. Patient received hyperfractionated radiotherapy three-dimensional conformal radiotherapy (3 DCRT) to dose of 75.60 Gy in 63 fractions at the rate of 1.2 Gy per fraction with 2 fractions daily at an interval of 6 hours from 25/9/13 to 22 / 11/13 at a hospital in Kuwait. He received concurrent chemotherapy with cisplatin to dose of 40 mg/m2 for 5 cycles. He had complete clinical response for the primary cancer as evident by posttreatment CT scan done in Jan 2014 and Feb 2014 (Figure 6) (Figure 7) (Figure 8) (Figure 9) (Figure 10) (Figure 11) (Figure 12). He presented to us in March 2014. The patient had no evidence of disease locoregionally. He was subsequently followed-up in the OPD on regular basis. He developed multiple cutaneous nodules involving neck, abdomen, scalp and hand in March 2015. Initially he was given a course of antibiotics considering some infective pathology of skin, as there was no sign of recurrence at the local, nodal or any other distant site. Despite treatment the nodules did not resolve. Hence fine needle aspiration cytology was performed which revealed a metastatic squamous cell carcinoma consistent with primary squamous cell carcinoma of base of tongue (Figure 13) and (Figure 14). Considering the metastatic nature of the disease, patient was put on cisplatin based chemotherapy. Patient's response was poor and he expired after four months of detection of cutaneous metastasis.

Cutaneous metastasis are defined as isolated or multiple intradermal collections of tumor cells remote from the primary or loco-regional disease [2]. It is important to differentiate these lesions from extensions from the primary cancer, scar metastasis, metastasis from other primary skin cancers and primary cutaneous disorders [6] [7]. The frequency of cutaneous metastasis from internal malignancies varies from 0.7–9% of all cancer patients [8]. It is considered to be an uncommon entity in head and neck squamous cell cancers with an incidence of 1% [9] [7]. It is a general assumption that cutaneous metastasis indicates poor prognosis for the patient as information is lacking regarding the survival and management of these patients. The exact mechanism of cutaneous metastasis in oral cancers is not completely understood. There are three possible modes of spread namely direct spread, local spread and distant spread. Skin metastasis is thought to involve hematogenous spread where pulmonary circulation and filtration can be theoretically bypassed via the azygous, venous and vertebral venous system via Batson's plexus, allowing skin implantation [10]. There are very few case reports in literature about the skin metastasis from head and neck cancers. Veraldi et al. noted the rarity of skin metastasis from laryngeal cancers and showed only 12 reported cases in a review of literature [5]. The treatment of cutaneous metastasis is, in general, palliative. Options available are surgical excision, radiotherapy, and chemotherapy or combination of these. As for now, all patients do poorly and succumb rapidly to the disease [11] [12] [13].

Cutaneous metastasis from squamous carcinoma of base of tongue is a very rare event. Clinical encounter of this case has taught us that whenever a patient of head and neck cancer presents with skin lesions, possibility of cutaneous metastasis should be kept in mind and confirmatory investigation should be done.

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