Asymptomatic Subcutaneous Nodules Heralding Recurrence of Gastric Adenocarcinoma.

Sir,

A 65-year-old male patient, known case of gastric adenocarcinoma was referred from oncology center to our dermatology outpatient clinic for multiple skin lesions of 1-month duration. He was diagnosed as a case of gastric adenocarcinoma diffuse type with esophageal involvement (stage 3A). He underwent esophagectomy with partial gastrectomy with feeding jejunostomy and tracheostomy 1½ years back. He received concurrent chemotherapy (6 cycles 5-fluorouracil 500 mg/week) and radiotherapy 50.4 Gy/28#. He remained in remission for 4 months and after that he presented to us with above-mentioned complaints. On examination the patient was cachexic, anemic, and had multiple asymptomatic subcutaneous skin color to slightly erythematous nodular lesions varying in size from 1 cm × 1 cm to 3 cm × 2 cm all over the body. Few of the lesions present over scalp were ulcerated [Figure 1]. He had significant cervical lymphadenopathy; however, there was no organomegaly. His hematological examination revealed combined nutritional deficiency anemia (hemoglobin 6 mg/dl). Xray chest and ultrasonographic examination was not contributory. His cervical lymphadenopathy was reactive in nature. He underwent histopathological examination from the subcutaneous nodule, which demonstrated the presence of gland-like tumor cells infiltrating collagen bundles in the deep dermis and subcutis with associated desmoplasia and acute inflammatory infiltrate [Figure 2]. At higher magnification (×400) tumor cells had intracytoplasmic vacuoles (mucin) and atypical nuclei [Figure 3]. He was referred to oncology center with a diagnosis of cutaneous metastasis of mucinous adenocarcinoma gastric diffuse type for further workup and management. Unfortunately, he was lost to follow-up.

Figure 1

Multiple skin colored to slightly erythematous subcutaneous nodules over the trunk and scalp

Figure 2

Histopathological examination showing gland-like tumor infiltrating collagen bundles in deep dermis and subcutis associated with desmoplasia and acute inflammatory infiltrate (H and E, ×200)

Figure 3

Histopathological examination showing tumor cells with intracytoplasmic vacuoles (mucin) and atypical nuclei (H and E, ×400)

Cutaneous metastases refer to the spread of the tumor to the skin, from its primary site of origin and occur in 0.6% to 10.4% of cancer patients, representing 2% of all skin tumors.[1] They may represent an initial presenting sign of primary malignancy or may herald recurrence/relapse of a treated malignancy and are therefore generally associated with a poor prognosis.[1] In women, breast cancer, colorectal cancer, and melanoma while in men melanoma, lung cancer, and colorectal cancer are the most common sources of cutaneous metastases; with thorax or abdominal region being the most commonly involved sites.[2] Clinically, cutaneous metastases may present as dermal/subcutaneous nodules, plaques, papules, tumors, macules, bullous, or papulosquamous lesions.[2] They may be asymptomatic or associated with pain and tenderness.[2] Cutaneous metastases may occur through lymphatic spread, hematogenous spread, direct contiguity or iatrogenic implantation,[3] and may precede the internal malignancy (“precocious” mets) or occur simultaneously with the primary tumor (“synchronous” mets).[4] The exact mechanism is unknown but it has been proposed that the tumor cells have high affinity for the chemokine milieu of skin and certain factors may be secreted by the primary tumor which prepares the “premetastatic niche.”[4]

Cutaneous metastases occur in 0.2-0.4% of cases of gastric carcinoma cases.[5] Clinically, it presents as solitary or multiple nodules and may rarely present as carcinoma en cuirasse, carcinoma erysipeloides, neoplastic alopecia, and zosteriform metastasis.[5] The most commonly affected region is the abdomen with neck, head, eyebrow, axilla, chest, and fingertip being the other sites. Gastric adenocarcinomas represent approximately 95% of gastric tumors and are histopathologically classified as papillary adenocarcinomas, tubular adenocarcinomas, mucinous adenocarcinomas, or signet ring cell carcinomas.[6] Signet ring cell carcinomas comprise only 8.7% of all gastric cancers.[6] Cyclooxygenase 2 is associated with gastroesophageal adenocarcinoma and aid in diagnosis in difficult cases. In a recent review,[6] cutaneous metastases were seen as the first manifestation of gastric carcinoma in 6.4–7.4% of cases, appeared between 33 and 71 years of age (mean - 55 years), occurred commonly in males (7:3). It presented as a single lesion in only 18% of cases, and the most common site was chest and face for multiple regions and chest or abdomen for single lesions. They also found that the mean interval between gastric cancer detection and diagnosis of cutaneous metastasis was 7.3 months, the primary tumor was unknown at the time of diagnosis of the cutaneous metastasis in 64% of cases and survival time was <1-year.[6] For widespread cutaneous and subcutaneous metastases palliative therapy including radiotherapy, systemic chemotherapy, polychemotherapy, isolated limb perfusion, interferon alpha injections, cryotherapy, laser ablation, or radiofrequency ablation may be useful.[2] There are few reports of cutaneous metastases arising from gastric carcinomas[56] in which cutaneous metastases were the initial presenting sign of underlying undiagnosed gastric malignancy. Our case is unique as cutaneous metastases were the first sign of signet cell gastric adenocarcinoma. Thus, it signifies the need of detailed history, examination, and the high index of suspicion to clinch a diagnosis in a cachexic old male patient presenting with significant weight loss.

To conclude, cutaneous metastasis occurs infrequently and may be an early sign of presentation or recurrence of the primary tumor. It is therefore important to recognize them early for prompt treatment, which may have a profound effect on patient management and survival.

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Conflicts of interest

There are no conflicts of interest.