Metastatic Tumors to the Nail Unit: Subungual Metastases

Mohs surgery in metastatic cancer: renal cell carcinoma solitary cutaneous metastasis and visceral tumor metastases to skin treated with microscopically controlled surgical excision

BACKGROUND

Mohs micrographic surgery is the reference standard treatment for primary cutaneous malignancies.

OBJECTIVES

The purpose of this case study is to demonstrate that Mohs surgery may be considered as a possible treatment for a solitary metastatic tumor under the appropriate circumstances.

METHODS

We report a patient in whom a solitary cutaneous metastasis of renal cell carcinoma (RCC) was successfully treated with microscopically controlled surgical excision, and cite instances of the successful management of cutaneous metastases using the Mohs surgical technique in oncology patients reported in the literature. Patient reports and previous reviews of the subject were critically assessed. Salient features are presented.

RESULTS

Metastases to the skin are rare in RCC. Albeit rarely, surgical excision, particularly Mohs micrographic surgery, has been used for the removal of isolated RCC cutaneous metastases. In the present patient with metastatic RCC, a solitary cutaneous metastasis on the occipital scalp was successfully treated with Mohs micrographic surgery. There was no recurrence of the lesion after two years of follow-up; however, the patient eventually succumbed to progressive disease.

CONCLUSIONS

We suggest that, in the appropriate setting, surgical excision of isolated cutaneous metastases using microscopically controlled margins at the time of surgery should be added to the indications for Mohs surgery.

Cutaneous metastases of internal tumors

Cutaneous metastases are relatively rare in clinical practice and their diagnosis requires a high index of suspicion because clinical findings can be subtle. These metastases reveal the presence of disseminated malignant disease and can lead to the diagnosis of unsuspected internal tumors or the spread or recurrence of an already diagnosed tumor. Early recognition of cutaneous metastases can facilitate prompt and accurate diagnosis resulting in early treatment; however, they are generally indicative of a poor prognosis. Some tumors have a predilection to metastasize to specific areas. Recognition of these patterns provides essential information that can guide the search for the underlying tumor.

Clinical manifestations of cutaneous metastases: a review with special emphasis on cutaneous metastases mimicking keratoacanthoma

Approximately 5% of oncology patients develop cutaneous metastases, with only a small number of these patients (less than 1%) having metastatic skin lesions as the first sign of their visceral cancer. Metastases tend to occur on skin surfaces in the vicinity of the primary tumor. However, any site may be affected by cutaneous metastases. Skin metastases can present with several morphologies including, albeit rarely, keratoacanthoma-like lesions. Keratoacanthoma is a keratinous tumor that morphologically appears as a nodule with a central keratin-filled crater. This article reviews the characteristics of oncology patients whose cutaneous metastases mimicked a keratoacanthoma, including illustrations from our patient, a 53-year-old Caucasian man whose metastatic esophageal adenocarcinoma not only presented with a keratoacanthoma-like tumor on his upper lip but also a forehead macule and a scalp nodule. We also report keratoacanthoma-like presentations from literature cases of breast cancer, chondrosarcoma, and pulmonary malignancies. The lesions were discovered 3-24 months after diagnosis of visceral cancer and led to the discovery of unsuspected lung cancer in two patients. Most of the patients (60%) died within 2 months of discovery of the keratoacanthoma-like cutaneous metastases. We also reviewed the literature and discuss other morphologies of cutaneous metastases in patients whose primary tumors were in the breast, lung, and esophagus. In addition, we review from the literature other examples of tumors that present as metastatic nodules on the scalp. The possibility of cutaneous metastasis should be entertained and pathologic evaluation should be considered in an oncology patient with underlying visceral malignancy who develops a keratoacanthoma-like lesion.

Metastatic esophageal adenocarcinoma of the great toe: a case report

Owing to the rarity of metastatic disease to the bones of the foot, the guidelines for the proper care and workup of such conditions are inconsistent. The present case illustrates the evaluation of a patient with established esophageal adenocarcinoma that metastasized to involve the hallux, which had not been confirmed by previous imaging scans. The purpose of reporting the present case was to aid in establishing a protocol for a multidisciplinary approach to patient care and evaluating the entire body when performing metastatic disease treatment. As the present case has shown, evaluation of various abnormalities such as chronic paronychia could mask additional underlying conditions related to the patient's primary cancer.

Cutaneous manifestations of breast carcinoma

The incidence of breast carcinoma cutaneous manifestation in patients with breast carcinoma is 23.9%. The most common sites of breast carcinoma cutaneous manifestation are the chest wall and abdomen, but they can occur at the extremities and in the head/neck region. Due the high incidence of breast carcinoma, these cutaneous manifestations are the most common metastases seen by dermatologists. In clinical practice, cutaneous metastases show a wide range of clinical manifestations. Nodules are the most common presentation, but several other patterns are described below.

The hand in metastatic disease and acral manifestations of paraneoplastic syndromes

Metastatic tumors to the hand and wrist are rare, accounting for approximately 0.1% of all metastatic lesions to the skeleton. The biochemically mediated pathways of bone metastases, the location of the hand at the distal extremity, and the small amount of marrow in the bones of the hand and wrist account for the low prevalence of acrometastases. More rarely, hand dermatologic and soft tissue changes of paraneoplastic syndromes herald an occult malignancy.

Tumors of the perionychium

Tumors of the perionychium are often subtle and difficult to diagnose. Because they are somewhat uncommon, the early symptoms of these tumors, which may include vague pain, local swelling, nail discoloration, nail deformity, or drainage, may be mistaken for signs of infection and/or trauma and therefore treated with topical or oral antibiotics for some time. Functionally important in enhancing fingertip sensation, protection, and manipulating fine objects, the perionychium is continuously subject to day-to-day trauma and injury that can alter the natural contours and growth patterns of the nail plate. Bacterial, viral, or fungal infections can incite swelling, pain, and distortion of the perionychium as well. Both infection and trauma, then, can mask underlying tumors or growths that would delay their diagnosis. A delay in treatment can be devastating if the growth of the perionychium happens to be malignant. Therefore, a general understanding of the signs and symptoms of the perionychium tumors is needed by all physicians and surgeons treating nail problems.

Cutaneous nephrology

There are numerous cutaneous findings that may be related to coexistent renal disease. An astute clinician may use careful skin examination to make early diagnosis of renal conditions in some cases, and institute appropriate therapy as soon as indicated.