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

Metastatic Renal Cell Carcinoma to the Scalp: A Case Report With Review of Literature

Renal cell carcinoma (RCC) is the most common type of renal neoplasm. It accounts for 3% of solid tumors in adults and mostly affects men with the peak incidence between the fifth and seventh decades. It metastasizes mainly through the hematogenous spread, and the lung is the most common site of metastasis followed by bone, lymph node, liver, brain, and adrenal glands. Skin metastasis is extremely rare and accounts for <7% of RCC metastases, with the scalp and face being the most reported sites. Skin metastases are usually diagnosed at a later stage of the disease, commonly post-nephrectomy, and are regarded as a poor prognostic factor. Here we report a case of a 54-year-old male who presented with a red, pedunculated, bleeding, and nontender scalp lesion (2x2cm in size) found on the right parietal area. with a history of left radical nephrectomy and adjuvant chemotherapy for clear cell RCC 17 years ago, as well as laminectomy and radiotherapy for bone metastases in C5 and C6 in 2015. After surgical excision of the scalp lesion, histology revealed metastatic clear cell RCC. The patient was doing well post-surgical excision and was referred back to oncology where palliative care and supportive treatment were initiated. In the span of five months post-resection, he developed several conditions where his health further deteriorated. He was announced dead in September 2022 due to cardiac arrest. This case highlights the occurrence of scalp metastases long after the surgical resection of RCC.

Cutaneous metastatic renal cell carcinoma to the scalp

Renal cell carcinoma (RCC) represents 2% to 3% of human cancers and is aggressive, with metastatic capability. The frequent metastatic sites are lung, bone, and liver. Reports of RCC metastatic to skin, and especially scalp are rare. Here we present an 83-year-old woman who was diagnosed with RCC 19 years prior and had a metastatic scalp lesion. An 83-year-old woman presented with a red-to-purple, protruding lesion at the right parietotemporal area. Twenty-three years ago, a right renal mass was incidentally discovered on ultrasound through a routine medical examination. She underwent right nephrectomy for RCC 4 years later. Five months after nephrectomy, new lung nodules were observed. Fifteen years after nephrectomy, metastatic lesions were found in the pelvic bone. She visited dermatology department for evaluation of the new scalp lesion, a year before she first visited our department. Despite chemotherapy, the mass was gradually enlarged. She consulted the plastic surgery department for management of the metastatic RCC was successfully treated with total excision including a 1-cm safety margin, local flap, and STSG coverage. Complete healing was observed, without evidence of recurrence during a 7-month followup. Metastases to the skin are rare, but must be kept in mind because of its high metastatic ability and poor prognosis.

State of the art of Mohs surgery for rare cutaneous tumors in the Spanish Registry of Mohs Surgery (REGESMOHS)

BACKGROUND

The use of Mohs micrographic surgery (MMS) for rare cutaneous tumors is poorly defined. We aim to describe the demographics, tumor presentation and topography, surgery characteristics and complications of MMS for rare cutaneous tumors in a national registry.

METHODS

Prospective cohort study of patients treated with MMS in Spain between July 2013 and June 2018. The inclusion criteria were patients with cutaneous tumors with final diagnosis different from basal cell carcinoma, squamous cell carcinoma, dermatofibrosarcoma protuberans, or any kind of melanoma.

RESULTS

Five thousand and ninety patients were recorded in the registry, from which only 73 tumors (1.4%) fulfilled the inclusion criteria: atypical fibroxanthoma (18), microcystic adnexal carcinoma (10), extramammary Paget's disease (7), Merkel cell carcinoma (5), dermatofibroma (4), trichilemmal carcinoma (4), desmoplastic trichoepithelioma (4), sebaceous carcinoma (3), leiomyosarcoma (2), porocarcinoma (2), angiosarcoma (2), trichoblastoma (1), superficial acral fibromyxoma (1), and others (10). No intra-surgery morbidity was registered. Postsurgery complications appeared in six patients (9%) and were considered mild. Median follow-up time was 0.9 years during which three Merkel cell carcinomas, one angiosarcoma, one microcystic adnexal carcinoma, and four others recurred (12.3%).

CONCLUSION

This national registry shows that rare cutaneous tumors represent a negligible part of the total MMS performed in our country with a low complication rate.

TRPM8: a potential target for cancer treatment

Transient receptor potential (TRP) cation channel superfamily plays critical roles in variety of processes, including temperature perception, pain transduction, vasorelaxation, male fertility, and tumorigenesis. One of seven families within the TRP superfamily of ion channels, the melastatin, or TRPM family comprises a group of eight structurally and functionally diverse channels. Of all the members of TRPM subfamily, TRPM8 is the most notable one. A lot of literatures have demonstrated that transient receptor potential melastatin 8 (TRPM8) could perform a myriad of functions in vertebrates and invertebrates alike. In addition to its well-known function in cold sensation, TRPM8 has an emerging role in a variety of biological systems, including thermoregulation, cancer, bladder function, and asthma. Recent studies have shown that TRPM8 is necessary to the initiation and progression of tumors, and the aberrant expression of TRPM8 was found in varieties of tumors, such as prostate tumor, melanoma, breast adenocarcinoma, bladder cancer, and colorectal cancer, making it a novel molecular target potentially useful in the diagnosis and treatment of cancer. This review outlines our current understanding on the role of TRPM8 in occurrence and development of different kinds of tumor and also includes discussion about the regulation of TRPM8 during carcinogenesis as well as therapeutic potential of targeting TRPM8 in tumor, which may be utilized for a potential pharmacological use as a target for anti-cancer therapy.