Cutaneous Metastasis of Neuroendocrine Carcinoma with Unknown Primary Site: Case Report and Review of the Literature

Cutaneous Neuroendocrine Metastases of Visceral Origin Responsive to Surgical Resection and Targeted Radionuclide Therapy

Neuroendocrine neoplasms (NENs) encompass a diverse range of biologically and behaviorally distinct epithelial malignancies that derive from neuroendocrine cells. These neoplasms are able to secrete a variety of bioactive amines or peptide hormones. The majority of NENs are well-differentiated and are defined as neuroendocrine tumors (NETs). While NETs are known to frequently metastasize to lymph nodes, liver, and lungs, spread to the skin is extremely rare and is often a late finding. Because cutaneous metastasis from a visceral site represents distant tumor dissemination, prompt histologic diagnosis is critical in terms of selecting further treatment options and ultimately impacts subsequent prognosis. This report presents a man with painful cutaneous NET metastases initially on the face then scalp. He had a prior history of longstanding and progressive stage IV visceral disease. Multimodal therapy with initial surgical resection of the larger facial lesion and radionuclide infusion therapy was undertaken. Excision fully removed the temple lesion and resolved pain. Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE, a radiolabeled somatostatin analog that targets somatostatin receptors on NETs, was given along with maintenance lanreotide therapy, which resolved the scalp lesion, prevented recurrence of prior lesions and development of new cutaneous metastases, and controlled his visceral disease. PRRT has not been previously described in the management of cutaneous NET metastases. Due to the rare nature of cutaneous NET metastases, there is no consensus regarding optimal management. As such, we propose novel multimodal therapy involving excision and targeted radionuclide therapy as a possible effective option.

Skin Metastases of Gastrointestinal Neuroendocrine Tumors – Literature Review

<b> Introduction:</b> Gastrointestinal neuroendocrine neoplasms arise from cells of the diffuse endocrine system (DES) located in the digestive tract. They are often diagnosed in an advanced stage, when distant metastases appear. Skin metastases of neuroendocrine tumors are extremely rare. </br></br> <b>Aim:</b> The aim of the study was to collect and analyze cases of skin metastases of gastrointestinal neuroendocrine neoplasms. </br></br> <b>Materials and methods:</b> A literature search across PubMed and Medline databases from 1969 up to 2021 was performed. We reviewed English literature according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. The following keywords were used: “neuroendocrine tumor”, “neuroendocrine neoplasm”, “neuroendocrine carcinoma”, “NET”, “NEN”, “skin and cutaneous metastases”, “lymph nodes”. The characteristics of patients, grading, tumor localization and other data that was found in publications were assessed. Case reports and case series were included. </br></br> <b>Results:</b> The initial search strategy yielded 14 results in PubMed and 3 in the Medline database. We removed duplicates after we imported the citations with a citation manager. We found 17 publications concerning skin metastases of neuroendocrine neoplasms. The analysis of 18 cases concerned 13 NECs and 5 NETs. In most cases, the metastases are small, painless and located on the scalp or lower extremities. Skin metastases may be the first symptom of the disease. The pancreas is the most common primary tumor site.</br></br> <b>Conclusions:</b> NEN metastases to the skin are often diagnosed with disseminated neoplastic process, which is associated with poor prognosis and high mortality. NET metastases to the skin may occur with an unknown primary site. Skin metastases of neuroendocrine tumors should be considered during the diagnosis of skin tumors.

Unexpected response to palliative radiotherapy for subcutaneous metastases of an advanced small cell pancreatic neuroendocrine carcinoma: a case report of two different radiation schedules

Background

Skin metastases from pancreatic neuroendocrine carcinoma (PNEC) are rare and their palliative treatment is challenging. We report our experience in the multimodal management of one of the few reported cases of metastatic PNEC with multiple visceral and subcutaneous secondary lesions, focusing on the effectiveness of palliative radiotherapy for skin metastases.

Case presentation

A 61-years old woman affected by a metastatic PNEC – with subcutaneous growing and bleeding secondary lesions (at the scalp, right scapular region and at the back of the left thoracic wall, respectively) – obtained a successful control of visceral metastases with the use of chemotherapy and an unexpected local response of her skin metastases with palliative radiotherapy. In particular, two subsequent radiation treatments were performed using different fractionation schedules (30 Gy in 10 fractions and 20 Gy in 5 fractions, respectively). Both radiation treatments were well-tolerated and patient’s quality of life was improved. Local response was maintained until patient’s death – that occurred due to cachexia.

Conclusions

The presented case highlights the effectiveness and the good tolerance of radiotherapy in the treatment of subcutaneous metastases; nevertheless, further knowledge of the optimal local palliative approach for PNEC metastatic sites is necessary. The experience gained in this work is the occasion to encourage a routine integrated multidisciplinary team management of metastatic PNECs because of their clinical complexity. The aim is to guarantee the optimization of the care with personalized and more effective systemic and local treatments – also including supportive cares and treatment-related side effects management.

Poorly differentiated neuroendocrine rectal carcinoma with uncommon immune-histochemical features and clinical presentation with a subcutaneous metastasis, treated with first line intensive triplet chemotherapy plus bevacizumab FIr-B/FOx regimen: an experience of multidisciplinary management in clinical practice

Background

Neuroendocrine tumors (NETs) are heterogeneous, widely distributed tumors arising from neuroendocrine cells. Gastrointestinal (GI)-NETs are the most common and NETs of the rectum represent 15, 2% of gastrointestinal malignancies. Poorly differentiated neuroendocrine carcinomas of the GI tract are uncommon. We report a rare case of poorly differentiated locally advanced rectal neuroendocrine carcinoma with nodal and a subcutaneous metastasis, with a cytoplasmic staining positive for Synaptophysin and Thyroid Transcription Factor-1.

Case presentation

A 72-year-old male presented to hospital, due to lumbar, abdominal, perineal pain, and severe constipation. A whole-body computed tomography scan showed a mass of the right lateral wall of the rectum, determining significant reduction of lumen caliber. It also showed a subcutaneous metastasis of the posterior abdominal wall. Patient underwent a multidisciplinary evaluation, diagnostic and therapeutic plan was shared and defined. The pathological examination of rectal biopsy and subcutaneous nodule revealed features consistent with small-cell poorly differentiated neuroendocrine carcinoma. First line medical treatment with triplet chemotherapy and bevacizumab, according to FIr-B/FOx intensive regimen, administered for the first time in this young elderly patient affected by metastatic rectal NEC was highly active and tolerable, as previously reported in metastatic colo-rectal carcinoma (MCRC). A consistent rapid improvement in clinical conditions were observed during treatment. After 6 cycles of treatment, CT scan and endoscopic evaluation showed clinical complete response of rectal mass and lymph nodes; patient underwent curative surgery confirming the pathologic complete response at PFS 9 months.

Discussion and conclusions

This case report of a locally advanced rectal NEC with an unusual subcutaneous metastasis deserves further investigation of triplet chemotherapy-based intensive regimens in metastatic GEP NEC.