Cutaneous metastases as an initial manifestation of visceral well-differentiated neuroendocrine tumor: a report of four cases and a review of 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 manifestations of pancreatic diseases

Although symptoms of pancreatic diseases such as pancreatitis, acute and chronic and, carcinoma of the pancreas are mainly gastrointestinal in nature, the extra-pancreatic symptoms are also important. These include skin symptoms, such as pancreatic panniculitis, acanthosis nigricans, livedo reticularis, necrolytic migratory erythema, cutaneous signs of hemorrhage, as in persons with severe acute pancreatitis, or the finding of cutaneous metastases of pancreatic carcinoma, which may be a sign of advanced disease. The pancreas is therefore one of those organs for which diagnosis and therapy are often multidisciplinary. In this review article, we summarize current knowledge of the possible skin manifestations of pancreatic disorders.

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.

Sweat-gland carcinoma with neuroendocrine differentiation (SCAND): a clinicopathologic study of 13 cases with genetic analysis

Low-grade neuroendocrine carcinoma of the skin (LGNECS) was proposed in 2017 as a new primary cutaneous neoplasm with neuroendocrine differentiation; however, it is not yet well known due to its rarity. Herein, we perform a detailed clinicopathologic analysis of 13 cases as well as panel DNA sequencing in three cases. The study included 12 males and 1 female with a median age of 71 (43-85) years. All lesions occurred on the ventral trunk. The mean tumor size was 2.2 (0.8-11.0) cm. The histopathology resembled that of well-differentiated neuroendocrine tumors (NETs) in other organs, but intraepidermal pagetoid spreading was seen in 8 (61.5%) cases and stromal mucin deposits in 4 (30.8%). Immunoreactivity for CK7, CK19, EMA, BerEP4, CEA, chromogranin A, synaptophysin, INSM1, GCDFP15, GATA3, ER, and bcl-2 were present in varying degrees in all tested cases. PTEN c.165-1G>A splice site mutation was detected by panel sequencing in one case, and GATA3 P409fs*99 and SETD2 R1708fs*4 in another case. Lymph node metastasis was seen significantly in cases with tumor size >2.0 cm [8/8 (100%) vs. 1/5 (20%)]. All three cases with size >3.0 cm were in unresectable advanced-stage [3/3 (100%) vs. 1/10 (10%)], and two of the three patients succumbed to the disease. The two cases of death revealed mild nuclear atypia (mitosis: 1/10 HPFs) and moderate nuclear atypia (2/10 HPFs). Thus, tumor size would be a better prognostic factor than nuclear atypia, mitotic count, and Ki67 index, unlike in NETs. These clinicopathologic and immunohistochemical features would represent the characteristics as skin adnexal tumors with apocrine/eccrine differentiation rather than NETs; therefore, we rename it as sweat-gland carcinoma with neuroendocrine differentiation (SCAND).

Rare-Site Primary Soft-Tissue Neuroendocrine Tumor with Metastases and Near-Complete Resolution with 177Lu-DOTATATE: Documenting a Promising Clinical Application of Peptide Receptor Radionuclide Therapy

Neuroendocrine tumors (NETs) of the skin or soft tissue are rare (mostly described as sites of metastasis), whereas primary soft-tissue NETs are extremely rare; they are usually diagnosed at advanced stages with distant metastases because of their indolent nature. We herein describe our experience with 2 such cases. In the first case, the NET originated in the retroperitoneal soft tissue, and in the second case, the patient was a middle-aged lady with NET arising from soft tissue in the pelvis. Both patients were treated with ¹⁷⁷Lu-DOTATATE in view of their somatostatin receptor-expressing metastatic lesions, demonstrating an excellent outcome as reflected by a complete metabolic response and near-complete anatomic response to the administered peptide receptor radionuclide therapy. The noteworthy factors of the reported cases were, first, unusual sites of primary tumor and, second, near-complete to complete symptomatic, anatomic, and metabolic resolution of the recurrent primary tumor and metastatic lesions with peptide receptor radionuclide therapy alone. NETs arising from rare anatomic locations are usually nonfunctioning, with good clinical outcomes, and ¹⁷⁷Lu-DOTATATE peptide receptor radionuclide therapy can be considered promising in patients with metastatic or advanced disease.

Incidental Finding of Benign Trichilemmal Cysts on 99mTc-Octreotide Scan

A 63-year-old woman with neuroendocrine carcinoma of the colon was referred to our department for staging with Tc-octreotide scan. Two focal, highly intense, superficial lesions were detected in patient's scalp and paralumbar region, medial to the right kidney. Pathology correlation was recommended, revealing them both to be benign trichilemmal cysts. This unexpected finding strengthens the hypothesis of Merkel cell carcinoma and trichilemmal cysts originating from pluripotent stem cells of adnexal epithelium, making a neuroendocrine differentiation for the latter plausible.

Rare breast and subcutaneous metastases from pancreatic neuroendocrine tumor: a case report

Background

Neuroendocrine tumors are a group of rare neoplasms, and the pancreatic neuroendocrine tumors (PNETs) represent only 1–2% of all pancreatic malignant tumors. The most common sites of these tumors include the gastrointestinal tract, lung, adrenal gland, and thyroid gland. Moreover, the most common sites of PNET metastases are the lymph nodes, liver, spleen, and bone.

Case summary

A 40-year-old woman with pT3N1 PNET underwent surgical excision of the lesion (12 cm, at the level of the pancreatic body and tail). Postsurgical treatment included chemotherapy and radiation, both of which the patient showed a good tolerance for. After a 12-month disease-free interval, however, the patient reported the development of a lesion in her left breast and a small lesion in the left posterior region of her neck. The lesions were surgically excised, and the histological findings characterized both as pancreatic neuroendocrine metastatic poorly differentiated neoplasms (G3). A re-staging CT scan showed multiple metastases in the left axillary, clavicular, and latero-cervical lymph nodes, as well as diffuse osteolytic-osteoblastic bone metastases, almost mimicking the behavior of a primitive breast tumor.

Conclusion

This case of breast and subcutaneous metastases from PNET should prompt awareness of potential metastatic lesions in unusual locations.

Primary hepatic carcinoid tumor metastasizing to eyelid: A case report

Purpose

We report a rare case of a metastatic carcinoid tumor to the right lower lid masquerading as a chalazion.

Observations

A 78-year-old Hispanic woman who presented with a 3-month history of a non-resolving chalazion on the right lower lid despite aggressive medical treatment. The patient had a history of noninfectious anterior uveitis and primary hepatic carcinoid tumor that was incidentally diagnosed during the initial uveitis work-up. The right lower eyelid lesion was biopsied and histological and immunopathological analysis revealed a well differentiated neuroendocrine tumor consistent with a carcinoid tumor.

Conclusionand Importance

Neuroendocrine tumors should be considered as part of the differential diagnosis of focal, vascularized eyelid masses. To the authors best knowledge this is the first reported case of primary hepatic carcinoid tumor with metastasis to the eyelids. We also highlight the importance of pursuing a histopathologic diagnosis, in the setting of a non-resolving or recurrent chalazion.

A common classification framework for neuroendocrine neoplasms: an International Agency for Research on Cancer (IARC) and World Health Organization (WHO) expert consensus proposal

The classification of neuroendocrine neoplasms (NENs) differs between organ systems and currently causes considerable confusion. A uniform classification framework for NENs at any anatomical location may reduce inconsistencies and contradictions among the various systems currently in use. The classification suggested here is intended to allow pathologists and clinicians to manage their patients with NENs consistently, while acknowledging organ-specific differences in classification criteria, tumor biology, and prognostic factors. The classification suggested is based on a consensus conference held at the International Agency for Research on Cancer (IARC) in November 2017 and subsequent discussion with additional experts. The key feature of the new classification is a distinction between differentiated neuroendocrine tumors (NETs), also designated carcinoid tumors in some systems, and poorly differentiated NECs, as they both share common expression of neuroendocrine markers. This dichotomous morphological subdivision into NETs and NECs is supported by genetic evidence at specific anatomic sites as well as clinical, epidemiologic, histologic, and prognostic differences. In many organ systems, NETs are graded as G1, G2, or G3 based on mitotic count and/or Ki-67 labeling index, and/or the presence of necrosis; NECs are considered high grade by definition. We believe this conceptual approach can form the basis for the next generation of NEN classifications and will allow more consistent taxonomy to understand how neoplasms from different organ systems inter-relate clinically and genetically.

Soft Tissue Primary Neuroendocrine Tumor: A Case Report

BACKGROUND Neuroendocrine tumors found in skin or soft tissues usually represent metastasis from other organs and are considered late manifestations of disease. Therefore, primary cutaneous and soft tissue neuroendocrine tumors are extremely rare. CASE REPORT We report a case of a 48-year-old male with a neuroendocrine tumor occurring in the subcutaneous abdominal fat, which had an echographic appearance of a vascular malformation. The finding was diagnosed as compatible with neuroendocrine tumor based on histopathological and immunohistochemical studies. No other sites of possible internal origin were detected on supplementary investigations. CONCLUSIONS Soft tissue neuroendocrine tumors may have an appearance on imaging studies that challenge physicians to make a correct diagnosis. Despite the rarity of these tumors, they should be included in the differential diagnosis of other soft tissue masses.

Well-differentiated neuroendocrine tumors in skin: Terminology and diagnostic utility of cytokeratin 5/6 and p63

BACKGROUND

Well-differentiated neuroendocrine tumors (WDNETs) in skin include metastases from visceral primary sites and very uncommonly, primary cutaneous carcinoid tumors. Cutaneous WDNET may present a diagnostic challenge and in particular can be mistaken for a benign skin adnexal tumor. In contrast to cutaneous adnexal tumors, metastatic adenocarcinomas to the skin are cytokeratin 5/6 (CK5/6) and p63 negative in the majority of cases. It is unclear if failure to stain with CK5/6 and p63 would be helpful in differentiating WDNETs from cutaneous adnexal neoplasms.

METHODS

We reviewed 10 cases of cutaneous WDNETs (8 cases of metastatic disease and 2 presumed primary carcinoid tumors of the skin) and performed immunohistochemical stains for CK5/6 and p63 on all cases.

RESULTS

All 10 cases were negative with both CK5/6 and p63.

CONCLUSION

Negative staining for CK5/6 and p63 can be helpful to distinguish WDNETs from cutaneous adnexal neoplasms. It is important to consider WDNETs in the differential diagnosis of cutaneous adnexal neoplasms as low-grade tumors may be the first sign of aggressive metastatic disease.

Low-Grade Neuroendocrine Carcinoma of the Skin (Primary Cutaneous Carcinoid Tumor) as a Distinctive Entity of Cutaneous Neuroendocrine Tumors: A Clinicopathologic Study of 3 Cases With Literature Review

There is scarcity of information on primary cutaneous low-grade neoplasms commonly known as carcinoid tumors, owing to their rarity. The authors present 3 cases that were named "low-grade neuroendocrine carcinoma of the skin" (LGNECS). These occurred in the dermis and subcutis of the anterior chest or the inguinal region in the elderly. Histologically, the tumors showed infiltrating proliferation of nests of various sizes, with low-grade neuroendocrine cytologic features but without mucin production. All cases exhibited varying degrees of intraductal tumor components. On immunohistochemical examination, these tumors expressed estrogen receptor alpha, progesterone receptor, androgen receptor, gross cystic disease fluid protein 15, mammaglobin, and GATA3 as well as neuroendocrine markers. Although a literature review revealed 8 additional possible cases with no evidence of other diseases, it was difficult to determine if these were true cases of LGNECS, because of the limited information available. Based on its characteristic histologic features and immunoprofile, it can be proposed designating LGNECS as a distinct entity among cutaneous neuroendocrine tumors. Otherwise, such tumors could be misdiagnosed as mammary carcinomas (particularly when involving the skin of the breast) or as metastatic visceral neuroendocrine tumors of the skin.

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

We report a new case of neuroendocrine carcinoma for which it was not possible to find the primary site until now. The recent medical literature about skin metastasis of neuroendocrine carcinoma (neuroendocrine tumor) is discussed.

Cutaneous metastasis as an initial presentation of a non-functioning pancreatic neuroendocrine tumor

Non-functioning pancreatic neuroendocrine tumors (NF-PNETs) are rare tumors that account for 2% of all pancreatic malignancy. About 60% of NF-PNETs present distant metastases and usually hepatic metastases. However, cutaneous metastases are very rare. Herein, we report our experience with a 60-year-old male who visited our outpatient clinic with a mass on his left hip. An abdominal computerized tomography scan demonstrated not only a left hip mass and an enlarged left inguinal lymph node, but also a huge heterogeneous enhancing mass on the pancreas. Initially, we removed the metastatic lesions, which was a small cell neuroendocrine carcinoma with 50% of the Ki-67 index in the histopathological report. After 3 wk, we performed a total pancreatectomy and a total gastrectomy. Four weeks after the 1^st operation, we detected a recurrence at the operative bed on his left hip, and subsequently removed the recurring mass. The patient was receiving chemotherapy based on etoposide and cisplatin treatment.

[Skin metastases seen at the pathology laboratory in Lome, Togo, between 2005 and 2014]

Introduction

L'objectif de cette étude était de documenter le profil épidémiologique et histologique des métastases cutanées vues au laboratoire d'anatomie pathologique (LAP) de Lomé.

Méthodes

Il s'agissait d'une étude descriptive et transversale portant sur des cas de métastases cutanées observées au LAP du CHU Sylvanus Olympio entre 2005 et 2014.

Résultats

Au cours de cette période d’étude, nous avons recensé 32 cas de métastases cutanées représentant 3,2% (1005 cas) de l'ensemble des cas de métastases enregistrées au LAP. L’âge moyen des patients atteints de ces métastases cutanées était de 42,6 ans et le sex-ratio (F/H) de 2,2. Sur le plan macroscopique, ces métastases étaient nodulaires dans 15 cas, bourgeonnantes dans 12 cas, ulcéré dans 3 cas et ulcéro-bourgeonnant dans 2 cas. Les types histologiques étaient représentés par les adénocarcinomes (19 cas, 59,4%), les carcinomes épidermoïdes (8 cas, 25%), la maladie de Paget (3 cas, 9,4%), le carcinome à petites cellules du type neuroendocrine (un cas, 3,1%) et le mélanome (un cas, 3,1%). Selon le degré de différenciation, les métastases cutanées étaient bien différenciées dans 14 cas (56%). Les principales localisations de ces métastases cutanées étaient le thorax (11 cas, 34,4%) suivi de l'abdomen (10 cas, 31,3%). Les cancers primitifs étaient surtout d'origine mammaire (14 cas, 43,7%).

Conclusion

Cette étude montre que les métastases cutanées sont relativement rares et les tumeurs malignes d'origine mammaire sont les tumeurs primitives prédominantes. Avec un pourcentage élevé des formes peu différenciées et celles indifférenciées, l'amélioration du plateau technique du LAP (immunohistochimie) permettra d'accroitre ses capacités diagnostiques.

Neuroendocrine carcinoma of the larynx with subcutaneous and intramuscular metastases: a case report

Neuroendocrine carcinomas have become increasingly recognized as more reports are emerging to describe these rare tumors. Primary sites include the lung, liver, throat, and other organs. Laryngeal neuroendocrine carcinomas are relatively rare, and the subtypes as well as the prognoses are quite different in most cases. Metastases to the liver, lungs and other parts are common. However, metastases to subcutaneous tissues or muscles have been rarely reported. We report a case of a neuroendocrine carcinoma of the larynx with subcutaneous and muscle metastases.