Malignant melanoma within squamous cell carcinoma and basal cell carcinoma: is it a combined or collision tumor?--a case report and review of the literature

A Rare Case of a Basomelanocytic Tumor

ABSTRACT

Basal cell carcinomas and melanoma are common cutaneous malignancies. However, the development of a basomelanocytic tumor that simultaneously includes elements of melanoma and basal cell carcinoma is extremely rare. We present the case of an 84-year-old man who presented with a nonpigmented, nonulcerated pink nodule of his left upper back and discuss the current management recommendations for basomelanocytic tumors.

Case Report: The first case of primary pulmonary collision tumor comprising mixed squamous cell and glandular papilloma and glomus tumor

A collision tumor is a rare entity, particularly if occurring in the lung. We report a case of a 57-year-old woman with a primary pulmonary collision tumor comprising mixed squamous cell and glandular papilloma (MSGP) and glomus tumor (GT). An abnormal mass was discovered in the right lung by computed tomography (CT) of the chest. A right lower lobectomy with mediastinal lymph node dissection was performed. Histological examination of the surgical specimen suggested that the lung cancer was composed of two neoplastic components. To the best of our knowledge, this is the first report of a primary pulmonary collision tumor comprising two benign tumors of different origins, which were MSGP and GT.

Cutaneous Malignant Squamomelanocytic Tumor: A Case Report of a Rare Neoplasm

ABSTRACT

Cutaneous squamomelanocytic tumor (SMT) is an exceedingly rare cutaneous malignancy characterized by the presence of both squamous cell carcinoma and malignant melanoma within a single tumor. SMT typically presents clinically as keratotic skin papulonodules, most commonly occurring on the face, scalp, or other sun-exposed areas of middle-aged to elderly White male patients. Owing to the rare nature of this tumor, the histogenesis and prognosis remain relatively unclear. Histopathological examination of the tangential biopsy revealed an invasive cutaneous malignancy consisting of 2 distinct yet closely associated atypical cell populations: (1) a population of atypical squamoid epithelial cells arranged in cords and keratin pearls and (2) a population consisting of atypical, spindled cells with fine melanin pigment arranged in confluent sheets. Both populations of atypical cells emanated in an invasive pattern from the underside of the overlying epidermis into the deep dermis. Squamomelanocytic tumors are among the rarer types of collision tumors between 2 malignant lesions as most are basomelanocytic. For most reported SMTs, the melanoma population comprises epithelioid cell morphology, whereas our tumor is composed of spindled cell morphology. In this article, we exemplify a unique case of SMT in an 87-year-old male patient.

Metastatic Melanoma to a Neurofibroma

ABSTRACT

We present an extraordinary case of metastatic cutaneous melanoma to a pre-existing neurofibroma in a 75-year-old man with a history of primary invasive melanoma in an anatomically close vicinity. Histological examination of the metastatic melanoma showed a well-circumscribed intradermal nodule of frankly malignant epithelioid melanocytes without an intraepidermal component, surrounded and sharply demarcated from a diffuse spindle cell proliferation with morphological features of a neurofibroma. The spindle cell component showed bland cytologic features, with no mitotic activity or lymphocytic inflammation and no features of malignancy. By immunohistochemistry, both components expressed S100, while HMB45 positivity and complete loss of p16 were only observed in the epithelioid cells. The morphologically distinct areas were analyzed by fluorescent in situ hybridization, which demonstrated an abnormal profile (gain of RREB1 and homozygous loss of CDKN2A) in the epithelioid nodule; however, no abnormalities were detected in the spindle cell component. Next-generation sequencing showed somatic NRAS and PTEN mutations in the melanoma cells only. The overall molecular findings supported the immunomorphological diagnosis of metastatic melanoma within a neurofibroma over the potential differential diagnosis of melanoma with a neurofibroma-like spindle/desmoplastic component.

Clinical-Dermoscopic-Histopathological Correlations in Collision Skin Tumours

Objectives

Collision tumours are rare situations characterised by the coincidence of two different skin neoplasms in the same lesion.

Methods

We have analyzed 41 collision skin tumours from one department in the clinical-dermoscopic-histopathologic correlations.

Results

We present 41 collisions tumours. The mean age of our patients was 67.9 years, the mean diameter of the lesion was 11.6 mm. The most frequent locations were trunk (27 lesions) and head/neck (11 lesions). The collisions were classified as benign/benign (13 cases), benign/malignant (25 cases) and malignant/malignant (3 cases). The most frequent participants were seborrheic keratosis (24 cases), malignant melanoma (17 cases), melanocytic nevus (14 cases), basal cell carcinoma (12 cases) and heamangioma (10 cases). Thirty cases were of "dominant/minor" type and 11 cases of "half to half" type. Malignant tumours were a part of 28 collisions; these lesions were larger, patients were older and the malignant part was dominant in most cases. More than half of the collisions were unexpected by the initial clinical examination. Six collisions were missed by the initial histopathological examination.

Conclusions

Collision tumours can be missed by clinical or even histopathological examination. Dermoscopy is very helpful in the recognizing of difficult cases and cooperating with the histopathologist.

A Wolf in Sheep's Clothing: Collision of Melanoma and Keratoacanthoma

Collision tumors consisting of melanoma and squamous cell carcinoma are very rare. We present the case of a deceptive hyperkeratotic nodule on the forearm of a 72-year-old woman, which clinically appeared to be a squamous cell carcinoma, keratoacanthoma type. Histological examination surprisingly revealed a coexisting epithelioid melanoma. Thus, this case report shows the importance of an early histopathological and immunohistochemical workup to prevent unnecessary diagnostic and therapeutic delay with negative effects on prognosis.

A rare case of invasive melanoma likely arising from passenger melanocytes of a basal cell carcinoma

Neoplasms consisting of different cell lineages within a single skin specimen are rare, yet well documented in the literature. However, to date, there appears to be no report of invasive melanoma arising directly from the passenger melanocytes of a basal cell carcinoma (BCC). We present a case of a 91-year-old male with a suspicious lesion on the ear. Histopathology and immunohistochemical staining revealed BCC closely intertwined with invasive melanoma that exhibited foci of chondroid differentiation. The melanoma appeared to arise from the benign-appearing passenger melanocytes of the BCC and lacked connection to the overlying epidermis or an in situ component. Multiple dermatopathologists reviewed the case and agreed that the most likely explanation for the histopathologic findings was that the invasive melanoma arose from the passenger melanocytes within the BCC.

Multiple Skin Neoplasms at One Site (MUSK IN A NEST): A Comprehensive Review of Basal Cell Carcinoma and Benign or Malignant "Collision" Tumors at the Same Cutaneous Location

Multiple skin neoplasms at one site (MUSK IN A NEST), initially referred to as a collision tumor, describes the occurrence of two or more benign or malignant neoplasms that are adjacent or intermingled at the same cutaneous site. A mononeoplastic cutaneous tumor refers to a single tumor at any cutaneous site. Two, three, four, five, and six tumors at the same site are described as dineoplastic, trineoplastic, tetraneoplastic, pentaneoplastic, and hexaneoplastic cutaneous tumors, respectively; the prefixes are based on the numerical multiplier used by the International Union of Pure and Applied Chemistry (IUPAC). MUSK IN A NEST can be classified based upon their mechanism of pathogenesis-either being composed of mixed clones of cells (clonalium, which has three subtypes: collision, colonization, and combination) or the same clone of cells that has undergone clonal evolution (clonalidem, which has one subtype: biphenotypic). Basal cell carcinoma (BCC)-associated MUSK IN A NEST can be observed with either benign tumors, malignant tumors, or both. Nevi and seborrheic keratoses are the most common benign tumors associated with BCC; melanoma in situ and invasive melanoma are the most commonly reported malignant tumors associated with BCC. The definitive etiology of BCC-associated MUSK IN A NEST remains to be established-whether the development of the BCC at that site occurs as a direct or indirect consequence of the coexisting neoplasm or whether the occurrence of the BCC and the other neoplasm is merely the result of a coincidental juxtaposition of the tumors.

Collision tumors: A review of their types, pathogenesis, and diagnostic challenges

A collision tumor is a neoplastic lesion comprised of two or more distinct cell populations that maintain distinct borders. Collision tumors, which are rare but well documented, can be composed of two benign tumors, a benign and malignant tumor, and two malignant tumors. Although case reports and reviews on specific types of collision tumors exist, a cohesive source discussing these tumors is lacking. We critically reviewed the literature by analyzing case reports and retrospective studies in order to evaluate the following regarding collision tumors: definitions, types, pathogenesis, diagnosis, and management. Reports of these tumors are infrequent but not insignificant, and accurate classification and diagnosis will lead to better patient outcomes.

Comprehensive germline mutation analysis and clinical profile in a large cohort of Brazilian xeroderma pigmentosum patients

BACKGROUND

Xeroderma pigmentosum (XP) patients present a high risk of developing skin cancer and other complications at an early age. This disease is characterized by mutations in the genes related to the DNA repair system.

OBJECTIVES

To describe the clinical and molecular findings in a cohort of 32 Brazilian individuals who received a clinical diagnosis of XP.

METHODS

Twenty-seven families were screened for germline variants in eight XP-related genes.

RESULTS

All patients (N = 32) were diagnosed with bi-allelic germline pathogenic or potentially pathogenic variants, including nine variants previously undescribed. The c.2251-1G>C XPC pathogenic variant, reported as the founder mutation in Comorian and Pakistani patients, was observed in 15 cases in homozygous or compound heterozygous. Seven homozygous patients for POLH/XPV variants developed their symptoms by an average age of 7.7 years. ERCC2/XPD, DDB2/XPE and ERCC5/XPG variants were found in a few patients. Aside from melanoma and non-melanoma skin tumours, a set of patients developed skin sebaceous carcinoma, leiomyosarcoma, angiosarcoma, mucoepidermoid carcinoma, gastric adenocarcinoma and serous ovarian carcinoma.

CONCLUSIONS

We reported a high frequency of XPC variants in 32 XP Brazilian patients. Nine new variants in XP-related genes, unexpected non-skin cancer lesions and an anticipation of the clinical manifestation in POLH/XPV cases were also described.

Triple collision tumor comprising Merkel cell carcinoma with an unusual immunophenotype, squamous cell carcinoma in situ, and basal cell carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive primary cutaneous neuroendocrine cancer which almost always exhibits the cytokeratin (CK)20+/thyroid transcription factor (TTF)-1- immunophenotype. MCC may occur concurrently with squamous cell carcinoma, Bowen disease, and/or basal cell carcinoma (BCC), with some evidence that MCCs which occur in conjunction with other neoplasms exhibit different immunophenotypes compared to pure MCC cases. We present a case of CK20-/TTF-1+ MCC concurrent with Bowen disease and BCC, and discuss possible differences in the pathogenesis of pure vs combined MCC. We also review the literature for this unusual immunophenotype, noting that most cases occur in combined MCC.

Cutaneous neoplasms composed of melanoma and carcinoma: A rare but important diagnostic pitfall and review of the literature

We report two cases of combined cutaneous tumors composed of melanoma and carcinoma. The first tumor presented as a 5-mm pink-blue macule over the right zygomatic arch in an 85-year-old man. Shave biopsy and immunohistochemical studies revealed that the tumor was composed of melanoma (highlighted by SOX10 and MART-1, with high Ki-67 proliferative index) intermixed with nodular basal cell carcinoma (highlighted by pan-cytokeratin and Ber-EP4). The neoplastic melanocytes were confined to the basal cell carcinoma nodules, and a diagnosis of combined melanoma in situ and basal cell carcinoma was rendered. After therapeutic excision, the patient was disease-free at 9 months after the initial diagnosis. The second tumor presented as a 6-mm pink-brown crusted papule on the right forehead in an 89-year-old man. Shave biopsy and immunohistochemical studies revealed that the tumor was composed of malignant melanoma (MM) (highlighted by S100 and MART-1) intermixed with squamous cell carcinoma (SCC) (highlighted by cytokeratin and p63), and a diagnosis of combined MM-SCC was rendered. These two cases highlight the importance of recognizing these rare types of melanocytic-epithelial cutaneous neoplasms to arrive at an accurate diagnosis that may inform appropriate disease stage and therapy.

Combined Mucinous and Neuroendocrine Tumours of the Appendix Managed with Surgical Cytoreduction and Oxaliplatin-based Hyperthermic Intraperitoneal Chemotherapy

Appendiceal neoplasms account for 1% of appendectomy specimens. Common subtypes include mucinous cystadenoma, adenocarcinoma, and neuroendocrine tumors (NETs). The simultaneous presence of appendicular mucinous and NETs is a rare event. Depending on the tumors’ morphological distribution in the affected organ, they are qualified as either “collision” or “combined” tumours. We herein present the case of a 50-year-old male who presented with acute appendicitis and who was subsequently found to have pseudomyxoma peritonei (PMP) due to a perforated combined mucinous and neuroendocrine tumours. The patient was treated by right hemicolectomy and cytoreductive surgery (CRS) with oxaliplatin-based hyperthermic intraperitoneal chemotherapy (HIPEC). He was cancer free 20 months later. Due to the limited clinical experience with this presentation, no formal recommendations exist as to its management other than those applicable to each cancer alone. The efficacity of treatment on the long-term prognosis on these combined tumors is yet to be elucidated.

High-Risk BCC Of the Lower Eyelid in Patient with Presternal Located Cutaneous Melanoma and BCC Of the Shoulder: Melolabial Advancement Flap Combined with Undermining Surgical Approach As Promising Complex One Step Treatment Option!

BACKGROUND:

It is assumed that the occurrence of keratinocyte and melanocytic tumours is multifactorial driven. Certain risk factors such as solar radiation, p53 protein and Melanocortin-1 receptor (MC1R) prove to be common to their development, which at the same time shows that their simultaneous manifestation in the same patients, for example, is quite possible. Such a manifestation could be observed as collision tumours within the same solitary lesion or as a simultaneous occurrence within two completely different lesions that are clearly distinguished from one another.

CASE REPORT:

An 85-year-old patient is presented with three primary cutaneous tumours located in region presternal, infraorbital sinistra and scapularis extra. The lesions were removed during a single surgical session. For the high-risk basal cell carcinoma (BCC) in the lower eyelid, the so-called melolabial advancement flap was applied, and for the tumours located in the other two areas, the undermining surgical approach was applied. The subsequent histological analysis found that the case referred to two keratinocyte tumours (BCC) and one melanocyte tumour (cutaneous melanoma).

CONCLUSIONS:

The patient presented is interesting with regard to 1) the simultaneous presentation of three primaries with different localization (so far not described in the world literature, namely 2 basal cell carcinomas and one melanoma in the same patient concurrently), 2) one of the basal cell tumours belongs to the group of high-risk (according to the localization) and meanwhile advanced BCC (according to the infiltration degree of the underlying tissue-infiltration of the musculature) and 3) their simultaneous successful surgical treatment in a single surgical session under local anaesthesia.

Basal cell carcinoma and malignant melanoma cutaneous collision tumor

Malignant tumors composed of both epithelial and melanocytic populations are exceedingly rare. Because the etiology of these malignant tumors is not yet defined, several authors have argued for the continued cataloging of these lesions. We present a 67-year-old man with a suspicious-appearing lesion on the right forearm; initial biopsy was consistent with a pigmented basal cell carcinoma. On re-excision, a collision of malignant melanoma and basal cell was identified.

Colliding, colonizing or combining? Four cases illustrating the unique challenges presented by melanoma arising in conjunction with basal cell carcinoma

Biphasic lesions comprised of melanocytic and epithelial components are rare entities believed to arise either as a collision of 2 histologically distinct lesions in the same anatomic location or as a singular progenitor tumor differentiating along 2 differing lineages. Regardless of mechanism of origin, these tumors present unique challenges in pathologic interpretation and in determining appropriate measurements, which assigns subsequent prognosis to the patient. We present 4 tumors of melanoma co-existing with basal cell carcinoma (BCC) and discuss relevant literature regarding these biphasic entities. Patients consisted of 3 males and 1 female, ranging in age from 62 to 93, with lesions located on the shoulder, frontal scalp, forearm and nose. Three of 4 lesions showed melanoma cells limited to BCC tumor lobules, without evidence of direct dermal invasion by melanoma cells, raising the question of whether or not these tumors should be classified as in situ or invasive melanoma. These cases highlight the complexity that such lesions pose to dermatopathologists, in terms of their uncertain origin and variable microscopic appearance. In the absence of data regarding outcomes for these tumors (given their rarity), it is important to utilize a case-by-case approach, with careful clinical correlation and appropriate use of ancillary techniques.

Pigmented squamous cell carcinoma: case report and importance of differential diagnosis

A few cases of pigmented squamous cell carcinoma affecting the skin and the ocular and oral mucosa of the elderly have been described in the literature. The disease manifests itself as papular and nodular erythematous or pigmented lesions. The main clinical differential diagnoses are pigmented basal cell carcinoma and melanoma. Histopathological examination is characterized by proliferation of atypical squamous cells with formation of horn pearls permeated by dendritic melanocytes. For this reason, a careful diagnosis is necessary to rule out other tumors that show melanin pigment. Surgical removal is the indicated treatment and the prognosis is similar to the classical squamous cell carcinoma. We report a case of pigmented squamous cell carcinoma with diagnosis confirmed by histological and immunohistochemical examinations.

Malignant collision tumors in two dogs

CASE DESCRIPTION A 13-year-old Labrador Retriever with a 4-cm-diameter ulcerated perianal mass and a 12-year-old Golden Retriever with a 5-cm-diameter ulcerated caudolateral abdominal mass were brought to a referral oncology practice for evaluation of the dermal masses. Both masses were resected with wide margins without reported postoperative complications. For both dogs, a diagnosis of collision tumor was made. The database of the Veterinary Diagnostic Laboratories at Colorado State University was searched for other examples of collision tumors in dogs. CLINICAL FINDINGS Histologic assessment of the masses revealed collision tumors in both patients. The perianal mass was diagnosed as a perianal gland carcinoma with adjacent hemangiosarcoma. The flank mass was diagnosed as a fibrosarcoma with an adjacent mast cell tumor. The university database search of sample submissions in 2008 through 2014 for the keywords collision, admixed, or adjacent yielded 37 additional cases of dogs with malignant nontesticular collision tumors. TREATMENT AND OUTCOME Both dogs were treated with surgery alone and received no adjunctive treatments. Both tumors were completely excised. There was no evidence of either local tumor recurrence or metastasis in the Labrador Retriever and the Golden Retriever at 1,009 and 433 days after surgery, respectively. CLINICAL RELEVANCE Collision tumors are rare, and there is minimal information regarding treatment recommendations and outcome for animals with collision tumors. On the basis of the 2 cases described in this report, the outcome associated with treatment of collision tumors may be similar to the expected outcome for treatment of any of the individual tumor types in dogs.

Collision skin lesions-results of a multicenter study of the International Dermoscopy Society (IDS)

Background

Collision lesions as two independent and unrelated skin tumors often manifest an atypical morphology.

Objective

To determine the combinations of collision skin lesions (CSLs).

Methods

Twenty-one pigmented lesion clinics in nine countries included 77 histopathologically proven CSLs in this retrospective observational study.

Results

Seventy-seven CSLs from 75 patients (median age 59.8 years) were analyzed; 24.7% of CSLs were located on the head and neck area, 5.2% on the upper extremities, 48.1% on the trunk, and 11.7% on the lower extremities; 40.3% revealed a melanocytic component (median age 54.7 years), followed by 45.5% with a basal cell carcinoma (BCC) (median age 62.4 years) and 11.7% with a seborrheic keratosis (median age 64.7 years). CSLs with a BCC component were more often found on the head and neck area compared to tumors with a melanocytic component (34.3% versus 16.1%). Lesions with a melanocytic component were more often detected on the trunk compared to lesions with a BCC (64.5% versus 37.1%). Patients with CSLs with epidermal-epidermal cell combination were older than patients with epidermal-dermal cell combination (63 versus 55.2 years), were more often male than female (63% versus 43.3%), more often had the lesion on the head and neck area (32.6% versus 13.3%), and less often on the upper (2.2 % versus 10%) or lower extremities (8.7% versus 16.6%).

Conclusions

CSLs consist of a heterogeneous group of lesions of varying cell types. They are associated with advancing age and cumulative UV-exposure. CSLs manifest a complex morphology making it challenging to diagnose correctly.

[Collision tumor]

A 65-year-old woman presented with a painless, partially pigmented and partially hyperkeratotic tumorous lesion on the lower eye lid. Histopathologic findings of the wedge resection showed a collision tumor of a highly differentiated squamous cell carcinoma and a fibrosing basal cell carcinoma. Collision tumors involving these two components are rare, particularly in the periocular region.

Oral Squamomelanocytic Tumour in a Dog: a Unique Biphasic Cancer

In human medicine, squamomelanocytic tumour is a malignant cutaneous neoplasm composed of closely intermingled neoplastic squamous cells and melanocytes. A multinodular gingival tumour in a 16-year-old, mixed breed neutered female dog was examined microscopically. Two populations of neoplastic cells, melanocytic and squamous epithelial cells were intermingled. The melanocytic cells were melan-A positive and cytokeratin AE1-AE3 negative and the squamous component was cytokeratin AE1-AE3 positive and melan-A negative. Bovine papillomavirus was not identified by immunohistochemistry or polymerase chain reaction. A diagnosis of squamomelanocytic tumour was made.

Melanoma in situ colonizing basal cell carcinoma: a case report and review of the literature

Colonization of basal cell carcinoma (BCC) by melanoma cells is a unique and uncommonly reported cutaneous entity. We describe a bluish nodule on the left forearm found during routine skin cancer surveillance examination with suspicious dermatoscopic findings including central-blue-white veil, sparse atypical dots, and a surrounding pink vascular blush with focal irregular tan-brown pigmentation at the periphery. Histopathology demonstrated a pigmented BCC with an overlying and adjacent melanoma in situ (MIS), as well as colonization of the BCC nodule by melanoma cells. We performed a review of the literature on the topic and discuss other presentations of cutaneous neoplasms composed of both BCC and melanoma, including collision, combined, and biphenotypic tumors. The prognostic and management challenges inherent to this distinctive neoplasm are summarized.

A colonization of basal cell carcinoma by malignant melanoma in situ resembling a malignant basomelanocytic tumor

We report a case of colonization of basal cell carcinoma (BCC) by malignant melanoma in situ (MIS) simulating a malignant basomelanocytic tumor. A biopsy of a pigmented lesion present on an 83-year-old man's scalp displayed intimate admixing of basaloid and melanocytic cells. This seemingly inseparable combination of BCC and neoplastic melanocytes has been referred to as a malignant basomelanocytic tumor. However, our case also displays an adjacent component of MIS, thus favoring colonization of BCC by MIS as the etiology. To our knowledge, this is the third case report of colonization of BCC by MIS resembling a malignant basomelanocytic tumor.

Clinical, dermoscopic and histological features of a combined tumor composed of a melanoma in situ, a basal cell carcinoma and an intradermal naevus

The combined tumors are neoplasms consisting of 2 or more distinct cell population that are intimately admixed. The presence of more than one neoplasm in the same lesion comprising melanocytes and keratinocytes are rare but well documented. We report a case of a 65-year-old man with a melanoma in situ, a basal cell carcinoma and an intradermal naevus in collision that clinically appeared as a single lesion. Clinical, dermoscopic and histological features are discussed.