Collision tumor of cutaneous malignant melanoma and basal cell carcinoma

Collision tumor of malignant tumors of the skin: dermal squamomelanocytic tumor coexisting with basal cell carcinoma-a rare case

Collision tumors are neoplasms coexisting in the some anatomical area. The most common combination is melanocytic nevus with basal cell carcinoma. Melanocytic nevus with basal cell carcinoma constitutes the most common cutaneous combination. Co-existence of two malignant neoplasms is extremely rare. We describe the case of a 69-year-old man who was admitted to our hospital with a nodular mass on the back. We performed an excisional biopsy that revealed collision tumor, consisting of basal cell carcinoma along with mixed melanosquamous carcinoma. Subsequently, wide excision with sentinel node biopsy was performed. The sentinel node was negative. The patient did not receive any ongologic therapy.

Basal cell carcinoma and squamous cell carcinoma in a single tumor in the anterior auricular area

The concurrence of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) in a single tumor is rarely encountered. We report a case of BCC and SCC in a single tumor in the anterior auricular area. A 70-year-old woman had been diagnosed with BCC by a punch biopsy performed at a dermatology clinic. We performed wide excision of the tumor with an ulcer in the anterior auricular area. Analysis of the biopsy specimen revealed the presence of both BCC and SCC in the tumor. This case illustrates that it is necessary to establish a precise diagnosis and formulate appropriate surgical and treatment plans considering the possibility that two carcinomas may coexist, although the possibility is low in patients with skin cancer.

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.

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.

Collision of malignant neoplasms of the skin: basosquamous cell carcinoma associated with melanoma

Collision tumors are characterized by the coexistence of two cancers in the same anatomical site and its pathogenesis remains controversial. Although uncommon, the association of basal cell carcinoma and melanocytic nevus is the most common among combinations of skin tumors. Even rarer is the association of two malignant tumors. We report a case of tumor collision representing melanoma and basosquamous cell carcinoma, a combination not previously described in the literature, since there are no reported cases of melanoma with this type of basal cell carcinoma.

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.

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

We report a case of a very unusual combined and collision basosquamous melanocytic malignant tumor on the chest of an 84-year-old man. To our knowledge, this is the first case report describing this entity. We attempt to address the diagnostic challenge and the clinical and histological characteristics of these rare neoplasms with a review of the English literature to further categorize and summarize what has been previously reported about these extraordinary tumors.

Recurrent lentigo maligna melanoma commingling the tumour nests of a basal cell carcinoma

There are various types and combinations of coexisting cutaneous neoplasms which have been documented in the past but are uncommon. In this report we describe a case of basal cell carcinoma (BCC) colonised by recurrent lentigo maligna melanoma. A review of the literature has established the coexistence of lentigo maligna and BCC in six cases. The unusual combination of melanoma and BCC poses a therapeutic and prognostic dilemma. BCC is known to have a favourable outcome whereas melanoma tends to behave in a more aggressive manner leading to a less favourable outcome. There are conflicting views as to whether these lesions should be treated as BCC's or lentigo maligna melanoma. Our case appears to be unique, in that it was a recurrent lentigo maligna melanoma which was colonising the BCC. We treated our patient with wide local excision and full thickness skin graft and will continue to observe him on an outpatient basis. There needs to be long term follow up of a larger number of patients for us to truly appreciate the biological significance of parasitism of BCC by lentigo maligna melanoma.

Unusual occurrence of a melanoma with intermixed epithelial component: a true melanocarcinoma?: case report and review of epithelial differentiation in melanoma by light microscopy and immunohistochemistry

We report a case of a 27-year-old woman with a nonpigmented lesion on the right scalp. Histological examination showed a malignant nodular neoplasm with 2 distinct but intimately admixed components: a malignant melanoma with a spindle component and an unusual glandular component. Immunohistochemical studies demonstrated epithelial differentiation on the basis of cytokeratin (CAM5.2 and AE1/AE3) expression in the glandular component and melanocytic differentiation (HMB-45, PNL2, MITF, and S-100) of the spindle cell component. A single melanocytic marker (MITF) was expressed in both components, raising the possibility of dual differentiation in a single tumor, rather than the alternative considerations of a collision tumor or a reactive pseudoepitheliomatous hyperplasia with eccrine duct lumen formation within a melanoma. This unusual tumor with both melanocytic and epithelial components may represent a true melanocarcinoma, which becomes a plausible consideration, in view of melanoma plasticity and recent experimental evidence and speculation about the role of stem cells in melanoma.

Combined malignant melanoma and basal cell carcinoma tumor of the intermingled type

BACKGROUND

The combination of malignant melanoma (MM) and basal cell carcinoma (BCC) within a single tumor is an unusual finding.

CASE REPORT

An 84-year-old white man with a pigmented tumor on the back showing a combination of MM and BCC.

RESULTS

A 1.5 x 1.5-cm irregular brown lesion on the back was clinically suggestive of MM. Histopathologically, the lesions turned out to be a combined tumor consisting of a superficial BCC and a regressive MM with a tumor thickness of 1.25 mm. The conglomerates of the BCC lay within the MM and were admixed with a high number of Melan-A-positive melanocytic cells.

CONCLUSION

By reviewing the low number of published cases, we found that a combined MM-BCC tumor exists in two variants: a collision type in which components of each cell type are clearly demarcated and an intermingled type in which both cell types grow intimately together. Although both types occur as a mere incidence, in particular, the intermingled type may be diagnostically challenging and the evaluation of its dignity may be questionable.

Primary invasive melanoma and basal cell carcinoma (collision tumor) with blue nevus-like cutaneous metastases

The simultaneous presence of two disparate neoplasms occurring in the same specimen has been well documented, albeit uncommonly. The juxtaposition of malignant melanoma and basal cell carcinoma (BCC) has been rarely reported in case reports, with most cases describing melanoma in situ and BCC. We present two cases of invasive melanoma (Clark level IV, no microscopic satellites present) intimately associated with BCC, and in areas distinction of the two lesions was difficult. Immunohistochemical studies delineated the two cell populations. In addition, one patient presented with multiple cutaneous metastases, all simulating blue nevi. The metastases occurred in the same anatomical region as the primary tumor, and histologically consisted of pigmented dendritic melanocytes and melanophages in the superficial and mid-dermis and arranged in a blue nevus-like lesion. Histologic clues suggesting the possibility of a metastatic melanoma included a sparse lymphocytic infiltrate, the presence of an epithelioid component and atypia of the dendritic melanocytes. However, without appropriate clinical history, the lesions could be overlooked as ordinary blue nevus. Collision tumors containing invasive melanoma and BCC are rare and this is the first report of a collision tumor with blue nevus-like metastasis. Awareness of this phenomenon and pattern of metastasis, together with the clinical findings will aid in the correct classification of these lesions.

Collision tumor of malignant skin cancers: a case of melanoma in basal cell carcinoma

The coexistence of two malignant skin tumors intermingling in the same histologic specimen is rare. We report a case of melanoma in a basal cell carcinoma collision tumor. The presence of two intermingled neoplasms was confirmed by immunohistochemistry, which showed strong positivity for S-100 and HMB-45. A review of the literature and a case analysis allow for some pathogenetic and prognostic considerations.

Contiguous lesions in lentigo maligna

BACKGROUND

Determining the best biopsy technique for a suspected lentigo maligna can be challenging. Because complete excisional biopsy is rarely practical, the physician is left to choose an appropriate area to biopsy. Sampling error can have devastating consequences, especially if the biopsy demonstrates a pigmented lesion that was considered in the clinical differential diagnosis. The presence of a solar lentigo, pigmented actinic keratosis, or reticulated seborrheic keratosis could mislead the pathologist and clinician to the erroneous conclusion that the incisional specimen is representative of the whole, and that no lentigo maligna is present.

OBJECTIVE

We have often observed the presence of a contiguous pigmented lesion adjacent to lentigo maligna. The current study was designed to determine how frequently this phenomenon occurs.

METHODS

We studied Mohs debulking specimens of lentigo maligna, and broad shave biopsy specimens of pigmented lesions on heavily sun-damaged areas of the skin proven to be lentigo maligna.

RESULTS

Contiguous pigmented lesions were present in 48% of the specimens. The most common lesion was a benign solar lentigo (30%), followed by pigmented actinic keratosis (24%).

CONCLUSION

Recognition of this phenomenon may prevent misdiagnosis of lentigo maligna related to sampling error.

A collision tumor involving Basal cell carcinoma and lentigo maligna melanoma

Basal cell carcinomas (BCC) are known to co-exist with other cutaneous lesions, but the collision of BCC with malignant melanoma is rare. We report on the case of an 82-year-old woman with a translucent papule set on a beige-brown plaque on the right side of the nose. Histologic examination showed lesions of lentigo maligna melanoma (LMM) in situ and invasive melanoma involving nests of BCC that invaded the dermis. Immunohistochemical studies with S100 protein, HMB-45, and Melan-A antibodies showed the melanocytic component in the epidermis and dense clusters of "atypical" melanocytes in the dermal nests of BCC. On examination of the biopsy specimen, melanoma was still in situ because it was limited to the nests of BCC and not detectable between dermal collagen bundles. However, the re-excision of the lesion showed residual BCC and invasive LMM, level II, measuring 0.2 mm in thickness. The diagnosis, pathogenesis, and prognosis of this collision tumor are discussed.

Collision tumor of apocrine carcinoma and squamous carcinoma occurring in the ear

An unusual case of a cutaneous collision tumor comprised of a squamous cell carcinoma and an apocrine carcinoma occurring in the auricle of an 82-year-old man is presented. Microscopic study confirmed 2 distinct tumors: a squamous cell carcinoma arising in the epidermis and an adjacent apocrine carcinoma. We discuss the diagnostic criteria and review pertinent recent literature. To our knowledge, this is the first English language report of such a collision tumor.

Parasitism of basal cell carcinoma by lentigo maligna melanoma

The coexistence of 2 types of malignant neoplasms is relatively uncommon. We report a pigmented melanocytic lesion occurring adjacent to a previously treated basal cell carcinoma. Histology showed melanoma (lentigo maligna type) colonizing basal cell carcinoma demonstrated by hematoxylin-eosin and immunocytochemistry stains. It is unclear whether this lesion has the metastatic potential of an invasive melanoma of similar thickness, or simply reflects melanoma in situ extending into an epidermal-derived tumor analogous to appendageal extension of lentigo maligna. We review the literature on melanoma colliding with basal cell carcinoma. Therapeutic and prognostic problems are posed by this unique situation.

Basal cell carcinomas are populated by melanocytes and Langerhans [correction of Langerhan's] cells

Several reports have documented the coexistence of basal cell carcinoma (BCC) with other lesions, including melanoma. This study was performed to determine whether nests of BCC contain benign melanocytes and Langerhans [corrected] cells. Ten cases of BCC were investigated to determine whether benign melanocytes and Langerhans [corrected] cells populate tumor nests. The BCCs were stained with antibodies to cytokeratin AEI/AE3, S-100, HMB-45, Melan-A, and CD1a proteins. We report that all 10 BCCs were populated by dendritic melanocytes distributed at the periphery (5/10 cases) or evenly throughout tumor nests (5/10 cases). Clusters of melanocytes were not identified in any of the BCCs. A total of 9 of 10 tumors showed staining of dendritic Langerhans cells with CD1a. A total of 8 of 10 tumors stained with cytokeratin AEI/AE3; in 6 of the 8 tumors, the staining was focal. We compared these findings with a single example of a BCC and melanoma in situ (MIS) collision tumor in which the cytokeratin AE1/AE3-positive epithelial nests of BCC were populated by a high density of malignant melanocytes that stained with S-100 and HMB-45. Melanocytes were disposed singly and in clusters of two or more cells within BCC tumor nests. We conclude from this study that BCCs are regularly populated by benign melanocytes and Langerhans [corrected] cells. Furthermore, when BCC is infiltrated with malignant melanocytes of MIS, the melanocyte density is higher and clusters of melanocytes can be observed. The significance of these two findings is unclear, as additional cases of BCC MIS collision tumor need to be studied.