Biphasic sarcomatoid basal cell carcinoma (carcinosarcoma): four cases with immunohistochemistry and review of the literature

Basal cell carcinosarcoma: a systematic review and reappraisal of its challenges and the role of Mohs surgery

Basal cell carcinosarcoma (BCCS) is a rare malignant biphasic tumor of the skin, composed of epithelial and mesenchymal components, and may be underdiagnosed. We sought to summarize the current understanding of BCCS including its reported history, clinical presentation, diagnosis, and treatment. We also reappraise and present our recommendations of histological interpretation for its diagnosis and treatment. A systematic review of PubMed and EMBASE, from inception of databases to December 1, 2022, identified all reported cases of basal cell carcinosarcoma. A total of 34 reports containing 54 patients with basal cell carcinosarcoma were included. The neoplasm was most commonly associated in areas of sun-exposed skin and primarily affected the elderly. Diagnosis was made on histology specimens using H&E. To address underdiagnosis, additional immunohistochemical markers have been proposed due to unreliable phenotypic appearance in this poorly differentiated neoplasm. Treatment consists of excision of the tumor, typically with Mohs surgery, and is curative in most cases. There are limited treatment options for metastatic disease. There were limitations to this study as various immunohistochemical stains used on suspected BCCS without providing an explanation as to why certain markers were included and others were excluded. Continued efforts in characterizing this complex neoplasm are critical in establishing reliable and accurate diagnostic tests and accompanying treatment options, especially in cases of metastatic disease.

When to sweat: A history of chemotherapy in malignant sweat gland tumors. A unique case report and literature review

Sarcomatoid sweat gland carcinomas are rare among cutaneous cancers, with less than 20 cases described. A 54-year-old woman with sarcomatoid sweat gland carcinoma of the right upper extremity suffered extensive recurrence at 15 months, unresponsive to chemotherapy. There is no standard treatment or chemotherapy regimens for metastatic sweat gland carcinoma.

An Unexpected Transformation: Malignant Spindle Cell Carcinoma Developed From Primary Basal Cell Carcinoma

Spindle cell carcinoma (SpCC)/sarcomatoid carcinoma is a biphasic tumor with molecular and histopathological properties of both epithelial and mesenchymal tumors. SpCC usually occurs either in sun-exposed areas like the head, neck, upper extremities, and chest or in the areas of skin with prior radiation exposure or in immuno-suppressed individuals. Cutaneous SpCC is a very rare disease, with only a handful of reported cases so far. SpCC differs from conventional squamous cell carcinoma (SCC) with dermal infiltration of atypical keratinocytes as single cells with hyperchromatic eosinophilic cytoplasm and elongated, pleomorphic nuclei with multiple nucleoli, in contrast to cohesive nests or islands in SCC. The objective of this study is to complete a review of the current literature and present a rare manifestation of malignant SpCC which developed from a localized basal cell carcinoma following excision and radiation therapy (RT) in a 79-year-old female. We plan to elucidate the importance of a timely and accurate diagnosis of this disease in order to maximize treatment options and improve survival outcomes.

Pilomatrical carcinosarcoma in the very elderly: A case report

Pilomatrical carcinosarcomas are very rare tumors. To the best of our knowledge, only nine cases diagnosed with pilomatrical carcinosarcomas have been reported. The present study reported on a case of pilomatrical carcinosarcoma in the posterior part of the left auricle of a 100-year-old male patient. The tumor histologically comprised the following two components: Pilomatrical carcinoma and undifferentiated spindle cell sarcoma. The pilomatrical carcinoma comprised atypical basaloid cells and shadow cells. The basaloid cells had basophilic cytoplasm, clear nucleoli and deeply stained nuclear chromatin. The undifferentiated spindle cell sarcoma comprised atypical spindle cells. Both components contained numerous mitotic cells. The boundary area between the carcinoma and sarcoma smoothly transitioned into each other. The carcinoma cells and a portion of the sarcoma cells were positive for β-catenin in the cytoplasm with or without the nuclei. These results suggested that the two components developed from the same origin.

Trichoblastic carcinosarcoma in a 34-year-old woman with histopathologic and molecular analysis, including re-demonstration of a CDKN2A p.(R58*) mutation

Trichoblastic carcinosarcomas are rare, adnexal-type cutaneous carcinosarcomas that are thought to be related histogenetically to trichoblastomas, yet in which both the epithelial and stromal components show features of malignancy. Ten cases have been described in the literature thus far, with a predilection for the head and neck of older males. We present a case of cutaneous carcinosarcoma in sun-damaged skin of a 34-year-old woman showing features of a trichoblastic carcinosarcoma, with histopathologic analysis along with targeted next-generation sequencing of 50 cancer-associated genes. Two pathogenic variants in TP53 were identified, p.(R158C), p.(R273P), along with a likely pathogenic variant CDKN2A, p.(R58*). In particular, it is noted that the CDKN2A p.(R58*) missense mutation has been described in two previous cases of cutaneous carcinosarcomas, including a case of trichoblastic carcinosarcoma.

Cutaneous Carcinosarcoma: A Small Case Series and Review of the Literature of a Rare Skin Tumor

Carcinosarcomas are composed of epithelial and mesenchymal elements and primarily present within visceral organs. Despite being potentially aggressive, they are a rare diagnosis in the skin, and few manifestations have been reported to date. In this report, we describe two separate cases of carcinosarcoma presenting as nonhealing scalp wounds. Patient A: a 57-year-old male with a nonhealing skin lesion of ten years successfully treated with wide-local excision and local ortichochea flap reconstruction. Patient B: a 75-year-old female that presented with a painless, slow-growing hemorrhagic mass of 7 years invading the skull and dura ultimately requiring craniectomy and free-tissue transfer with anterolateral thigh flap. Cutaneous carcinosarcomas have more favorable outcomes due to low metastatic rates likely due to earlier detection, but delayed presentation can be fatal. Histopathological analysis is critical for determining diagnosis and prognosis. Adequate reconstruction after wide base excision varies and follows the reconstructive ladder/elevator ranging from primary closure up through free-tissue transfer. With cutaneous manifestations of carcinosarcoma seldom reported in the literature, it is our hope that reporting unusual instances such as this will raise awareness and allow for earlier diagnoses, treatments, and reconstructions.

Primary cutaneous carcinosarcoma: clinical, histological, and immunohistochemical analysis of eight cases

BACKGROUND

Cutaneous carcinosarcoma is a rare biphasic tumor comprising malignant epithelial and heterologous mesenchymal elements. Data on the clinical and histopathologic characteristics of this tumor are scarce. The objective of this study was to describe the clinicopathologic and immunohistochemical features of cutaneous carcinosarcoma.

METHODS

A descriptive retrospective study was conducted in a tertiary care hospital from Spain. We reviewed the records of eight patients with cutaneous carcinosarcoma who were diagnosed from 2009 to 2019.

RESULTS

The mean patient age at diagnosis was 72.13 years (range 44-91 years), and there was a male predilection (6 cases). The most common site of cutaneous carcinosarcoma was the head and neck (5 cases). Carcinosarcomas demonstrated variable histopathological and immunohistochemical features. Follow-up was available for 7-8 patients. There were two cases of local recurrence and one case of metastasis. Two patients died from the tumor during the entire follow-up.

CONCLUSIONS

Although the number of cases in this study was limited, our results provide valuable insight into the clinical, histopathologic, and immunohistochemical characteristics of primary cutaneous carcinosarcoma.

A spindle cell squamous cell carcinoma on the cheek presenting with in-transit metastases and a satellite lesion

Spindle cell squamous cell carcinoma (SpSCC) is a biphasic tumor composed of squamous cell epithelial and spindle cell mesenchymal components, both of which are malignant. Cutaneous SpSCC can cause diagnostic and therapeutic difficulties because of its rarity, heterogeneity, morphological similarity to other cutaneous spindle cell neoplasms, and uncertain pathogenesis and prognosis, particularly when the squamous cell carcinoma component is minimal or missing. Intransit metastasis and satellite lesion (satellitosis) constitute a spectrum of non-nodal regional metastases. Here the author reports the first known case of cutaneous SpSCC presenting with intransit metastases and a satellite lesion, which were exceptionally aggressive. A 77-year-old female patient presented with a 3× 3× 0.5 cm mass on her right cheek. Despite wide excision and postoperative radiation, the patient resulted in local recurrence and multiple distant metastases within 3 months. If many high-risk factors-particularly satellitosis and in-transit metastases are observed in a tumor with epithelial to mesenchymal transition, then further wide excision and adjuvant chemoradiation should be considered early in the treatment process. A multidisciplinary approach could be the key to cure the most aggressive malignancies of the skin, as in other organs.

Trichoblastic Carcinosarcoma of the Skin: A Case Report and Literature Review

An 83-year-old man presented to the dermatology department for an ulcerated skin lesion of the back that had been increasing in size during the past 11 years. The physical examination revealed a well-defined, fleshy, reddish plaque measuring 10 × 20 cm in diameter with erosions and black areas on the surface. The patient underwent surgical excision with margins of 10 mm followed by a skin graft. Histologic section showed a lesion composed of 2 intimately intermingled epithelial and mesenchymal components associated with a basal cell carcinoma (BCC). Immunohistochemical examination showed epithelial cells that were positive for CK AE1/AE3 and p53, whereas stromal cells were positive for vimentin, CD10, and p53. BCC was positive for CD10. On the basis of these findings, a diagnosis of trichoblastic carcinosarcoma associated with BCC was made. Given the scarcity of data available in the literature regarding this diagnosis, no standard of care exists. No adjuvant treatment was provided and after 1 year of follow-up, the patient did not experience recurrence.

Cutaneous Carcinosarcoma: a Clinicopathologic and Immunohistochemical Analysis of 11 Korean Cases

BACKGROUND

Cutaneous carcinosarcoma is a rare biphasic tumor comprising malignant epithelial and heterologous mesenchymal elements. Data on the clinical and histopathologic characteristics of this tumor in Asian populations are not available. The purpose of this study was to investigate the clinicopathologic and immunohistochemical features of cutaneous carcinosarcoma in the Korean population.

METHODS

We retrospectively reviewed the records of 11 patients with cutaneous carcinosarcoma who were diagnosed from 2006 to 2016.

RESULTS

The mean patient age at diagnosis was 71.5 years (range, 43-96 years) and there was a men predilection. The most common site of cutaneous carcinosarcoma was the head and neck (8/11, 72.7%). Histopathologically, most tumors showed a characteristic morphology consisting of two types of tumor cells, varied differentiated epithelial cells (such as basal or squamous cells) and spindle cells with transition zones between the two components. These two cell types also demonstrated variable immunohistochemical characteristics.

CONCLUSION

Although the number of cases in this study was limited, our results provide valuable insight into the clinical and histopathologic characteristics of cutaneous carcinosarcoma in the Korean population.

A Case of Primary Cutaneous Basal Cell Carcinosarcoma

A 94-year-old man consulted our hospital due to a rapidly growing tumor on the left cheek. The histological diagnosis of the tumor was basal cell carcinosarcoma, which was composed of intermingled epithelial and mesenchymal components. The former was basal cell carcinoma, while the latter was spindle cell sarcoma. The tumor was completely resected with a 3-mm margin and the patient remained free of local recurrence or distinct metastasis for 2 years. We report here a case of cutaneous basal cell carcinosarcoma and a review of the literature.

Cutaneous Metaplastic Carcinoma: Report of a Case With Sebaceous Differentiation

In this study, a case of a 56-year-old woman with cutaneous metaplastic carcinoma in the neck is reported. It harbored basal cell carcinoma, squamous cell carcinoma, and sebaceous carcinoma, as well as osteosarcoma (with fibroblastic, osteoblastic, aneurysmal bone cyst-like, and chondroblastic patterns). To our knowledge, the literature does not mention sebaceous carcinoma in cutaneous metaplastic carcinoma. Epidemiology and intact mismatch repair proteins of this case support sporadic pathogenesis for this neoplasm. The patient has been followed up for 3 years after surgery with free margins, and no local recurrence or distant metastases have been observed.

Lung Sarcomatoid Carcinoma Metastasis to Skin: A Case Report and Review of the Literature

Sarcomatoid carcinoma is a biphasic neoplasm composed of highly complex, intimately admixed malignant epithelial and mesenchymal elements. We herein report a rare case of cutaneous metastasis of pulmonary sarcomatoid carcinoma that contains liposarcomatous, rhabdosarcomatous and chondrosarcomatous heterologous differentiation, and review relevant literatures to lead to a better understanding of this rare but highly aggressive tumor.

Cutaneous basal cell carcinosarcomas: evidence of clonality and recurrent chromosomal losses

Cutaneous carcinosarcomas are heterogeneous group of tumors composed of malignant epithelial and mesenchymal components. Although mutation analyses have identified clonal changes between these morphologically disparate components in some subtypes of cutaneous carcinosarcoma, few cases have been analyzed thus far. To our knowledge, copy number variations (CNVs) and copy-neutral loss of heterozygosity (CN-LOH) have not been investigated in cutaneous carcinosarcomas. We analyzed 4 carcinosarcomas with basal cell carcinoma and osteosarcomatous components for CNVs/CN-LOH by comparative genomic hybridization/single-nucleotide polymorphism array, TP53 hot spot mutations by polymerase chain reaction and Sanger sequencing, and TP53 genomic rearrangements by fluorescence in situ hybridization. All tumors displayed multiple CNV/CN-LOH events (median, 7.5 per tumor). Three of 4 tumors displayed similar CNV/CN-LOH patterns between the epithelial and mesenchymal components within each tumor, supporting a common clonal origin. Recurrent changes included allelic loss at 9p21 (CDKN2A), 9q (PTCH1), and 17p (TP53). Allelic losses of chromosome 16 including CDH1 (E-cadherin) were present in 2 tumors and were restricted to the sarcomatous component. TP53 mutation analysis revealed an R248L mutation in both epithelial and mesenchymal components of 1 tumor. No TP53 rearrangements were identified. Our findings indicate that basal cell carcinosarcomas harbor CNV/CN-LOH changes similar to conventional basal cell carcinoma, with additional changes including recurrent 9p21 losses and a relatively high burden of copy number changes. In addition, most cutaneous carcinosarcomas show evidence of clonality between epithelial and mesenchymal components.

Cutaneous carcinosarcoma with metastasis to the parotid gland

Cutaneous carcinosarcoma is a rare malignancy that exhibits both mesenchymal and epithelial components. It is similar to nonmelanoma skin cancers in terms of risk and prognostic factors. However, these malignancies are known to have a propensity for local recurrence and metastasis, even with adequate resection margins. Here we report a case of metastatic cutaneous carcinosarcoma to the parotid gland and review the relevant literature.

An unusual infiltrative basal cell carcinoma with osteoclastic stromal changes mimicking carcinosarcoma: a case report

A 91-year-old man presented with an ulcerated nodule on his left lower eyelid. The tumor showed an epithelial component composed of basaloid and clear cells and a stroma that contained many osteoclastic giant cells. Strong, diffuse expression for cytokeratin 17 and p63 was noted in the epithelial component, whereas no staining was present in the sarcomatoid stroma, suggesting that the osteoclast-rich stromal component represented an unusual benign stromal reaction to the carcinoma rather than a manifestation of carcinosarcoma. Further supporting this interpretation was the absence of mitotic figures and low Ki-67 proliferation index (of approximately 1%) in the stromal cells. We herein reported a case of unusual infiltrative basal cell carcinoma, accompanied by a clear cell carcinomatous features and concurrent benign osteoclastic stromal changes.

Primary cutaneous carcinosarcoma: insights into its clonal origin and mutational pattern expression analysis through next-generation sequencing

Primary cutaneous carcinosarcoma is a rare biphenotypic neoplasm exhibiting both epithelial and sarcomatous elements. Even though its origin and biological aspects remain poorly understood, it has been postulated that this tumor may arise from progenitor cells, which subsequently differentiate into distinct tumor components. We have investigated the histological and immunohistochemical staining patterns of a cutaneous carcinosarcoma case, as well as its ultrastructural aspects. In addition, sarcomatous and epithelial tumor components were separated by laser capture microdissection and subjected to targeted, high-depth, next-generation sequencing of a 46-cancer gene panel to asses the gene mutational pattern amongst both components. There were transitional cells at the epithelial/mesenchymal transition that labeled with putative progenitor cell markers (K19, c-kit, CD34 and Bcl-2). There was shared reactivity to antibodies directed against the progenitor cell marker EpCAM (epithelial cell adhesion molecule) in both components. Ultrastructurally, individual cells were demonstrated to have overlapping features of epithelial and mesenchymal differentiation. The mutational analysis revealed point mutations in exon 5 of TP53, which were identical in both the epithelial and sarcomatous components, and which were concordant with p53 expression at a tissue level. The aforementioned histological, ultrastructural, immunohistochemical and mutational pattern is strongly suggestive of a common clonal origin to the distinct elements of this tumor.

Morphologic manifestations of gene-specific molecular alterations ("genetic addictions") in mouse models of disease

Neoplasia in both animals and humans results in part from lasting activation of tumor-promoting genes ("oncogenes") or diminished function of genes responsible for preventing neoplastic induction ("tumor suppressor genes"). The concept of "genetic addiction" has emerged to indicate that neoplastic cells cannot maintain a malignant phenotype without sustained genotypic abnormalities related to aberrant activity of oncogene(s) and/or inactivity of tumor suppressor gene(s). Interestingly, some genetic abnormalities reliably produce distinct morphologic patterns that can be used as structural signatures indicating the presence of a specific molecular alteration. Examples of such consistent genetic/microanatomic pairings have been identified for mutated oncogenes, such as rising mucin-producing capacity with RAS overexpression, and mutated tumor suppressor genes-including PTEN eliciting cell hypertrophy, RB1 dictating neuroendocrine differentiation, and TRP53 encouraging sarcomatous transformation. Familiarity with the concept of genetic addiction, as well as the ability to recognize such regular genomic-phenotypic relationships, are of paramount importance for comparative pathologists who are engaged in phenotyping genetically engineered mice to help unravel genomic intricacies in both health and disease.

Study of D2-40 immunoexpression of the spindle cell areas of a metaplastic basal cell carcinoma (sarcomatoid basal cell carcinoma)

Sarcomatoid basal cell carcinoma (BCC) is rare. In the literature, data on the prognosis of such a variant is somewhat contradictory. D2-40 immunoexpression has been shown to have prognostic connotations in carcinomas of organs other than the skin. However, although D2-40 immunoexpression has been investigated in "common" (nonsarcomatoid) BCC, it has not yet been studied in the spindle cell component of a sarcomatoid BCC. We present a sarcomatoid BCC on the neck of an 87-year-old man that has grown rapidly over the last few months. The sarcomatoid component of the tumor expressed several types of cytokeratins, such as AE1/AE3, CK 5/6, 34betaE12, and CAM 5.2. It was also positive for p63 and for D2-40 in a diffuse pattern.

Primary retroperitoneal carcinosarcoma in a child: a case report

Carcinosarcoma is a rare biphasic malignancy consisting of intermixed epithelial and mesenchymal elements. Carcinosarcoma is particularly rare among children. We accepted a 7 year old patient with retroperitoneal carcinosarcoma. The tumor was totally resected and no recurrence is found 11 months after operation. Literatures has been reviewed and there are few reports of primary retroperitoneal carcinosarcoma in children up to date. So we report the patient's clinical character, surgical resection, pathological and immunohistochemical analysis.

Cutaneous sarcomatoid carcinoma with features of giant cell tumor of soft parts--a case report

We report here a previously undescribed tumor in a 72-year-old patient who had a nasal cutaneous sarcomatoid carcinoma. The epithelial component resembles a skin adnexal tumor, and the sarcomatous component resembles a giant cell tumor of soft parts.

p63 in Primary Cutaneous Carcinosarcoma

Primary cutaneous carcinosarcomas (PCCs) are rare malignant neoplasms that are characterized by biphasic epithelial and mesenchymal differentiation. When the biphasic nature is not evident, immunohistochemical studies may be important in the diagnosis of PCCs. Although AE1/AE3 is frequently used to demonstrate the epithelial component, it may not be strongly expressed in epithelial cells that are not well-differentiated. p63 is a protein homologue of p53 that is expressed in poorly differentiated epithelial cells. We report 3 cases of PCC. The clearly epithelial areas of each tumor were frequently positive for both markers, whereas the sarcomatous areas were negative for both markers. Epithelial cells that were poorly differentiated and not easily identifiable were positive for p63 but negative for AE1/AE3. Of interest, transitional areas showed positivity for p63 alone. These 3 cases suggest that the use of both p63 and routine cytokeratin markers such as AE1/AE3 can increase the sensitivity for distinguishing epithelial cells over a range of differentiation states, which we propose will aid in the diagnosis of PCCs. In addition, the staining pattern of AE1/AE3 and p63 in these cases further supports the conversion theory of PCC.

Primary Cutaneous Metaplastic Carcinoma: Report of a Case Involving Angiosarcoma

Primary cutaneous metaplastic carcinoma is an uncommon cutaneous malignancy comprising a mixture of epithelial and mesenchymal components. The former is most frequently a squamous cell or basal cell carcinoma, and the latter is most typically a pleomorphic sarcoma or atypical fibroxanthoma. We describe the first primary cutaneous metaplastic carcinoma with angiosarcoma as the mesenchymal component arising on the scalp of a 90-year-old woman.

Trichoblastic sarcoma: a high-grade stromal tumor arising in trichoblastoma

We report a case of primary sarcoma of the skin with a biphasic histological pattern, being composed of areas of mixed mesenchymal-epithelial cell proliferation and areas of purely sarcomatous growth. The tumor occurred in the posterior cervical region of a 93-year-old man, and its history was marked by sudden, rapid enlargement after many years of stable duration. The excised lesion was about 4 cm in diameter, had a firm consistency and was covered by intact skin. Histological examination showed a multifocal proliferation of follicular germinative cells arranged in corymbiform and petaloid shapes with an overall retiform growth pattern. Epithelial cords and strands were composed of cytologically uniform cells with bland nuclear features and were surrounded by a prominent, fibroblast-rich stroma reminiscent of a perifollicular sheath. In many areas of the tumor the stroma showed abrupt transition into a pleomorphic proliferation of large sarcomatous cells with frequent and often atypical mitoses. Multinucleated neoplastic cells infiltrated the epithelial structures to cause their partial or total obliteration in many fields of the lesion. Immunohistochemically, the epithelial cells displayed expression of various keratins, with a particularly intense staining for 34betaE12, and were partly positive for the CD10 antigen. A strong immunostaining for this antigen was also observed in malignant-appearing stromal areas, where no expression of cytokeratins was detected. Moreover, nuclear positivity for p53 protein was seen in sarcomatous cells, whereas it resulted in total lack of epithelial elements. Our case emphasizes that high-grade sarcoma may occur in the spectrum of trichoblastic tumors and that it may share some features of other noncutaneous biphasic neoplasms, such as mammary cystosarcoma phyllodes.

Sarcomatoid Basal Cell Carcinoma—Predilection for Osteosarcomatous Differentiation

Primary cutaneous carcinomas rarely show heterologous malignant mesenchymal differentiation. We report 11 cases of sarcomatoid basal cell carcinoma (BCC) with osteosarcomatous differentiation. The patients (7 men and 4 women) ranged in age from 61 to 92 years (median 75 y). The tumors presented as exophytic nodules (0.3 to 7 cm) on the head (n=6), upper limb (n=3), and lower limb (n=2). All lesions were completely excised. Seven patients were alive without evidence of disease (follow-up interval 5 to 24 mo) and 1 patient died of unrelated causes at 7 months without evidence of disease. On histology, the tumors were dermal in location with 2 cases showing focal subcutaneous involvement. Ten tumors were well-circumscribed and 1 tumor showed focally infiltrative edges. Ten tumors revealed conventional BCC associated with varying proportions of osteosarcomatous and undifferentiated sarcomatous stroma. Transition from neoplastic epithelial to mesenchymal cells was seen in 8 cases. One case showed a purely osteoclastic giant cell rich malignant mesenchyme, interpreted as representing early stages of osteosarcomatous transformation. Previously unreported in sarcomatoid BCC, the mesenchymal component of another two cases displayed predominant malignant giant cell tumor like areas and 1 further case disclosed areas reminiscent of telangiectatic osteosarcoma. Pancytokeratins (AE1/3 and MNF116) and smooth muscle actin stained occasional undifferentiated sarcomatous cells in 2 and 3 tumors, respectively. MNF116 and EMA were focally positive in osteosarcomatous tumor cells of 1 case. Although the follow-up interval is short, our data suggest an excellent prognosis for polypoid and exophytic sarcomatoid BCC after complete surgical resection.

Pleomorphic Basal Cell Carcinoma: Case Reports and Review

Pleomorphic basal cell carcinoma is a pathologic variant of basal cell carcinoma characterized by the presence of atypical-appearing, mononuclear or multinucleated giant cells. Including our 3 patients, a total of 52 pleomorphic basal cell carcinomas have been described in 48 individuals. The tumors usually present as a nodule on the head or neck. The nuclei of the giant tumor cells are irregularly shaped, hyperchromatic, and 2 to 10 times larger than the nuclei of the surrounding cancer cells. Atypical mitoses may be present. The pathogenesis of pleomorphic basal cell carcinoma remains to be determined; however, investigations utilizing electron microscopy, immunohistochemistry, image analysis, and flow cytometry have provided additional insight regarding the features of the giant tumor cells and the etiology of this cancer. All of these tumors are aneuploid. Although these aneuploid tumors have alarming microscopic features, their clinical course is similar to that of basal cell carcinomas without pleomorphic giant tumor cells. Therefore, appropriate therapy to ensure adequate treatment of the tumor is recommended. Our patients' pleomorphic basal cell carcinomas were successfully treated by excision using the Mohs micrographic surgical technique.

Primary cutaneous carcinosarcoma arising in a patient with nevoid basal cell carcinoma syndrome

BACKGROUND

Nevoid basal cell carcinoma syndrome (NBCC) is an autosomal dominant disorder characterized by developmental abnormalities and neoplasms including basal cell carcinoma (BCC) and sarcomas (i.e. leiomyosarcoma, rhabdomyosarcoma, and fibrosarcoma). Primary cutaneous carcinosarcoma (PCC), a rare tumor composed of malignant epithelial and mesenchymal components, has never been previously described in association with this syndrome.

CASE REPORT

A 61-year-old Hispanic man with a history of NBCC presented with a 4 cm nodule on the right proximal medial thigh. PATHOLOGIC FINDINGS: Areas of typical BCC merged with intersecting fascicles of large atypical spindle cells that stained for vimentin and were negative for actin, desmin, CD-34, and S-100 protein. Scattered bizarre solitary cytokeratin-positive epithelioid cells were embedded within the fibrocytic proliferation.

CONCLUSIONS

Several carcinosarcomas have been reported to contain BCC as the malignant epithelial component, but to our knowledge, this is the first report of PCC associated with NBCC. Mutation in patched tumor suppressor gene on chromosome 9q occurs in BCCs of NBCC, and aberrancies on chromosome 9q are also reported in some carcinosarcomas. It is possible that the known genetic defect on chromosome 9 in this patient contributed to the development of carcinosarcoma. Bhattacharjee P, Leffell D, McNiff JM. Primary cutaneous carcinosarcoma arising in a patient with nevoid basal cell carcinoma syndrome.