Histologic patterns of basal cell carcinoma based upon patient immunostatus

Cross-Talk between Wnt and Hh Signaling Pathways in the Pathology of Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most frequently occurring form of all cancers. The cost of care for BCC is one of the highest for all cancers in the Medicare population in the United States. Activation of Hedgehog (Hh) signaling pathway appears to be a key driver of BCC development. Studies involving mouse models have provided evidence that activation of the glioma-associated oncogene (GLI) family of transcription factors is a key step in the initiation of the tumorigenic program leading to BCC. Activation of the Wnt pathway is also observed in BCCs. In addition, the Wnt signaling pathway has been shown to be required in Hh pathway-driven development of BCC in a mouse model. Cross-talks between Wnt and Hh pathways have been observed at different levels, yet the mechanisms of these cross-talks are not fully understood. In this review, we examine the mechanism of cross-talk between Wnt and Hh signaling in BCC development and its potential relevance for treatment. Recent studies have identified insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), a direct target of the Wnt/β-catenin signaling, as the factor that binds to GLI1 mRNA and upregulates its levels and activities. This mode of regulation of GLI1 appears important in BCC tumorigenesis and could be explored in the treatment of BCCs.

Macrophage subtypes in recurrent nodular basal cell carcinoma after Mohs micrographic surgery

BACKGROUND

The macrophages associated with solid tumors are related to the progression or regression of tumors, depending on the differentiation in M1 or M2. M2 subtype promotes angiogenesis, remodeling, and tissue repair (tumor proliferation). In contrast, M1 produces toxic mediators and presents antigens, destroying microorganisms and tumor cells. The microenvironment of most aggressive forms of basal cell carcinoma (BCC) shows an increase in macrophages due to M2 phenotype compared to noninvasive forms. The treatment of nodular BCC by Mohs micrographic surgery (MMS) provides high cure rates, but relapses can occur.

AIMS

To compare the total population of macrophages and their subpopulations M1 and M2 in cases of recurrent and nonrecurrent nodular BCC after excision by MMS.

MATERIALS & METHODS

Histological sections obtained from paraffin blocks of nine cases of recurrent nodular BCC after MMS and 18 cases of nonrecurrent nodular BCC operated by MMS were immunostained for iNOS, CD204, CD163, and CD68. The expression of these markers was analyzed by image analysis.

RESULTS

No significant differences were found between the groups in relation to the average percentage of M1 cells, M2 cells, and total cells.

DISCUSSION AND CONCLUSION

A relationship was not seen between tumor-associated macrophages (TAM) and tumor recurrence.

Coexistence of Solid (Nodular) and Differentiated (Adenoid) Basal Cell Carcinoma at the Same Anatomical Site

Coexistence of two different histopathological types of basal cell carcinomas (BCCs) in the same anatomical site is rare and interesting. Herein, we report a case of coexistence of nodular and adenoid BCC in a 78-year-old peasant who presented with a plaque and a globular swelling on left paranasal region of few years duration. Histopathology of skin biopsy with immunohistochemistry study using antibodies to S100, epithelial membrane antigen (EMA) and cytokeratin 7 (CK 7) from the margin of the ulcer and globular swelling confirmed the diagnosis that revealed features of nodular and adenoid basal cell carcinoma, respectively. Investigative work up did not reveal evidence of metastasis.

Proliferation Patterns Reflect Architectural Dedifferentiation: A Study of Nodular Basal Cell Carcinoma

The distribution of proliferating cells in basal cell carcinoma (BCC) may be related to lesion type and architecture. Single proliferation indexes may not be representative. We aimed to establish the distribution of cell proliferation in BCC as related to architecture. We studied an unselected, consecutive series of 45 resection specimens of nodular BCC from patients in the age range of 25-95 years using MIB-1 staining and systematically reviewed the cases. These lesions included nodular (n=32) and non-nodular (n=9) BCC. Within the nodular BCC, two patterns were recognised, not related to age or gender. In small nodular patterns with well developed peripheral palisading and central parallel streaming of small, elongated nuclei, proliferation is limited to the basal palisading cells in a clustered distribution. In large nodular patterns, proliferation is absent at the basal membrane (BM) and distributed in single random cells throughout the lesion. Both patterns preclude accurate quantitation. Many lesions contained both patterns in a side-by-side, unmixed manner. These pattern differences suggest a loss of differentiation in nodular BCC. Perhaps a single mutation results in the loss of BM associated cell architecture and proliferation control related to tumor-stroma interactions. As a result, the lesion reverts to a low frequency, non-regulated proliferation, diffusely distributed throughout the lesion. The two patterns may exist side-by-side in a single lesion, further supporting the concept of polyclonality. This hypothesis explains perilesional clefting and previously reported variations in intra-lesional laminin synthesis. Based on our findings, representation of tumor cell proliferation activity by a single value is not justified. Nodular BCC exists in one of two dedifferentiation-mutation-determined patterns of cell proliferation; many lesions clearly demonstrate bi-clonality.

Immunotherapy for cutaneous malignancy

BACKGROUND

Immunotherapy for cutaneous malignancy involves manipulating the immune system to treat and prevent skin cancer. Although initial efforts were fraught with low success rates and technical challenges, more-recent endeavors have yielded response rates approaching 50% for treating metastatic melanoma. Many of these advances are a result of increasing knowledge of the immune system's intricacies and continued progress in laboratory techniques.

OBJECTIVE

To review our current understanding of the skin immune system and discuss how these factors contribute to the host response to malignancy and to report the current state of immunotherapeutic techniques.

MATERIALS AND METHODS

An extensive PubMed literature search was conducted in topics involving immunotherapy with specific relevance to cutaneous malignancy using the MeSH terms "immunotherapy" and "skin cancer."

RESULTS

Despite initially poor patient responses to these treatment modalities, recent gains in scientific knowledge and clinical intervention protocols have brought immunotherapy to the forefront of prospective skin cancer therapeutics, particularly for advanced melanoma.

CONCLUSIONS

Current treatment options for advanced cutaneous malignancies such as melanoma are low in efficacy. Immunotherapies have the potential to provide novel approaches to address this, particularly when used in combination. The authors have indicated no significant interest with commercial supporters.

Micronodular basal cell carcinoma: a distinct subtype? Relationship with nodular and infiltrative basal cell carcinomas

Micronodular basal cell carcinoma (BCC) may be more difficult to eradicate and prone to recurrence than nodular subtype. The aim of the study was to compare anatomical and histological characteristics of the basal cell carcinomas subtypes and the relationship of the micronodular BCC with other subtypes. Primary BCCs (n = 3074) were classified as superficial, nodular, micronodular, morpheic/infiltrative. The location was head/neck, limbs, chest/abdomen, back or genitals. Fifty-one micronodular BCCs were matched randomly with nodular and infiltrative cases, by age, sex, and tumor site. A modified Clark level was used to classify the tumor depth. Micronodular, nodular and infiltrative BCC were prevalently located in the head/neck (P < 0.0001), while superficial in the other regions (P < 0.0001). The Clark level was comparable between micronodular and infiltrative BCC, while nodular BCC showed a more superficial level than micronodular (P < 0.001) and infiltrative (P < 0.001) BCC. No nodular BCC had level IV and only 37.3% level III, while 92% of both micronodular and infiltrative BCC were level III or IV. The percentage of level IV was 11.8% and 25.5% in micronodular and infiltrative BCC, respectively. In the mid-face/periauricular region, 95.5% of micronodular and 100% of infiltrative cases of were level III or IV, compared to 50% of nodular BCC (P < 0.001). The Clark level of nodular subtype was higher for BCC of mid-face/periauricular than other regions (P < 0.05). It can be concluded that micronodular BCC shows intermediate characteristics compared with nodular and infiltrative subtypes but appears to have a specific individuality making it a distinct subtype.

Merkel cell carcinoma and multiple basal cell carcinoma in an African albino woman with HIV infection

A 25-year-old HIV-infected African albino woman developed an aggressive Merkel cell carcinoma on her face and at least 10 basal cell carcinomas, mainly on sun-exposed parts of her body. HIV infection, immune deficiency and sun exposure are known risk factors for the development of Merkel cell carcinoma. Chemotherapy and radiotherapy were only temporarily successful. She died shortly after surgery was performed to remove the tumour.

Vulvar basal cell carcinoma: two unusual presentations and review of the literature

BACKGROUND

Basal cell carcinoma (BCC) of the vulva comprises 2-4% of all vulvar cancers. In general, vulvar BCCs tend to grow at slow rates. Nonetheless, they may be locally invasive and destructive if they are neglected. Eight cases of vulvar BCC metastatic to regional lymph nodes have been documented in the literature.

CASES

Two unusual cases of vulvar BCC are presented. Case 1 is an 86-year-old white woman who presented with vulvar BCC metastatic to the femoral head. This is the first report of hematogeneous metastasis of vulvar BCC. The patient was treated with palliative vulvar resection and radiation to the femoral metastasis. At 6 months, she progressed with multiple bony and intraperitoneal metastases and died with disease. Case 2 is vulvar BCC in a 90-year-old African-American woman. She was managed by wide local excision and remains disease free to date.

CONCLUSION

Vulvar BCCs are rare tumors with an unclear etiology. They can be aggressive and are capable of causing significant morbidity and occasional mortality if they are neglected or improperly treated. Hematogeneous metastasis at presentation appears to result in rapidly progressive disease. The literature regarding the pathogenesis, biologic behavior, and treatment of vulvar BCC is reviewed.

Cellular proliferation characteristics do not account for the behaviour of horrifying basal cell carcinoma. A comparison of the growth fraction of horrifying and non horrifying tumours

This study compared the clinical features, histological subtype, growth fraction (by Ki67 immunohistochemistry) and proliferation pattern of 22 clinically defined horrifying basal cell carcinoma compared to 81 non horrifying lesions. Late presentation was associated with half of the horrifying tumours. The other half developed horrifying tumours despite early intervention. The horrifying tumours exhibited a variety of histological growth patterns. A total of 50% were infiltrative, 23% nodular and 18% micronodular. There was no difference in the growth fraction or proliferation pattern between horrifying and non horrifying tumours of similar growth pattern (P = ns), although infiltrative tumours in either group exhibited a significantly higher growth fraction than nodular tumours (P < 0.01). This suggests that there is no intrinsic biological difference between horrifying and non horrifying tumours to account for their behaviour. We conclude that late presentation, failed or inadequate early management especially of infiltrative tumours (and other subtypes) determines the development of horrifying tumours.