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

The Role of Smoothened-Dependent and -Independent Hedgehog Signaling Pathway in Tumorigenesis

The Hedgehog (Hh)-glioma-associated oncogene homolog (GLI) signaling pathway is highly conserved among mammals, with crucial roles in regulating embryonic development as well as in cancer initiation and progression. The GLI transcription factors (GLI1, GLI2, and GLI3) are effectors of the Hh pathway and are regulated via Smoothened (SMO)-dependent and SMO-independent mechanisms. The SMO-dependent route involves the common Hh-PTCH-SMO axis, and mutations or transcriptional and epigenetic dysregulation at these levels lead to the constitutive activation of GLI transcription factors. Conversely, the SMO-independent route involves the SMO bypass regulation of GLI transcription factors by external signaling pathways and their interacting proteins or by epigenetic and transcriptional regulation of GLI transcription factors expression. Both routes of GLI activation, when dysregulated, have been heavily implicated in tumorigenesis of many known cancers, making them important targets for cancer treatment. Hence, this review describes the various SMO-dependent and SMO-independent routes of GLI regulation in the tumorigenesis of multiple cancers in order to provide a holistic view of the paradigms of hedgehog signaling networks involving GLI regulation. An in-depth understanding of the complex interplay between GLI and various signaling elements could help inspire new therapeutic breakthroughs for the treatment of Hh-GLI-dependent cancers in the future. Lastly, we have presented an up-to-date summary of the latest findings concerning the use of Hh inhibitors in clinical developmental studies and discussed the challenges, perspectives, and possible directions regarding the use of SMO/GLI inhibitors in clinical settings.

Giant anterior chest wall basal cell carcinoma: a reconstructive challenge and review of the literature

Giant basal cell carcinomas (GBCC) are rare, accounting for <1% of BCCs. Those occurring on the anterior chest wall are a very rare subset that brings particular reconstructive challenges. We describe a 75-year-old man whose 13.5 cm diameter ulcerating GBCC on his left anterior chest came to medical attention following a fall. The lesion was resected en-bloc with adjacent ribs, and reconstructed with an omental flap, superiorly pedicled vertical rectus abdominus myocutaneous (VRAM) flap and split skin grafting. While the myriad reasons for delayed presentation of giant cutaneous malignancies are well documented, the complex nature of reconstruction and requirement for an integrated multidisciplinary approach are less so. It is of importance to note that the cicatricial nature of these lesions may result in a much larger defect requiring reconstruction than appreciated prior to resection. Documented cases of anterior chest wall GBCC and the treatment strategies employed are reviewed.

[Advanced skin tumors (incurables?) of the cephalic extremity: surgical considerations]

Suggest a surgical thinking for a multidisciplinary problem is inevitably difficult. Nevertheless, through targeted clinical examples, we tried to prioritize our clinical and intellectual approach for advanced tumors of the cephalic extremity. In these cases, decisions can only be collegial, and respect for the patient and his choices remain essential. Ultimately, we would argue this problematic, discussing successively the histological type, ethical concern with regard to clinic, operability and reconstruction opportunities.

Big Bad BCCs: craniofacial resection and reconstruction for atypical basal cell carcinomata

Basal cell carcinoma (BCC) is the most common malignancy of the body and most frequently occurs in the head and neck. 'Problematic aggressive' BCCs are either frequently recurrent, often after histologically confirmed clearance, or are 'giant/horrifying' and invasive of critical anatomy. Three patients that illustrate different clinical features and outcomes of 'problematic aggressive' craniofacial BCCs are reported that required craniofacial resection and reconstruction with microsurgical free flap cover, and a re-evaluation of our care pathway for these uncommon presentations.

The reverse auricular flap for the reconstruction of extended defects of the lower eyelid

The authors present eight cases of lower eyelid reconstruction after extended excision of cutaneous carcinomata. To recreate the supporting function of the lower eyelid it is necessary to reconstruct a rigid structure, which must replace the tarsus and has to be covered by sufficiently thin skin. A condrocutaneous helix island flap, based on the frontal branch of the temporal artery, allows us to reconstruct both lamellae of the eyelid at the same time. The reverse flow to the flap through this vascular pedicle is assured by the anastomotic branches from the supratrochlear and supraorbital arteries. Using this flap we have been able to recreate morphology and function of the lower eyelid with a good cosmetic result in the donor site as well.

Evaluation of basement membrane status in aggressive skin carcinomas with skull base invasion: a case-control study

Some skin carcinomas may be very aggressive. Breached of basement membrane (BM) has been in some situations associated with tumor aggressiveness. In this study, the status of BM in invasion was evaluated in basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs) with skull base invasion, and it was compared with tumor's good outcome. Integrity or breached of BM was visualized using immunohistochemistry technique with anti-type IV collagen antibody. The pattern of BM was classified as intact, breached, or absent in 24 BCCs and 11 SCCs with skull base invasion. Control group (good outcome) included 23 BCCs and 10 SCCs. Breached BM and absence of BM were respectively noted in 33.33% and 45.83% of BCCs with skull base invasion, compared with 8.33% and 17.395% in the control group ( P < .001). Regarding SCCs, ruptured and absent BMs were, respectively, noted in 36.36% and 63.64% of BCCs with skull base invasion, compared with 30% and 30% in the control group ( P = .075). In this study, destruction of BM was significantly more common in BCCs with skull base invasion, in comparison with those with good outcome. In SCC, this difference was not statistically significant.

Angiogenesis and skin carcinomas with skull base invasion: a case-control study

BACKGROUND

Some skin carcinomas may be very aggressive. Intensity of angiogenesis, measured by intratumoral vessel density using expression of CD34, has been associated with tumor aggressiveness. In this study, the expression of CD34 in basal cell carcinomas ( BCCs) and squamous cell carcinomas (SCCs) with skull base invasion was compared with that in tumors with good outcome.

METHODS

Expression of CD34 was graded as mild, moderate, and intense, in 24 BCCs and 11 SCCs with skull base invasion. The control group included 23 BCCs and 10 SCCs.

RESULTS

Intense expression of CD34 was noted in 25.00% of BCCs with skull base invasion, compared with 4.35% in the control group (p =.058). Regarding SCCs, intense expression of CD34 was found in 54.55% of aggressive tumors, compared with 10.00% in the control group (p =.133).

CONCLUSIONS

A trend toward denser microvascular angiogenesis was observed in both BCCs and SCCs with skull base invasion compared with less aggressive controls.

Expression of purinergic receptors in non-melanoma skin cancers and their functional roles in A431 cells

We investigated the use of purinergic receptors as a new treatment modality for nonmelanoma skin cancers. Purinergic receptors, which bind adenosine 5'-tri-phosphate, are expressed on human cutaneous keratinocytes. Previous work in rat and human epidermis suggested functional roles for purinergic receptors in the regulation of proliferation, differentiation, and apoptosis. Immunohistochemical analysis of frozen sections in human basal cell carcinomas and squamous cell carcinomas for P2X5, P2X7, P2Y1, P2Y2, and P2Y4 receptors was performed, accompanied by detailed analysis of archive material of tumor subtypes in paraffin sections. Functional studies were performed using a human cutaneous squamous cell carcinoma cell line (A431), where purinergic receptor subtype agonists were applied to cells and changes in cell number were quantified via a colorimetric assay. Immunostaining in paraffin sections was essentially the same as that in frozen sections, although more detail of the subcellular composition was visible. P2X5 and P2Y2 receptors were heavily expressed in basal cell carcinomas and squamous cell carcinomas. P2X7 receptors were expressed in the necrotic center of nodular basal cell carcinomas and in apoptotic cells in superficial multifocal and infiltrative basal cell carcinomas, and squamous cell carcinomas. P2Y1 receptors were only expressed in the stroma surrounding tumors. P2Y4 receptors were found in basal cell carcinomas but not in squamous cell carcinomas. P2X5 receptors appear to be associated with differentiation. The P2X7 receptor agonist benzoylbenzoyl-adenosine 5'-triphosphate and high concentrations of adenosine 5'-triphosphate (1000-5000 microM) caused a significant reduction in A431 cell number (p<0.001), whereas the P2Y2 receptor agonist uridine 5'-triphosphate caused a significant amount of proliferation (p<0.001). We have demonstrated that non-melanoma skin cancers express functional purinergic receptors and that P2X7 receptor agonists significantly reduce cell numbers in vitro.

Giant basal cell carcinoma affecting the lower abdominal, genital and bilateral inguinal regions

We describe a giant basal cell carcinoma, measuring 40 cm x 20 cm, of the lower abdominal, genital and bilateral inguinal regions. The rectus abdominis muscle and the adductor magnus muscle were exposed centrally, and the penis and scrotum were completely destroyed. Reconstruction was performed with a fillet thigh flap, and an excellent result was obtained 1 year after surgery.

Reporting basal cell carcinoma: a survey of the attitudes of histopathologists

AIMS

To investigate the histopathological reporting of basal cell carcinoma.

METHODS

Methods of classification and attitudes to excision margins were ascertained from histopathologists in 130 centres; 82 replies were obtained (63% response rate).

RESULTS

24% of those replying did not use any classification system for basal cell carcinoma. The remainder (76%) used a wide variety of different classification systems. A small number (9%) of those questioned felt reporting on completeness of excision was not important. The majority of histopathologists considered the excision margin was worth reporting but there were differences in methods of processing and reporting biopsies.

CONCLUSIONS

There is considerable variation in histopathological reporting of basal cell carcinoma. There is a need for uniformity of histopathological reporting to allow both improved management decisions and comparative audit of this extremely common skin cancer.