Modelling Keloids Dynamics: A Brief Review and New Mathematical Perspectives

Keloids are fibroproliferative disorders described by excessive growth of fibrotic tissue, which also invades adjacent areas (beyond the original wound borders). Since these disorders are specific to humans (no other animal species naturally develop keloid-like tissue), experimental in vivo/in vitro research has not led to significant advances in this field. One possible approach could be to combine in vitro human models with calibrated in silico mathematical approaches (i.e., models and simulations) to generate new testable biological hypotheses related to biological mechanisms and improved treatments. Because these combined approaches do not really exist for keloid disorders, in this brief review we start by summarising the biology of these disorders, then present various types of mathematical and computational approaches used for related disorders (i.e., wound healing and solid tumours), followed by a discussion of the very few mathematical and computational models published so far to study various inflammatory and mechanical aspects of keloids. We conclude this review by discussing some open problems and mathematical opportunities offered in the context of keloid disorders by such combined in vitro/in silico approaches, and the need for multi-disciplinary research to enable clinical progress.

Pagetoid Spread in Basal Cell Carcinoma: Potential for Misdiagnosis

ABSTRACT

Basal cell carcinomas are one of the most common cutaneous carcinomas and show classical histologic features of basaloid nests with peripheral palisading. Pagetoid and intraepidermal spread has not been described in basal cell carcinoma to the best of our knowledge. We report 5 cases of basal cell carcinoma with classic histologic patterns and overlying basaloid nests and single intraepidermal tumor cells. A panel of immunostains were performed that included CK7, MOC31, CEA-m, EMA, androgen receptor, and Bcl2. Most of our cases were positive for both MOC31 and CK7, and all cases were negative for CEA-m and EMA excluding extramammary Paget disease, one of the most common differential diagnoses. These cases expand the spectrum of findings that can be seen in basal cell carcinoma and can help prevent misdiagnoses of basal cell carcinomas as more aggressive tumors.

Keloidal Atypical Fibroxanthoma: Case and Review of the Literature

Keloidal atypical fibroxanthoma (KAF) has recently been categorized as a variant of atypical fibroxanthoma. This paper will emphasize the importance of including KAF in both clinical and histological differential diagnosis of benign and malignant lesions which exhibit keloidal collagen and will also review the current literature on epidemiology, pathogenesis, histology, immunochemistry and treatments.

Differential and exclusive diagnosis of diseases that resemble keloids and hypertrophic scars

Previous articles suggested the presence of various kinds of malignant tumors that resemble keloid or hypertrophic scar, including dermatofibrosarcoma protuberans, trichilemmal carcinoma, and keloidal basal cell carcinoma. Thus, we studied our cases that were diagnosed with diseases other than keloid or hypertrophic scar. From April 2003 to March 2007, we examined 378 patients self diagnosed with keloid or hypertrophic scar.We detected 4 other diseases (1.06%) in the group of patients. All tumors were benign: apocrine cystadenoma, adult-onset juvenile xanthogranuloma, mixed tumor, and chronic folliculitis. Our study led us to the conclusion that differential or exclusive diagnosis of diseases similar to keloid and hypertrophic scar is important. We found the following considerations important in the examination of keloid or hypertrophic scar: (1) biopsy should be conducted in anomalous cases because malignant disease may be the original or secondary problem, (2) steroid injection should be performed only after careful consideration because malignancy or infections may be present, (3) careful differential diagnosis is particularly challenging in African-Americans because skin and tumor color are often similar, and (4) the presence of bacterial or fungal infection should be investigated.

Merkel cell carcinoma frequently shows histologic features of basal cell carcinoma: a study of 30 cases

BACKGROUND

Merkel cell carcinoma (MCC) is a basaloid cutaneous neoplasm that may be mistaken for basal cell carcinoma (BCC).

METHODS

Thirty MCCs were examined for areas that histologically resembled BCC.

RESULTS

One of the histologic features of BCC (either a mucinous stroma or stromal artifactual retraction) was identified in all MCCs. A mucinous stroma was found in 28 MCCs (93%), stromal artifactual retraction in 27 (90%), mucin-containing gland-like spaces within tumor nests in 8 (27%), focal peripheral palisading in 8 (27%), epidermal involvement in 3 (10%) and dystrophic calcification in 1 MCC (3%). The cytologic features and absence of widespread peripheral palisading were the most reliable discriminators between MCC and BCC on routine sections. Squamous cell carcinoma was identified in four cases (13%). Two cases (7%) contained pagetoid intraepidermal spread (IES) of MCC. In one case, there was IES over the entire epidermal surface associated with intranuclear clearing, resembling the intranuclear cytoplasmic inclusions (INI) common in melanocytic tumors. INI were identified in six MCCs (20%).

CONCLUSIONS

MCCs frequently contain areas that histologically resemble BCC and other more common cutaneous malignancies. This can lead to diagnostic errors, particularly in small fragmented curettage specimens or frozen sections.

Keloidal Basal Cell Carcinoma

Herein is reported a third case of keloidal basal cell carcinoma.