Spontaneous resolution of a giant keratoacanthoma penetrating through the nose

A clinical and biological review of keratoacanthoma

Keratoacanthoma (KA) is a common skin tumour that remains controversial regarding classification, epidemiology, diagnosis, prognosis and management. Classically, a KA manifests as a rapidly growing, well-differentiated, squamoid lesion with a predilection for sun-exposed sites in elderly people and a tendency to spontaneously regress. Historically, KAs have been considered a variant of cutaneous squamous cell carcinoma (cSCC) and are often reported as KA-type cSCC. However, the penchant for regression has led many to categorize KAs as biologically benign tumours with distinct pathophysiological mechanisms from malignant cSCC. The clinical and histopathological similarities between KA and cSCC, particularly the well-differentiated variant of cSCC, have made definitive differentiation difficult or impossible in many cases. The ambiguity between entities has led to the general recommendation for surgical excision of KAs to ensure a potentially malignant cSCC is not left untreated. This current standard creates unnecessary surgical morbidity and financial strain for patients, especially the at-risk elderly population. There have been no reports of death from a definitive KA to date, while cSCC has an approximate mortality rate of 1·5%. Reliably distinguishing cSCC from KA would shift management strategies for KAs towards less-invasive treatment modalities, prevent unnecessary surgical morbidity, and likely reduce associated healthcare costs. Herein, we review the pathophysiology and clinical characteristics of KA, and conclude on the balance of current evidence that KA is a benign lesion and distinct from cSCC.

Self-involution of a solitary keratoacanthoma: A case report with photographic documentation

Keratoacanthoma (KA) is a common and distinctive cutaneous neoplasm that behaves in a benign fashion, displaying rapid growth followed by spontaneous involution. Clinical and histological examinations are essential to confirm this diagnosis, although differentiating KA from squamous cell carcinoma is often difficult. In general, complete surgical excision is a standard of care for solitary KAs; however, the conservative approach could be considered in some selected situations.

We present the case of a 59-year-old female patient who presented with a KA, on a high-risk area, displaying self-involution after undergoing a biopsy. This is one of the few cases in the literature in which spontaneous resolution process was photographically documented with good cosmetic results.

Keratoacanthoma of the Nasal Septum Secondary to Ranibizumab Use

Keratoacanthoma (KA) is a benign epithelial tumor that typically presents as a firm, cone-shaped, flesh-colored nodule with a central horn-filled crater. KA is considered to be a low-grade variant of squamous cell carcinoma (SCC). We report a rare case of a 72-year-old male who presented with a KA involving the nasal septum, possibly related to ranibizumab use. A flesh-colored lesion on the right anterior nasal septum lesion was visualized on examination. Histologic examination revealed a well-circumscribed, dome-shaped central crater filled with keratin, well-differentiated squamous epithelium with ground-glass cytoplasm with pushing margins, and intraepithelial microabscesses establishing the diagnosis of KA. KA of the nasal septum has only been reported once in the literature. This case is unusual because it normally presents on sun-exposed areas. Additionally, this patient was taking ranibizumab, a vascular endothelial growth factor (VEGF) inhibitor for macular degeneration. Despite ranibizumab not being directly linked to precancerous and cancerous skin lesions, agents in this medication class have been. Although it is difficult to prove associations in this isolated case, the role of ranibizumab causing cutaneous lesions should be further investigated.

Giant keratoacanthoma: case report and review of the English literature

The giant keratoacanthoma (KA) is a rare variant of KA with a maximum size exceeding 2-3 cm. Like other forms of KA, it has a tendency to spontaneously regress but can cause significant anatomic damage. A 69-year-old male presented to our hospital with a giant KA of the nose that showed complete pathological regression by the time of surgery. Pathology showed dermal scar with keratin granulomas extending through the nasal wall to the respiratory mucosa. A total of 57 similar cases from the English literature were reviewed for comparison. Few provide similar details of histological regression. Literature cases occurred predominately in males (74.1%) with a mean age of 59 years. Head tumors were most common (70.7%) and most were treated by surgery (34.5%) or a combination of surgery and radiotherapy (24.1%). Other treatment modalities reported include methotrexate, 5-fluorouracil, and interferon.

Spontaneous involution of keratoacanthoma, iconographic documentation and similarity with volcanoes of nature

Through iconography, we show a case of keratoacanthoma (KA) on the nasal dorsum at two different stages of evolution (maturation and regression) and its similarity with images of the Mount St. Helens volcano and the Orcus Patera crater. Using these illustrations, we highlight why the crateriform aspect of this tumor is included in its classic clinical description. Moreover, we photographically documented the self-involuting tendency of KA, an aspect that is seldom documented in the literature.