Warty–basaloid carcinoma: clinicopathological features of a distinctive penile neoplasm. Report of 45 cases

Abstract

Most penile cancers are squamous cell carcinomas, but there are several subtypes with different clinicopathologic, viral, and outcome features. We are presenting 45 cases of a distinctive morphological variant of penile squamous cell carcinoma composed of mixed features of warty and basaloid carcinomas. This tumor was earlier recognized in a recent viral study and showed a high association with human papillomavirus infection. However, clinicopathologic features are not well known. In this multi-institutional study, patients' mean age was 62 years. Most tumors (64%) invaded multiple anatomical compartments, including glans, coronal sulcus, and, especially, inner foreskin mucosa. Tumor size ranged from 2 to 12 cm (mean 5.5 cm). Three morphological patterns were recognized: (1) the most common, observed in two-thirds of the cases was that of a typical condylomatous tumor on surface and basaloid features in deep infiltrative nests; (2) in 15% of the cases, there were non-papillomatous invasive carcinoma nests with mixed basaloid and warty features; and (3) unusually, predominantly papillomatous. Invasion of penile erectile tissues was frequent, either corpus spongiosum or cavernosum (47% each). Tumors limited to lamina propria were rare. Most tumors were of high grade (89%). Vascular and perineural invasion were found in about one-half and one-quarter of cases, respectively. Associated penile intraepithelial neoplasia was identified in 19 cases and mostly showed basaloid, warty-basaloid, or warty features. Inguinal nodal metastases were found in 11/21 patients with groin dissections. Invasion of corpora cavernosa, high histological grade, and presence of vascular/perineural invasion were more prevalent in metastatic cases. In 21 patients followed, the cancer-specific mortality rate was 33% with a mean survival time of 2.8 years. Warty-basaloid carcinomas are morphologically distinctive human papillomavirus-related penile neoplasms that, such as basaloid carcinomas, are biologically more aggressive than typical warty carcinoma from which they should be distinguished.

Advances in the pathology of penile carcinomas

“…One genotype was identified in most cases (48 cases; 75%) [38]. Like in other studies [23], HPV-16 was the most commonly detected genotype (72%), followed by HPV-6 (9%) and HPV-18 (6%), either in single or in multiple infections. No association of any of the genotypes with subtypes of SCC was found, although in usual SCC, a greater variety of single genotypes (16, 6, 45, 11, and 18) were detected as compared with other SCC subtypes.…”

“…In wartybasaloid carcinomas, most cells were small, uniform, and basophilic with scant nuclei, but they had a warty component with hyperkeratosis and parakeratosis, papillomatosis, and pleomorphic koilocytosis [23]. In basaloid carcinomas, the hallmark was the presence of tumor nests composed of small basophilic cells with central comedonecrosis [19].…”

“…4C and D). Metastatic rates are higher than in warty carcinoma but lower than in basaloid carcinoma [23].…”

Human Papilloma Virus: Prevalence, distribution and predictive value to lymphatic metastasis in penile carcinoma

“…Several pathological and molecular risk factor are being described in order to improve lymph node evaluation (24,25). Among pathological predictive factors, only PNI, LVI and histological grade are independent factors to predict lymph node involvement (25).…”

The variable morphological spectrum of penile basaloid carcinomas: differential diagnosis, prognostic factors and outcome report in 27 cases classified as classic and mixed variants

“…Basaloid features were characterized by a confluent or non confluent nesting pattern composed of basophilic cells with uniform small to intermediate size nuclei, frequent central necrosis or abrupt keratinization and numerous mitosis [21]. Tumors composed by at least 80% of cells with basaloid squamous cell carcinoma features [21] were classified as classic basaloid carcinoma, those with mixed features of warty or usual squamous cell carcinoma with at least 20% of basaloid carcinoma were defined as wartybasaloid [22] and usual-basaloid carcinoma respectively. Papillary neoplasms composed of small blue cells were typified as papillary basaloid carcinomas [15].…”