Medusa head-like granules in squamous cell carcinoma with differentiation toward a hair follicle structure

Two cases of infundibular squamous cell carcinoma on the nose with aggressive clinical behavior: Case report and review of the published work

Case 1 was a 75-year-old Japanese man who presented with a poorly demarcated, dark-red nodule with a destructive defect in the center, measuring 3 cm × 2 cm on the right wing of his nose. The histological diagnosis was a common form of infundibular squamous cell carcinoma. Atypical neoplastic cells radiated from the wall of a follicular infundibulum. The majority of neoplastic cells were positive for AE1/AE3 and 34βE12. Cytokeratin 17 expression was seen in the suprabasal cells of the deeply situated neoplastic components. Case 2 was a 73-year-old Japanese man who presented with a poorly demarcated, dark-red nodule with an irregularly shaped ulcer in the center, measuring 3 cm × 2 cm on the left wing of his nose. The histological diagnosis was a crater form of infundibular squamous cell carcinoma. Atypical neoplastic cells radiated from the broad base of the central keratin-filled crater, continuous with two infundibular canals. In both cases, some of the more deeply situated aggregations were composed of neoplastic keratinocytes with eosinophilic glassy or pale cytoplasm. In addition, no atypical keratinocytes could be seen in the interfollicular epidermis. In case 1, a hematogenous metastasis to the vocal cord and the forehead occurred in addition to a lymph node metastasis. In case 2, a local recurrence occurred with an intralymphatic dissemination. We describe two cases of infundibular squamous cell carcinoma on the nose with aggressive clinical behavior, one of which was accompanied by a hematogenous metastasis while another revealed a local recurrence.

Cutaneous squamous cell carcinoma: a comprehensive clinicopathologic classification

Cutaneous squamous cell carcinoma (SCC) includes many subtypes with widely varying clinical behaviors, ranging from indolent to aggressive tumors with significant metastatic potential. However, the tendency for pathologists and clinicians alike is to refer to all squamoid neoplasms as generic SCC. No definitive, comprehensive clinicopathological system dividing cutaneous SCCs into categories based upon their aggressiveness has yet been promulgated. Therefore, we have proposed the following based upon the malignant potential of SCC variants, separating them into categories of low (< or = 2% metastatic rate), intermediate (3-10%), high (greater than 10%), and indeterminate behavior. Low-risk SCCs include SCC arising in actinic keratosis, HPV-associated SCC, tricholemmal carcinoma, and spindle cell SCC (unassociated with radiation). Intermediate-risk SCCs include adenoid (acantholytic) SCC, intraepidermal epithelioma with invasion, and lymphoepithelioma-like carcinoma of the skin. High-risk subtypes include de novo SCC, SCC arising in association with predisposing factors (radiation, burn scars, and immunosuppression), invasive Bowen's disease, adenosquamous carcinoma, and malignant proliferating pilar tumors. The indeterminate category includes signet ring cell SCC, follicular SCC, papillary SCC, SCC arising in adnexal cysts, squamoid eccrine ductal carcinoma, and clear-cell SCC. Subclassification of SCC into these risk-based categories, along with enumeration of other factors including tumor size, differentiation, depth of invasion, and perineural invasion will provide prognostically relevant information and facilitate the most optimal treatment for patients.

Cutaneous squamous cell carcinoma: a comprehensive clinicopathologic classification. Part one

Cutaneous squamous cell carcinoma (SCC) includes many subtypes with widely varying clinical behaviors, ranging from indolent to aggressive tumors with significant metastatic potential. However, the tendency for pathologists and clinicians alike is to refer to all squamoid neoplasms as generic SCC. No definitive, comprehensive clinicopathological system dividing cutaneous SCCs into categories based upon their aggressiveness has yet been promulgated. Therefore, we have proposed the following based upon the malignant potential of SCC variants, separating them into categories of low (< or = 2% metastatic rate), intermediate (3-10%), high (greater than 10%), and indeterminate behavior. Low-risk SCCs include SCC arising in actinic keratosis, HPV-associated SCC, tricholemmal carcinoma, and spindle cell SCC (unassociated with radiation). Intermediate-risk SCCs include adenoid (acantholytic) SCC, intraepidermal epithelioma with invasion, and lymphoepithelioma-like carcinoma of the skin. High-risk subtypes include de novo SCC, SCC arising in association with predisposing factors (radiation, burn scars, and immunosuppression), invasive Bowen's disease, adenosquamous carcinoma, and malignant proliferating pilar tumors. The indeterminate category includes signet ring cell SCC, follicular SCC, papillary SCC, SCC arising in adnexal cysts, squamoid eccrine ductal carcinoma, and clear-cell SCC. Subclassification of SCC into these risk-based categories, along with enumeration of other factors including tumor size, differentiation, depth of invasion, and perineural invasion will provide prognostically relevant information and facilitate the most optimal treatment for patients.

Proliferating trichilemmal tumour: p53 immunoreactivity in association with p27Kip1 over-expression indicates a low-grade carcinoma profile

AIMS

Alterations of cell-cycle regulatory molecules in tumorigenesis may predict the biological behaviour of neoplasms and greatly contribute to their proper classification. Since the behaviour of proliferating trichilemmal tumour (PTT) is controversial, we decided to explore the possible significance of altered p53 and p27Kip1 immunohistochemical expression patterns in PTT.

METHODS AND RESULTS

We evaluated the percentage and distribution of positive tumour cells and compared the results with those obtained from usual trichilemmal cysts (TC) and squamous cell carcinomas with trichilemmal differentiation (SCCT). PTT showed p53 immunoreactivity (50.4 +/- 29.6, mean +/- standard deviation) that was not statistically different from that seen in SCCT (75.2 +/- 36.3). On the other hand, p53 immunostaining was virtually absent in TC cases (positivity for p53 was observed in only one instance in < 1% of cells). As for p27Kip1, the mean percentage of positive cells in PTT (82.7 +/- 9.9) was slightly lower than in TC (90.6 +/- 4.6) but significantly higher than in SCCT (53.4 +/- 30).

CONCLUSIONS

The similar p53 immunoreactivity in both PTT and SCCT favour the interpretation of the former as carcinoma, albeit one whose behaviour would be tempered by the well-known regulatory effect exerted by p27Kip1 on the cell cycle.

A unique case of squamous cell carcinoma showing adenocarcinomatous features with focal apocrine differentiation

We report an 85-year-old man with squamous cell carcinoma on the right pinna. Two years after the excision of the lesion, metastatic foci were found extending from the right retromandibular to the mastoid region and into the parapharyngeal space. Histopathologically, the primary tumor showed interconnecting nests of atypical cells invading into the dermis from multiple epidermal and infundibular foci. The tumor had both squamous and glandular differentiation. A peculiar finding was the presence of decapitation secretion in the glandular foci. To our knowledge, definite apocrine differentiation in squamous cell carcinoma has not previously been reported.