Squamous cell carcinoma of the scalp in organ transplant recipients: exploring mechanisms for recurrence and treatment guidelines.

BACKGROUND: The scalp is a target for squamous cell carcinoma (SCC) in male organ transplant recipients (OTRs) with alopecia. These tumors can behave aggressively and are associated with high recurrence, morbidity, and mortality. Treatment guidelines are needed for SCC in the scalp of OTRs. OBJECTIVE: To explore the clinical and histologic features associated with SCC recurrence and aggressiveness in the scalp of OTRs. We review the mechanisms involved as they relate to a case. An algorithm for evaluation and treatment is introduced. METHODS: An OTR presented with poorly differentiated SCC of the scalp that recurred on three occasions after Mohs micrographic surgery (MMS). The final recurrence invaded the bone and cranial cavity. We discuss the difficulties encountered in evaluating and treating these patients. RESULTS: This patient had multiple factors associated with high tumor recurrence and aggressiveness. These were explored, and an algorithm was created. CONCLUSION: SCC in the scalp of OTRs presents challenges for evaluation and management. We must be vigilant to monitor for recurrence, perineural invasion, bone invasion, multiple-field tumors, and metastasis. An understanding of the mechanisms of tumor recurrence will assist us in preventing morbidity and mortality in this subset of patients.

Cytokeratin 5/6 immunostaining in cutaneous adnexal neoplasms and metastatic adenocarcinoma.

The differentiation of primary cutaneous adnexal neoplasms (CANs) from dermal-based metastatic lesions can be difficult. Cytokeratin 5/6 (CK 5/6) has a relatively limited expression profile, being relatively specific for mesothelium and other "pavement" type epithelium such as squamous epithelium. To date, the degree and distribution of CK 5/6 expression in cutaneous neoplasms has not been extensively studied. We speculate that since most of CANs arise from similar epithelium, they should express CK 5/6 and, therefore, CK 5/6 could potentially be helpful in distinguishing these lesions from most of metastatic neoplasms, which usually do not express this marker. Formalin-fixed, paraffin-embedded tissue sections from 228 previously classified CANs and 27 metastatic adenocarcinomas (17 breast, 4 colon, 2 prostate, 2 ovary, 1 lung, and 1 esophagus) were immunostained with anti-CK 5/6. Anti-CK 5/6 labeled 2 of 2 proliferating trichilemmal tumors, 6 of 6 poromas, 4 of 5 hydrocystomas, 10 of 10 cylindromas, 10 of 10 eccrine acrospiromas, 8 of 10 pilomatricoma, 10 of 10 nevus sebaceus, 9 of 9 desmoplastic trichoepitheliomas, 7 of 7 nevus sebaceus with basal cell carcinomas, 10 of 10 pilar cysts, 14 of 14 trichilemmomas, 10 of 10 syringomas, 6 of 7 chondroid syringomas, 10 of 10 hidradenoma papilliferum, 9 of 9 sebaceus adenomas, 3 of 3 microcystic adnexal carcinomas, 10 of 10 eccrine spiradenomas, 4 of 4 syringocystadenoma papilliferum, 3 of 5 ocular sebaceous carcinomas, 28 of 28 basal cell carcinomas, 16 of 16 trichoepitheliomas, and 33 of 33 trichoepitheliomas with basal cell features. By contrast, 9 of 27 metastatic adenocarcinomas stained positively, although only two of these stained strongly. Cumulatively, CK 5/6 was expressed by most (97%) of CANs, while only 33% of metastatic adenocarcinomas showed positive expression. The sensitivity of this marker in the malignant lesions (other than basal cell carcinoma) is 78%, while the specificity is 67%. If all lesions are considered, the sensitivity increases to 97%. Therefore, CK 5/6 may prove to be a useful adjunct marker in distinguishing CANs from metastatic lesions.

Use of bipolar energy for transurethral resection of bladder tumors: pathologic considerations.

BACKGROUND AND PURPOSE: Bipolar electrocautery has recently been introduced as a modality for transurethral resection of bladder tumors (TURBT). The primary benefits of bipolar TURBT stem from the use of saline irrigant rather than glycine or water. TURBT should be conducted in a fashion such that the resected tissue can be used for proper grading and staging, so excessive cauterization of the tissue should be avoided. In this study, we compared the pathologic characteristics of bladder tumor specimens resected with bipolar versus standard monopolar energy to determine specimen quality. PATIENTS AND METHODS: Bipolar TURBT (Gyrus Medical Inc., Maple Grove, MN) was performed in 11 patients. Pathologic specimens were compared with the specimens from 11 patients who had previously undergone standard monopolar TURBT. Resected tissue was examined by a pathologist who recorded tumor size, grade, location, presence of muscularis propria, presence of muscle invasion, and final diagnosis. The pathologist also determined the degree of cautery artifact in each specimen. The pathologist was blinded to the form of electrocautery used and the clinical diagnosis. RESULTS: Transurethral resection with bipolar electrocautery was carried out without difficulty or complication in all cases. Similarly, there were no complications in resection by standard monopolar electrocautery. The bladder tumor chips obtained with bipolar TURBT were smaller because of the smaller size of the bipolar loop. However, this did not interfere with the pathologic assessment. There were no significant pathologic differences between specimens according to the type of cautery used. A large degree of cautery artifact was noted in the tissue of larger tumors resected using both monopolar and bipolar electrocautery. However, the incidence and degree of cautery artifact were similar in the two groups. No trends between tumor location and degree of cautery effect were noted. The pathologist had no difficulty reaching a full and proper diagnosis in all cases involving either form of electrocautery. CONCLUSIONS: Bipolar electrocautery is well suited for TURBT. Bladder tissue obtained from bipolar TURBT is of the same histologic quality as that obtained from standard monopolar TURBT and provides the urologist with a reliable and complete diagnosis.

Proliferating trichilemmal tumor with a malignant spindle cell component.

BACKGROUND: Proliferating trichilemmal tumors (PTTs) are uncommon exuberant growths of cells derived from the external root sheath. They tend to occur in older women, with a predilection for the scalp. Resection is usually curative. Spindle cell components arising within PTTs are exceedingly rare, with only three known cases previously reported. Of these three cases, one patient died from widespread metastasis. METHODS: Histological and immunohistochemical examinations were performed on a tumor from a 54-year-old man which, after exhibiting slow growth for 3 years, increased rapidly in size. RESULTS: Microscopic examination revealed cystic lobules of squamous cells without a granular cell layer surrounding amorphous eosinophilic debris within the dermis. Also present was a poorly circumscribed focus of spindle cells with hyperchromasia, pleomorphism, giant cells, and abundant mitoses, including abnormal forms. Immunohistochemistry showed the spindle cells to stain positively for vimentin, but negatively for keratin, epithelial membrane antigen and S-100 antibodies. CONCLUSION: A malignant spindle cell component arising within a PTT is a rare neoplasm which has been associated with death from widespread metastasis.