Multiple epithelioid Spitz nevi or tumors with loss of BAP1 expression: a clue to a hereditary tumor syndrome

IMPORTANCE

Recently, a group of melanocytic tumors with loss of BAP1 expression has been described. The lesions may occur sporadically or as part of a familial cancer syndrome. They have distinct histopathologic features characterized by a nevus like silhouette and cytologic composition of large epithelioid melanocytes with oval vesicular nuclei, distinct nucleoli, and abundant cytoplasm. The large melanocytes are immunohistochemically characterized by loss of nuclear labeling for BAP1.

OBSERVATIONS

We describe a 21-year-old patient with multiple combined melanocytic proliferations composed of both a nevus component with strong BAP1 expression and a large epithelioid melanocyte population with loss of BAP1 expression. The occurrence of multiple BAP1 loss melanocytic lesions raised concerns about a possible germline mutation. Sequence analysis of DNA from lesional and nonlesional skin confirmed a BAP1 germline mutation.

CONCLUSIONS AND RELEVANCE

The presence of multiple clinically banal-appearing melanocytic lesions with childhood onset suggests that the combined lesions with BAP1 loss large epithelioid melanocytes described herein are probably combined nevi. Our findings also illustrate how the detection of a histopathologically distinct melanocytic lesion, coupled with knowledge of its possible association with a hereditary tumor syndrome, can lead to the suspicion and confirmation of a germline mutation.

Peripheral and tumor immune correlates in patients with advanced melanoma treated with combination nivolumab (anti-PD-1, BMS-936558, ONO-4538) and ipilimumab

3003^

Background: Nivolumab and ipilimumab are fully human monoclonal antibodies that block the immune checkpoint receptors PD-1 and CTLA-4, respectively. In a multi-cohort, phase I study of nivolumab/ipilimumab combination therapy in melanoma patients (pts), objective response rates up to 47% were observed (NCT01024231). Putative predictive biomarkers from peripheral blood (PB) or tumor, including tumor PD-L1 expression, absolute lymphocyte count (ALC) and PB myeloid derived suppressor cells (MDSC) were evaluated. Pharmacodynamic changes in activated and effector T cells were also assessed. Methods: Tumor PD-L1 membrane expression was assessed in archival FFPE specimens by immunohistochemistry (28-8 PD-L1 antibody). ALC was measured in serial PB samples; changes in the percentage, number and phenotype of activated CD4+ and CD8+T cells and MDSC were characterized by flow cytometry. Results: PD-L1 expression was seen in 37% (10/27) of pts, using a cut-off of 5% tumor cell membrane staining. Objective responses (OR) were seen in pts with both PD-L1 negative (8/17) and PD-L1 positive (4/10) tumors. Relative to baseline, a rise in ALC was not detected, but phenotypic changes in PB T-cell subsets, including increases in the percentage of CD4 and CD8 expressing HLA-DR, ICOS and/or Ki67 were seen with combination therapy. Low ALC (<1.0 at wk 6-7) did not preclude OR as 3 of 12 pts with low ALC responded. Of pts evaluated, OR with ≥80% reduction in tumor burden at 12 wk were seen in pts with a low frequency of pretreatment PB MDSC (3/7) but no OR were seen in pts with high MDSC (0/6). Conclusions: In this small subset of pts,OR were seen independent of PD-L1 or ALC status in contrast to prior observations with nivolumab or ipilimumab, respectively. Thus, the immune response generated by combination therapy may have unique features compared to either monotherapy. The relationship between frequency of PB MDSC and reduction in tumor burden will be further explored. Further efforts in this study and in future phase III randomized studies will investigate these and other phenotypic changes in immune cell populations and their relationship to patterns of clinical activity. Clinical trial information: NCT01024231.

Desmoplastic melanoma: a review

Desmoplastic melanoma (DM) is a variant of spindle cell melanoma typically found on chronically sun-damaged skin of older individuals. Early diagnosis can be challenging because it is often amelanotic and has a predominantly dermal component. DM can be difficult to diagnose not only clinically but also histologically, and can be mistaken for a variety of benign and malignant nonmelanocytic spindle cell tumors when viewed on prepared histopathology slides. Pathologists have observed that DMs can manifest significant variation with respect to the extent of intratumoral cellularity, fibrosis, and/or perineural invasion. Furthermore, some tumors present with a pure desmoplastic invasive component (>90%) while other tumors display mixed features of DM and nondesmoplastic melanoma. This has led to the separation of DM into 2 histologic subtypes, pure and mixed. With a focus on the distinction between pure and mixed DM, this review will detail what is currently known about the diagnostic features of DM, discuss risk and prognostic factors, and examine the current literature on disease progression and management.

Rash with the multitargeted kinase inhibitors nilotinib and dasatinib: meta-analysis and clinical characterization

OBJECTIVES

Nilotinib and dasatinib are second-generation tyrosine kinase inhibitors approved for the treatment of chronic myeloid leukemia (CML). In clinical trials, they have both been reported to cause rash in a significant number of patients, but its incidence varies significantly and has not been characterized clinically or histologically. The aim of this study was to determine the incidence of rash with nilotinib and dasatinib, and to provide a clinical and histopathological description of the rash.

METHODS

We conducted a meta-analysis of clinical trials evaluating nilotinib and dasatinib to determine and compare the incidence of rash with these medications. Additionally, we performed a retrospective chart review to analyze the clinical presentation and histology of patients presenting with rash.

RESULTS

The incidence of all-grade (grade 1-4) rash with nilotinib was 34.3% (95% CI, 27.9-41.3), higher (P = 0.017) than with dasatinib (23.3%; 95% CI, 18.8-28.6). Similarly, the incidence of high-grade rash with nilotinib (2.6%; 95% CI, 2.1-3.4) was higher (P = 0.002) than with dasatinib (1.1%; 95% CI, 0.8-1.6). The clinical presentation often consisted of a pruritic, perifollicular hyperkeratotic, occasionally erythematous papular rash affecting most areas of the body, depending on the severity.

CONCLUSIONS

Both nilotinib and dasatinib are associated with rash in a significant number of patients. Further studies to prevent and treat rash with nilotinib and dasatinib are required to improve patient quality of life, adherence with therapy and oncologic outcome.

Clinical value of paraffin sections in association with Mohs micrographic surgery for nonmelanoma skin cancers

BACKGROUND

During Mohs micrographic surgery (MMS), situations can arise in which paraffin sections may be used in conjunction with frozen sections.

OBJECTIVE

To determine the clinical value of paraffin sections in association with MMS, including frequency, reasons, and information obtained.

METHODS AND MATERIALS

Single-center retrospective cohort study at a cancer center. MMS cases for nonmelanoma skin cancers over a 5-year period in which paraffin sections were used were identified. Reasons for submitting paraffin sections were reviewed. Initial biopsy, Mohs frozen section, and paraffin section diagnoses and histologic subtypes were compared.

RESULTS

In 258 (7.8%) cases, paraffin sections were used in association with MMS. The most common reasons were to further assess high-risk histologic features or unusual frozen section findings, to complete tumor staging of cutaneous squamous cell carcinomas, and to assess perineural invasion (PNI). Initial biopsy diagnosis differed from the Mohs frozen and paraffin section diagnoses in 20% to 22% of cases. The initial biopsy histologic subtype changed from low or indeterminate to high risk in Mohs frozen and paraffin sections in 24% to 29% of cases.

CONCLUSION

In MMS for select high-risk or unusual nonmelanoma skin cancers, paraffin sections are useful in more accurately documenting tumor histology, completing cutaneous squamous cell carcinoma staging, and detecting PNI.

Desmoplastic melanocytic nevi with lymphocytic aggregates

Desmoplastic melanocytic nevi can be difficult to distinguish from desmoplastic melanoma. The presence of lymphocytic aggregates in association with a sclerosing melanocytic proliferation is commonly regarded as a feature in support of a diagnosis of desmoplastic melanoma. However, the finding is not specific for melanoma. Herein we report six cases of sclerosing melanocytic nevi with associated lymphocytic aggregates. They occurred in five women and one man, ranging in age from 11 to 61 years. Three lesions were sclerosing Spitz nevi; one was an amelanotic sclerosing blue nevus, one an acquired intradermal sclerosing nevus, and one was a congenital compound melanocytic nevus with sclerosis of its dermal component. The lesions were interpreted as benign, i.e. melanocytic nevi, because of their histopathologic attributes (symmetric silhouette, benign cytologic features) and results from immunohistochemical studies (all lesions strongly expressed Melan-A and p16) and fluorescence in situ hybridization (FISH). Three lesions tested by FISH lacked copy number changes of 11p, 6q or 6p. None of the lesions recurred. The cases highlight that contextual information is essential for the diagnosis of desmoplastic melanoma and sclerosing nevus. The presence of lymphocytic aggregates per se does not prove that a sclerosing melanocytic proliferation is malignant.

Clinical experience with atypical spitzoid tumors in patients younger than age 18: Does fluorescence in situ hybridization predict lymph node metastasis?

8586

Background: Determining the malignant potential of atypical spitzoid melanocytic proliferations can be diagnostically challenging, and many patients are therefore managed as if they had melanoma. However, few studies focus specifically on atypical spitzoid tumors (AST). Further, cytogenetic analysis using fluorescence in situ hybridization (FISH) has been used to determine malignant potential. We reviewed our institutional experience to determine staging and clinical outcomes, and the correlation between FISH findings and regional nodal positivity in patients with AST. Methods: With IRB approval, we retrospectively reviewed all patients aged <18 years treated for AST from 1981-2011 to determine staging variables, outcome, and the results of 4-probe FISH assay. A total of 44 patients with a median age of 11.5 years were identified. All pathology was re-reviewed by a single dermatopathologist. Staging was based on 2010 AJCC criteria. Correlations were determined using either the Pearson or Spearman correlation coefficient. Results: Median lesion thickness was 2.8 mm (range: 0.55-12) and eight (18%) lesions met spitzoid melanoma criteria. Median followup was 4.1 years for all patients (5.5 years for spitzoid melanomas). Thirty-nine patients (89%) underwent sentinel lymph node biopsies (SLNB) and 15 (38%) were positive. Lymph node (LN) positivity correlated with tumor thickness (p=0.002), stage (p=0.001), and mitotic rate (p=0.05). FISH was available for 17/39 patients who had SLNB; sensitivity and specificity for LN metastases were 50% and 54%, respectively. Of 15 patients with a positive SLNB, 12 underwent completion LN dissection, three of which were positive for 1, 2, and 3 additional nodes, respectively. There were no recurrences or disease-related deaths. Conclusions: Traditional indicators of thickness and stage predicted nodal involvement in pediatric patients with AST. However, FISH results did not predict nodal status and should not be used to guide management. With 100% disease specific survival and no recurrences, AST should be considered a separate entity from melanoma and complete excision may be sufficient therapy.

Fluorescence In Situ Hybridization (FISH) Analysis of Melanocytic Nevi and Melanomas

A 4-color fluorescence in situ hybridization (FISH) assay, using probes to chromosomes 11q, 6p, 6q, and 6 cent, has recently been proposed as an ancillary tool for the diagnosis of melanoma. The authors report herein their experience with this assay. To determine the sensitivity and specificity of the assay for histopathologically unequivocal cases, they analyzed 50 melanocytic nevi, 50 primary melanomas, and 15 metastatic melanomas. Of 50 melanocytic nevi, 47 were FISH negative on initial readout (test sensitivity, 94%); 49 were FISH negative after correction for tetraploidy (test specificity, 98%). Of 50 primary melanomas, 41 were FISH positive (test sensitivity, 82%). Of 15 metastatic lesions, 13 were FISH positive (test sensitivity, 85%). Of the 9 FISH-negative melanomas, 6 metastasized. The tumors of the 5 patients who had survived thick primary melanoma for more than 5 years without recurrence were all FISH positive. Half of the patients whose primary melanoma was tested by FISH had undergone sentinel lymph node (SLN) biopsy. When the authors compared the FISH results of those 25 melanomas with the SLN status, no statistically significant correlation was found. These findings document limitations of the current FISH assay. A rare nevus may be FISH positive. Some primary metastasizing melanomas are FISH negative. Even metastatic melanomas can be FISH negative. Awareness of the limitations in test sensitivity and specificity of the FISH assay is important to avoid an erroneous diagnosis by overreliance on cytogenetic findings. Correlation with clinical and histopathological findings is paramount for accurate diagnosis.

Association between melanocytic neoplasms and seborrheic keratosis: more than a coincidental collision?

Clinical observations and an expanding knowledge of cell-to-cell communication have led us to speculate that the finding of a melanocytic nevus in conjunction with a seborrheic keratosis is more than a coincidental collision of two lesions. Here we present five cases demonstrating dermoscopic features of both melanocytic lesions and seborrheic keratoses with corresponding histology. Four cases demonstrate dermoscopic features of a melanocytic nevus and seborrheic keratosis, and the final case a melanoma arising in association with a seborrheic keratosis.

Clinical and histopathologic characteristics of rash in cancer patients treated with mammalian target of rapamycin inhibitors

BACKGROUND

Dermatologic adverse events stemming from anticancer therapies have become an increasingly frequent clinical problem. Inhibitors of mammalian target of rapamycin (mTOR), such as temsirolimus and everolimus, have been associated with a high rate of skin eruptions, but their clinical and histopathologic characteristics have not been explored.

METHODS

A retrospective analysis of patients who were referred to the Dermatology Service for diagnosis and management of rash in the setting of therapy with the mTOR inhibitors everolimus and temsirolimus was performed. The parameters that were studied included the time to onset, clinical presentation at the time of dermatologic evaluation, associated symptoms, evolution, results of microbiologic studies, concomitant medications, the need for dose reduction and/or treatment interruption because of rash, and routine histopathology.

RESULTS

In total, 13 patients were analyzed. Most rashes were mild (grade 1; 31%) and moderate (grade 2; 54%) in severity, and grade 3 rashes were observed only in 2 patients (15%). The trunk was the most frequently affected region (77%), with the scalp (23%), face (38%), neck (54%), and extremities (69%) also commonly involved. Erythematous papules and pustules constituted the predominant primary lesion morphology (62%). No unique or uniform histopathologic reaction pattern was observed. The most common reaction pattern was that of a mixed, spongiotic interface and perivascular dermatitis, which was observed in 7 of 11 patients (63%).

CONCLUSIONS

Although mTOR inhibitors may commonly induce erythematous papules and pustules, they are associated with a spectrum of lesion morphologies and a variety of histopathologic findings. Further clinicohistologic correlation studies are needed.

Use of Fluorescence In Situ Hybridization to Distinguish Metastatic Uveal From Cutaneous Melanoma

Metastatic lesions of malignant melanoma can on occasion be difficult to classify with regard to the primary site of origin. Given the lack of specificity of light microscopic features, ancillary studies are needed. In this study, the authors explored the possibility of distinguishing metastatic tumors derived from uveal primaries from those known to have originated from a cutaneous melanoma by fluorescence in situ hybridization (FISH) using probes for chromosome 3, 8q24, and 1p36. A total of 32 metastatic tumors were analyzed by FISH. Monosomy 3 was detected in 9 out of 16 (56.3%) cases of metastatic uveal melanoma but was not found in any of the 16 metastatic cutaneous melanomas ( P < .001). With regard to 1p36, amplifications were found in 8 out of 16 (50%) cases of metastatic cutaneous melanoma but not in any case of uveal melanoma ( P < .05). 1p36 was deleted in 3 cases of uveal and 1 case of cutaneous melanoma. Amplifications of 8q were found in 15 out of 16 (94%) cases of uveal melanoma metastases and in 12 out of 16 (75%) cases of cutaneous metastases. The findings suggest that FISH for monosomy 3 is a useful adjunct tool in the differential diagnosis of metastatic uveal versus cutaneous melanoma.

Expert second-opinion pathology review of lymphoma in the era of the World Health Organization classification

BACKGROUND

The World Health Organization (WHO) classification of hematologic malignancies, published in 2000, was designed to improve diagnostic accuracy by incorporating the latest in scientific understanding. The impact of the WHO classification on the frequency of diagnostic discrepancy in lymphoma is unknown.

METHODS

We reviewed all second-opinion pathology of lymphoma at our National Cancer Institute-designated Comprehensive Cancer Center (NCI-CCC) from January to June 2001 and from January to June 2006. Discrepancies between submitted and second-opinion diagnoses were scored based upon an a priori grading schema.

RESULTS

Major diagnostic revision was rendered in 65 of 365 cases (17.8%) in 2001 and 58 of 354 (16.4%) in 2006 (P=NS). Including cases reviewed and revised beforehand at another NCI-CCC, rates of major diagnostic revision were 21.4% and 18.6%, respectively (P=NS). Discrepancy rates varied by diagnosis, from Hodgkin lymphoma (10%) to Burkitt's lymphoma (75%). No association was seen for age, gender, race/ethnicity, biopsy type, or nature of referring center.

CONCLUSIONS

Clinically meaningful diagnostic revision occurs frequently with expert pathology review for a diagnosis of lymphoma. Despite the WHO classification, rates of diagnostic revision at our institution in 2001 and 2006 did not differ significantly. Given the potential harm from misdiagnosis, expert hematopathology review should be considered the standard of care.

Selective radiotherapy for the treatment of head and neck Merkel cell carcinoma

BACKGROUND

The role of radiotherapy (RT) in the management of Merkel cell carcinoma (MCC) is controversial. The authors of this report evaluated the rates and patterns of failure in a selected group of patients who underwent RT for MCC of the head and neck (HN).

METHODS

The records of 145 consecutive patients with MCC of the HN who presented to the authors' institution between 1988 and 2009 were reviewed. Only patients who received RT at the institution were included. The cumulative incidence of locoregional failure (LRF), distant metastatic failure (DMF), disease progression (DP) and disease-specific death (DSD) were estimated with death as a competing risk.

RESULTS

Forty-eight patients were identified. The median follow-up was 51 months (range, 6-220 months) for living patients. LRF developed in 5 patients (10%), and those patients had a median time to recurrence of 3 months. Two of the 5 LRFs were local and developed at the edge of the treatment field; the remaining 3 LRFs were in lymph nodes and occurred outside the treatment field. DMF developed in 12 patients (25%). The estimated 5-year cumulative incidences of LRF, DP, and DSD were 10%, 30%, and 21%, respectively. Acute toxicities included 5 episodes (10%) of grade 3 dermatitis and 1 episode (2%) of grade 3 mucositis.

CONCLUSIONS

The authors report a site-specific series of patients with HN MCC who received RT. In this group of patients with adverse features, RT was well tolerated, and LRF was low. The propensity for MCC to recur at the edge of the treatment field suggests that generous margins are appropriate when RT is administered.

Prognostic significance of regulators of cell cycle and apoptosis, p16(INK4a), p53, and bcl-2 in primary mucosal melanomas of the head and neck

Abnormalities in cell cycle regulation, tumor suppressor gene functions and apoptosis are frequent events in tumorigenesis. Their role in the pathogenesis and prognosis of primary mucosal melanomas (MM) of the upper aerodigestive tract remains unknown. Sixty-four patients (40 men, 24 women, median age 64 years) with MM were included in this study; 32 had tumors in the nasal/paranasal cavities, 28 in the oral cavity and 4 in the pharynx. Archival tissues from 47 initial mucosal tumors, 17 mucosal recurrences, and 13 nodal/distant metastases were subjected to immunohistochemistry using antibodies against p16, p53, and bcl-2. The results were correlated with histological features and survival data. Expressions of p16, p53, and bcl-2 proteins were seen in 25% (N=19/76), 21% (N=16/76), and 74% (N=56/76) of all tumors, respectively. bcl-2 expression in the initial tumors was associated with significantly longer overall and disease specific survival (3.3 vs. 1.5 years, P ≤ 0.05). Expression of p16 was increasingly lost, from 32% in initial tumors to 12% in recurrent and 15% in metastatic tumors (P=0.06). Tumors comprised of undifferentiated cells were significantly more p53 positive than epithelioid or spindle cells (80% vs. 33%, P=0.02). Expression of these markers did not correlate with necrosis, or vascular and/or deep tissue invasion. Expression of bcl-2 is associated with better survival in MM. Loss of p16 was seen with tumor progression whereas aberrant p53 expression was frequent in undifferentiated tumor cells.

Recurrence after complete resection and selective use of adjuvant therapy for stage I through III Merkel cell carcinoma

BACKGROUND

Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine neoplasm whose natural history is poorly understood. Here, the authors describe their experience with a large cohort of patients who were treated at a single institution to describe patterns of recurrence after curative therapy.

METHODS

Review of a prospective database was performed. Patient-related, tumor-related, and treatment-related variables were recorded, and the site and timing of initial recurrence were recorded. Factors associated with receipt of adjuvant therapy and recurrence were determined.

RESULTS

In total, 364 patients with stage I through III MCC who underwent complete resection were identified. Adjuvant local radiation therapy (RT), lymph node RT, and chemotherapy were received selectively by 23%, 23%, and 15% of patients, respectively. Factors associated with the receipt of adjuvant therapy included younger age, primary tumor features (larger size, lymphovascular invasion [LVI], positive margin excision), and increasing pathologic stage. With median follow-up of 3.6 years, 108 patients (30%) developed a recurrence, including 11 local recurrences (3%), 12 in-transit recurrences (3%), 43 lymph node recurrences (12%), and 42 distant recurrences (12%). Clinically involved lymph nodes, primary tumor LVI, and a history of leukemia/lymphoma were predictive of recurrence. The majority of recurrences (80%) occurred in patients who had clinically involved lymph nodes or patients who did not undergo pathologic lymph node evaluation.

CONCLUSIONS

A low recurrence rate in patients with clinically lymph node-negative MCC was achieved with adequate surgery (including sentinel lymph node biopsy) and the selective use of adjuvant RT for high-risk tumors. In contrast, patients with clinically lymph node-positive MCC had significantly higher rates of recurrence, especially distant recurrence. The authors concluded that contemporary natural history studies are critical in designing treatment pathways and clinical trials for MCC.

Bexarotene is active against subcutaneous panniculitis-like T-cell lymphoma in adult and pediatric populations

INTRODUCTION

Subcutaneous panniculitis-like T-cell lymphoma (SPTL-AB) and cutaneous gamma/delta T-cell lymphoma (CGD-TCL) are rare T-cell lymphomas with varying clinical courses. There is no standard treatment, although chemotherapy and hematopoietic stem cell transplantation are commonly used. We describe results using bexarotene for children and adults with these disorders.

METHODS

We identified 15 patients (12 adults, 3 children) who were treated with bexarotene between 2000 and 2010 from the Memorial Sloan-Kettering Cancer Center lymphoma database, the Stanford Cancer Center Registry, and the National Cancer Institute (NCI) pediatric lymphoma database. There were 8 females and 7 males, with a median age of 45 years (range, 3 years to 85 years). All patients had stage IV disease. Two of 15 and 4 of 15 patients had documented CGD-TCL and SPTL-AB, respectively; others were presumed to have SPTL-AB. Bexarotene was administered at flat doses corresponding to 91 to 339 mg/m(2)/d. Two of 15 patients received concurrent denileukin diftitox. Two children received bexarotene as maintenance therapy and were not evaluable for response.

RESULTS

Among those treated with bexarotene alone, the overall response rate (ORR) was 82% (6/11 complete response [CR], 3/11 partial response [PR]). One of the 2 patients treated with concomitant denileukin diftitox responded for an ORR of 10/13 (77%), including 54% CR and 23% PR. Median progression-free survival was 38.4 months; median duration of response was 26.3 months. Six patients developed hypothyroidism and 9 developed hyperlipidemia; one patient developed dose-limiting hypertriglyceridemia. One pediatric patient developed insulin-dependent diabetes mellitus.

CONCLUSIONS

In this retrospective series, bexarotene showed a high response rate in SPTL-AB and CGD-TCL. It was generally well-tolerated with durable responses; therefore, bexarotene represents a promising therapy for children and adults with these disorders.