Unknown primary Merkel cell carcinoma: 23 new cases and a review.

BACKGROUND: Knowledge is limited regarding unknown primary Merkel cell carcinoma (UPMCC). OBJECTIVE: We sought to document the characteristics and behavior of UPMCC, and determine the most appropriate treatment. METHODS: A multicenter, retrospective, consecutive study reviewing patients given a diagnosis of UPMCC between 1981 and 2008 was completed. In addition, a literature review of cases of UPMCC was performed. RESULTS: In all, 23 patients with UPMCC are described and 34 cases from previous reports are compiled. Among the 23 new cases of UPMCC, the average age at diagnosis was 66.0 years; the majority of patients were male (87%) and Caucasian (100% of those reported). One patient was immunosuppressed, and 39% had a history of other cancer. After the initial biopsy, 16 patients had further evaluation of the involved lymph node basin. Half of these had additional positive nodes (8 of 16). The majority of patients had lymph node basin involvement only (78%), whereas 22% had lymph node basin and distant metastasis. The most common lymph node basin involved was inguinal. The median size of the involved lymph node at diagnosis was 5.0 cm. At 2 years, the overall survival of stage IIIB UPMCC was significantly improved versus stage IIIB known primary Merkel cell carcinoma (MCC): 76.9% to 36.4%. LIMITATIONS: Limited number of cases and retrospective review are limitations. CONCLUSION: Our data demonstrate improved overall survival in patients with stage IIIB UPMCC versus those with stage IIIB known primary MCC. Because of the unpredictable natural history of UPMCC, we recommend individualization of care based on the details of each patient's clinical presentation.

Prognostic factors in Merkel cell carcinoma: analysis of 240 cases.

BACKGROUND: Knowledge regarding behavior of and prognostic factors for Merkel cell carcinoma (MCC) is limited. OBJECTIVE: We sought to further understand the characteristics, behavior, prognostic factors, and optimal treatment of MCC. METHODS: A multicenter, retrospective, consecutive study of patients with known primary MCC was completed. Overall survival and survival free of locoregional recurrence were calculated and statistical analysis of characteristics and outcomes was performed. RESULTS: Among the 240 patients, the mean age at diagnosis was 70.1 years, 168 (70.0%) were male, and the majority was Caucasian. The most common location was head and neck (111, 46.3%). Immunosuppressed patients had significantly worse survival, with an overall 3-year survival of 43.4% compared with 68.1% in immunocompetent patients. In our study, patients with stage II disease had improved overall survival versus those with stage I disease, in a statistically significant manner. Patients with stage III disease had significantly worse survival compared with stage I and with stage II. Primary tumor size did not predict nodal involvement. CONCLUSION: The data presented represent one of the largest series of primary MCC in the literature and confirm that MCC of all sizes has metastatic potential, supporting sentinel lymph node biopsy for all primary MCC. Because of the unpredictable natural history of MCC, we recommend individualization of care based on the details of each patient's tumor and clinical presentation.

The impact of biopsy technique on upstaging, residual disease, and outcome in cutaneous melanoma.

BACKGROUND: After skin biopsy of malignant melanoma, the findings in the subsequent wide local excision (WLE) sometimes result in upgrading of the T-category. Herein, we examine the influence of biopsy technique on residual disease in melanoma WLE specimens and on upstaging. METHODS: We performed a retrospective review of data from malignant melanoma patients who underwent sentinel lymph node biopsy between 1997 and 2010. RESULTS: A total of 609 patients were biopsied by shave (51%), punch (19%), and excision (30%). Residual disease was seen in 240 patients (39%) at WLE, of whom 60% had undergone shave biopsy. Fifty-nine patients had a T-category upgrade after WLE (10% of all patients); 64% were sampled by shave. Seven percent of patients with a T-category upgrade had negative margins initially. Positive biopsy margin and greater thickness predicted T-category upgrade. CONCLUSIONS: Partial biopsy for melanoma resulted in more residual disease at WLE and a higher rate of T-category upgrade. Moreover, the presence of negative margins at biopsy did not ensure lack of residual disease.

Correlation of thickness of basal cell carcinoma by optical coherence tomography in vivo and routine histologic findings: a pilot study.

BACKGROUND: Optical coherence tomography uses advanced photonics and fiber optics to obtain high-resolution cross-sectional images and tissue characterization in real time. OBJECTIVE: The objective was to correlate measurements of the depth of basal cell carcinomas obtained by optical coherence tomography and standard histopathologic examinations. METHODS: Twenty previously scanned optical coherence tomography images of histopathologically confirmed basal cell carcinoma were reviewed. A computer-generated depth scale was used to measure the depth of the neoplasm. These measurements were compared with direct measurements of tumor thickness of analogous tissue specimens made with a microscope micrometer. RESULTS: All 20 sites demonstrated excellent correlation of tissue thickness, to a depth of about 1 mm, estimated by optical coherence tomography or routine histopathologic tests. This depth correlation was consistent across several different types of basal cell carcinoma observed. CONCLUSION: Optical coherence tomography, compared with routine histopathologic techniques, shows promise as a method for estimating the superficial thickness of basal cell carcinoma.

Optical coherence tomography for the characterization of basal cell carcinoma in vivo: a pilot study.

BACKGROUND: Optical coherence tomography combines principles of ultrasonography and optical interferometry to provide real-time cross-sectional images of subsurface microstructure of tissue in vivo. OBJECTIVE: The purpose of this pilot study was to define and characterize basal cell carcinoma by using optical coherence tomography. METHODS: Twenty-three patients with 49 lesions clinically suggestive of superficial basal cell carcinoma were recruited. Optical coherence tomography was used to characterize the features of the pearly papules in real time and in vivo. Shave biopsy and light microscopic images were compared with images from optical coherence tomography. RESULTS: Basal cell carcinoma was identified in 27 patients; all 27 had optical coherence tomographic images for comparison. Seven images were uninterpretable, probably because of technical problems. Of the remainder, 20 sites matched the histologic features seen on light microscopy, with excellent correlation between optical coherence tomographic images and histopathologic features of superficial, nodular, micronodular and infiltrative basal cell carcinomas. LIMITATIONS: This study was limited by the small number of patients examined. Also, as this study was not designed as an intent-to-diagnose study, the actual predictive value of optical coherence tomography technology remains unproven. CONCLUSIONS: Optical coherence tomography technology has potential for the diagnosis and histopathologic characterization of basal cell cancer. Additional studies to determine any practical role for optical coherence tomography are indicated.

The exanthem of acute pulmonary coccidioidomycosis: Clinical and histopathologic features of 3 cases and review of the literature.

BACKGROUND: Coccidioidomycosis may be associated with a reactive generalized cutaneous eruption early in the course of the illness. Detailed descriptions in the literature are scarce. OBSERVATIONS: We describe 3 patients with a florid eruption associated with pulmonary coccidioidomycosis. The exanthem mimicked erythema multiforme clinically but not histologically. In 2 of the patients, the eruption began before the presence of detectable antibodies in the serum. CONCLUSION: The presence of the exanthem, in combination with fever and/or pneumonia, was a helpful clue to the diagnosis of coccidioidomycosis.

Gloves and socks syndrome: early and late histopathologic features.

BACKGROUND: Gloves and socks syndrome (GSS) is a recently described exanthem, most commonly caused by parvovirus B19. OBJECTIVE: Our purpose was to describe both early and late histopathologic features of GSS. METHODS: We performed histopathologic examination of biopsy specimens from a case of GSS and reviewed all the English-language literature reports of GSS to compare the reported histologic descriptions. RESULTS: A total of 46 cases of GSS have been reported in the English-language literature. In 18 of those, the pathologic features were described. The histologic features of the current case evolved from a nonspecific superficial perivascular lymphocytic infiltrate to a vacuolar interface dermatitis with necrotic keratinocytes, erythrocyte extravasation, and a superficial perivascular and interstitial lymphocytic infiltrate. CONCLUSION: Early lesions of GSS show nonspecific features common to viral exanthems. The late features, of a fully evolved exanthem, demonstrate a vacuolar interface dermatitis with necrotic keratinocytes, a superficial perivascular and interstitial infiltrate, and dermal hemorrhage. These late pathologic features, together with the clinical appearance of GSS, may help distinguish it from other entities.

Necrotizing cellulitis caused by Apophysomyces elegans at a patch test site.

Plant material occasionally is used in patch testing to diagnose contact dermatitis. Serious adverse reactions to this practice are extremely uncommon. The authors report on a 68-year-old non-insulin-dependent diabetic gentleman with hand dermatitis in whom severe necrotizing cellulitis developed caused by Apophysomyces elegans, a subtype of mucormycosis, at the site of a patch test to a snapdragon plant from his garden.