Pure and Mixed Variants of Desmoplastic Melanoma: A Single-Center, Retrospective, Clinicopathologic Review.

BACKGROUND: Desmoplastic melanoma (DM) is a rare melanoma variant. Prognostic indicators and survival vary widely and are further confounded by the histopathologic distinction between pure DM (pDM) and mixed DM (mDM) subtypes. The utility of current treatment guidelines is limited by the lack of evidence-based recommendations. OBJECTIVE: To compare the clinicopathologic characteristics of pure and mixed subtypes of DMs. METHODS: All cases of DM were identified from the Washington University in St Louis institutional pathology database between January 2000 and September 2022. Fifty-two cases were identified and subsequently categorized as pure ( n = 26) or mixed ( n = 26). Clinical and histopathologic data were collected and compared. RESULTS: There were no differences in demographics or tumor location between pure and mixed subtypes. Patients with mDM were more likely to have mitoses present ( p = .03). There were no differences in Breslow depth, tumor diameter, level of invasion, ulceration, and lymphovascular or perineural invasion. The utilization of sentinel lymph node biopsy ( p = .17) and sentinel lymph node positivity ( p = .67) were also similar. CONCLUSION: Despite histopathologic distinction between pDM and mDM, these subtypes were found to have similar clinicopathologic characteristics, including similar rates of sentinel lymph node metastasis.

CD30+ lymphoproliferative disorder masquerading as an atypical melanocytic proliferation.

Heuristics are cognitive strategies used to facilitate decision-making. They can be helpful tools for expediting pathologic diagnoses, however, they can also affect judgment and lead to biases that guide the pathologist astray. We report the case of a 52-year-old female who presented with two unusual pigmented lesions on the wrist and thigh that clinically and histopathologically resembled an atypical melanocytic proliferation. A biopsy of the thigh revealed a broad proliferation of large, atypical cells forming nests within a heavily pigmented epidermis. The lesion was initially misdiagnosed as melanoma in situ, despite equivocal staining for melanocytic markers, likely due to anchoring and adjustment as well as availability biases, which restricted the differential diagnosis and limited the selection of immunohistochemical stains. It was later discovered through chart review that the patient had a prior history of a cutaneous CD30+ lymphoproliferative disorder, which eventually led to the appropriate diagnosis in this case. Herein, we highlight a rare and unusual presentation of a pigmented epidermotropic CD30+ lymphoproliferative disorder, along with the biases leading to its misdiagnosis and the steps leading to the revelation of the actual diagnosis.

Primary Cutaneous Mucinous Carcinoma: A Review of the Literature.

BACKGROUND: Primary cutaneous mucinous carcinoma (PCMC) is an exceedingly rare, low-grade tumor that histologically resembles mucinous carcinoma from other primary sites, such as the breast, gastrointestinal tract, and lungs. OBJECTIVE: The purpose of this article was to review the current literature on PCMC as it relates to epidemiology, clinical presentation, histopathology, immunohistochemistry, treatment, and prognosis. MATERIALS AND METHODS: An extensive literature review was conducted using PubMed and Ovid MEDLINE to identify articles related to PCMC. RESULTS: Several hundred cases have been reported in the medical literature, and surgical resection, whenever feasible, is the standard of care. CONCLUSION: The diagnosis of primary cutaneous mucinous carcinoma is one of exclusion, requiring a metastatic work-up to rule out distant primary. Mohs micrographic surgery is a tissue sparing technique that allows complete margin control of these rare neoplasia.

Histopathologic and immunophenotypic features of cutaneous solid organ transplant-associated graft-vs-host disease: Comparison with acute hematopoietic cell transplant-associated graft-vs-host disease and cutaneous drug eruption.

BACKGROUND: Although it is relatively common after hematopoietic cell transplant (HCT), graft-vs-host disease (GVHD) is a rare complication following solid organ transplantation (SOT). METHODS: This study evaluated skin biopsy specimens from five cases of SOT GVHD, 15 cases of HCT GVHD, and 15 cases of cutaneous drug eruption. Immunohistochemical staining for CD3, CD4, CD8, T-bet, and GATA-3 was performed to examine the density and immune phenotype of skin-infiltrating lymphocytes. RESULTS: Similar to HCT GVHD, the predominant histopathologic findings in skin biopsy specimens of SOT GVHD were widespread vacuolar interface dermatitis with scattered necrotic keratinocytes. However, the density of dermal inflammation was considerably higher in SOT GVHD. Features that were more predictive of a cutaneous drug eruption over GVHD included spongiosis, confluent parakeratosis, and many eosinophils. Involvement of the hair follicle epithelium was seen in all three disorders. Both forms of cutaneous GVHD showed a predominance of Th1 (CD3+/T-bet+) lymphocytes within the inflammatory infiltrates. This shift was more pronounced in SOT GVHD, particularly among intraepidermal T-cells. CONCLUSIONS: SOT GVHD shares many histopathologic features with HCT GVHD. However, SOT GVHD has a greater tendency to develop brisk lichenoid inflammation.

Squamous Cell Carcinoma of the Hand: A Retrospective Study in Immunosuppressed and Immunocompetent Individuals.

BACKGROUND: Cutaneous squamous cell carcinoma (SCC) of the hand presents a treatment challenge because of the anatomical complexity of this location. Immunosuppressed patients are disproportionately affected by cutaneous SCC. Existing data on SCC of the hand are primarily presented in the orthopedic literature, and may thus be affected by referral bias. OBJECTIVE: Characterization of epidemiology and treatment outcomes for hand versus nonhand cutaneous SCC in immunosuppressed versus immunocompetent patients, across all clinical departments. MATERIALS AND METHODS: Single-institution retrospective cohort study of cutaneous SCC evaluated over 3 years and hand SCC over an additional 5 years. RESULTS: A cohort of 522 hand SCC cases (1,746 total SCC) was ascertained among 1,064 patients, of whom 175 were immunosuppressed. Occurrence on the hand was more common for SCC arising in immunosuppressed versus immunocompetent patients (38% vs 24% of cases respectively). Hand SCC cases demonstrated balanced laterality and comparable spectra of differentiation regardless of immunosuppression. No cases of hand SCC metastasis were observed over greater than 2 years' mean follow-up, and digital amputation was only required in approximately 1% of hand SCCs. CONCLUSION: In our cohort, assessment of hand SCC across all clinical departments suggests more favorable prognosis than reflected in the previous literature.

The Use of an Inferior Pennant Flap during Unilateral Cleft Lip Repair Improves Lip Height Symmetry.

BACKGROUND: To improve the rotation of Cupid's bow and achieve sufficient vertical lip height, several variations of the Millard rotation-advancement have incorporated a small laterally based triangular flap above the cutaneous roll. This study uses three-dimensional photogrammetry to evaluate the outcomes of unilateral cleft lip repairs performed with and without pennant flaps. METHODS: Three-dimensional photographs were analyzed to assess postoperative lip height asymmetry in 90 unilateral cleft lip patients (58 complete and 32 incomplete) treated between 2001 and 2012. Cleft lip repairs were performed by three pediatric cleft surgeons using different techniques. Thirty-nine of 90 procedures (43 percent) used an inferiorly placed triangular flap. All patients were photographed at least 9 months postoperatively (mean, 4.2 years). Lip height asymmetry was based on the vertical distances from the subnasale to the peaks of Cupid's bow. RESULTS: Regression analysis revealed that the use of a pennant flap was a significant predictor of postoperative lip height asymmetry (ß = 4.2 percent, p = 0.015). The surgeon performing the repair was also a significant factor in patients with complete cleft lips (ß = 3.6 percent, p = 0.005). All three surgeons achieved greater lip height symmetry when a pennant flap was performed. CONCLUSIONS: The results of unilateral cleft lip repairs are affected by both the surgeon and the surgical technique. Procedures that used a pennant flap showed better philtral height symmetry than nonpennant repairs. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

The path of the superior sagittal sinus in unicoronal synostosis.

PURPOSE: This study investigates the anatomic relationship between the superior sagittal sinus (SSS) and the sagittal suture in infants with uncorrected unicoronal synostosis. The morphology of the SSS is also evaluated postoperatively to assess whether normalization of intracranial structures occurs following reconstruction. METHODS: The study sample consisted of 20 computed tomography scans (10 preoperative, 6 postoperative, and 4 unaffected controls) obtained between 2001 and 2013. The SSS and the sagittal suture were outlined using Analyze imaging software. These data were used to measure the maximum lateral discrepancy between the SSS and the sagittal suture preoperatively and to assess for postoperative changes in the morphology of the SSS. RESULTS: In children with uncorrected unicoronal synostosis, the SSS deviates to the side of the patent coronal suture posteriorly and tends to follow the path of the sagittal and metopic sutures. The lateral discrepancy between the SSS and the sagittal suture ranged from 5.0 to 11.8 mm, with a 99.9 % upper prediction bound of 14.4 mm. Postoperatively, the curvature of the SSS was statistically decreased following surgical intervention, though it remained significantly greater than in unaffected controls. CONCLUSIONS: The SSS follows a predictable course relative to surface landmarks in children with unicoronal synostosis. When creating burr holes for craniotomies, the SSS can be avoided in 99.9 % of cases by remaining at least 14.4 mm from the lateral edge of the sagittal suture. Postoperative changes in the path of the SSS provide indirect evidence for normalization of regional brain morphology following fronto-orbital advancement.