The effect of cannabinoids on single-level lumbar arthrodesis outcomes in a rat model.

BACKGROUND CONTEXT: The opioid epidemic is a public health crisis affecting spine care and pain management. Medical marijuana is a potential non-opioid analgesic yet to be studied in the surgical setting since its effects on bone healing are not fully understood. Studies have demonstrated analgesic and potentially osteoinductive properties of cannabinoids with endocannabinoid receptor expression in bone tissue. PURPOSE: We hypothesize that tetrahydrocannabinol (THC) and cannabidiol (CBD) will not decrease bone healing in spinal fusion. STUDY DESIGN: Seventy-eight adult Sprague-Dawley rats were used for this study. Utilizing allogenic bone grafts (6 donor rats), posterolateral inter-transverse lumbar fusion at the L4-L5 level was performed. The animals were equally divided into four treatment groups, each receiving 0.1 ml intraperitoneal injections weekly as follows: placebo (saline), 5 mg/kg THC, 5 mg/kg CBD, and a combination of 5 mg/kg THC and 5mg/kg CBD (Combo). METHODS: Callus tissue was harvested 2- and 8-weeks post-surgery for qPCR assessment to quantify changes in the expression of osteogenic genes. Manual palpation was done to assess the strength of the L4-L5 arthrodesis on all rats. µCT image-based callus analysis and histology were performed. One-way ANOVA followed by post hoc comparisons was performed. RESULTS: µCT demonstrated no significant differences. Treatment groups had slightly increased bone volume and density compared to control. qPCR at two weeks indicated downregulated RANKL/OPG ratios skewing towards osteogenesis in the CBD group, with the THC and CBD+THC groups demonstrating a downward trend (p>.05). ALPL, BMP4, and SOST were significantly higher in the CBD group, with CTNNB1 and RUNX2 also showing an upregulating trend. The CBD group showed elevation in Col1A1 and MMP13. Data at eight weeks showed ALPL, RUNX2, BMP4, and SOST were downregulated for all treatment groups. In the CBD+THC group, RANK, RANKL, and OPG were downregulated. OPG downregulation reached significance for the THC and CBD+THC group compared to saline. Interestingly, the RANKL/OPG ratio showed upregulation in the CBD and CBD+THC groups. RANKL showed upregulation in the CBD group. At 2 and 8 weeks, the CBD treatment group showed superior histological progression, increasing between time points. CONCLUSION: This study demonstrates that CBD and THC have no adverse effect on bone healing and the rate of spinal fusion in rats. Osteogenic factors were upregulated in the CBD-treated groups at two weeks, which indicates a potential for bone regeneration. In this group, compared to control, the RANKL/OPG ratio at the early healing phase demonstrates the inhibition of osteoclast differentiation, enhancing bone formation. Interestingly, it shows promoted osteoclast differentiation at the later healing phase, enhancing bone remodeling. This aligns with the physiological expectation of a lower ratio in the early phases and a higher ratio in the later remodeling phases. CLINICAL SIGNIFICANCE: CBD and THC showed no inhibitory effects on bone healing in a spinal fusion model. Moreover, histologic and gene expression analysis demonstrated that CBD may, in fact, enhance bone healing. Further research is needed to confirm the safe usage of THC and CBD in the post-operative setting following spinal fusions.

Unusual isolated cytomegalovirus cutaneous infections: A subtle histopathologic diagnosis with review of the literature.

Cytomegalovirus (CMV) infection is common and often self-limited. Reactivation results in a variety of disease presentations, especially in the setting of immunocompromise. While cutaneous manifestations of systemic CMV infection are rare, dermatologic manifestations of CMV are increasingly reported with a wide morphologic spectrum clinically. Three male patients, with untreated human immunodeficiency virus (HIV), penile lichenoid dermatitis treated with long-term topical and intralesional corticosteroids, and metastatic Merkel cell carcinoma on immune checkpoint inhibitor therapy, each presented with isolated cutaneous ulcers. The ulcers were located on the perianal skin, glans of the penis, and distal thumb. In each case, nonspecific histopathologic features were seen. However, very rare dermal cytomegalic cells with nuclear and cytoplasmic inclusions were present and highlighted with an immunohistochemical stain for CMV. Isolated ulcers due to CMV infection may occur in the setting of systemic or localized immunosuppression. A high index of suspicion is needed upon histopathologic evaluation, as few cytomegalic cells may be present and accurate diagnosis is crucial for prompt and appropriate clinical management.

Molecular Profiling of Syringocystadenocarcinoma Papilliferum Reveals RAS-Activating Mutations.

CONTEXT.­: Syringocystadenocarcinoma papilliferum (SCACP) is a rare adnexal carcinoma and the malignant counterpart of syringocystadenoma papilliferum (SCAP), which is commonly located on the head and neck and may arise in association with a nevus sebaceus. RAS mutations have been identified in both SCAP and nevus sebaceus. OBJECTIVE.­: To evaluate the clinicopathologic and molecular features of SCACPs, which have not been previously explored. DESIGN.­: We obtained 11 SCACPs from 6 institutions and reviewed the clinicopathologic features. We also performed molecular profiling using next-generation sequencing. RESULTS.­: The cohort comprised 6 women and 5 men with ages ranging from 29 to 96 years (mean, 73.6 years). The neoplasms occurred on the head and neck (n = 8; 73%) and extremities (n = 3; 27%). Three tumors possibly arose in a nevus sebaceus. A total of 4 cases showed at least carcinoma in situ (adenocarcinoma, n = 3; squamous cell carcinoma [SCC], n = 1), and 7 cases were invasive (SCC, n = 5; mixed adenocarcinoma + SCC, n = 2). A total of 8 of 11 cases (73%) had hot spot mutations consisting of HRAS (n = 4), KRAS (n = 1), BRAF (n = 1), TP53 (n = 4), ATM (n = 2), FLT3 (n = 1), CDKN2A (n = 1), and PTEN (n = 1). All 4 cases with HRAS mutations occurred on the head and neck, whereas the KRAS mutation occurred on the extremity. CONCLUSIONS.­: RAS-activating mutations were detected in 50% of the cases, of which most (80%) involved HRAS and occurred on the head and neck, which shows overlapping features with SCAP, supporting that a subset may arise as a result of malignant transformation and likely an early oncogenic event.

Atretic cephalocele and encephalocele: A single-institution clinicopathological study.

BACKGROUND: Encephaloceles are neural tube defects characterized by herniation of meninges, neural tissue and cerebrospinal fluid, while atretic cephaloceles denote a rudimentary connection to the intracranial space with absence of herniated neural tissue and represent an infrequent dermatopathologic diagnosis. Limited reports of these entities confound the challenge in their histopathologic distinction. Accurate classification is important given associated anomalies and neurologic manifestations that impact prognosis. METHODS: We describe the clinicopathological and immunohistochemical [glial fibrillary acidic protein (GFAP), S100, epithelial membrane antigen (EMA), and somatostatin receptor subtype 2A (SSTR2A)] features in a retrospective series encountered at a single institution between 1994 and 2020. RESULTS: We identified 13 cases classified as atretic cephalocele (n = 11) and encephalocele (n = 2). Hamartomatous changes and multinucleated cells were unique to atretic cephaloceles while myxoid areas were unique to encephaloceles. At least focal staining for SSTRA was seen in all atretic cephaloceles with the majority (87.5%) staining for EMA; negative staining for GFAP and S100 confirmed absence of neural tissue. Encephaloceles were GFAP and S100 positive, and negative for SSTR2 and EMA. Atretic cephaloceles had a favorable prognosis compared to encephaloceles, with severe morbidity present in both encephalocele cases. CONCLUSION: Our study raises awareness of atretic cephalocele and encephalocele among dermatopathologists and reveals a mutually exclusive immunophenotype that facilitates their distinction for prognostication and management.

Minimally invasive, sustained-release relaxin-2 microparticles reverse arthrofibrosis.

Substantial advances in biotherapeutics are distinctly lacking for musculoskeletal diseases. Musculoskeletal diseases are biomechanically complex and localized, highlighting the need for novel therapies capable of addressing these issues. All frontline treatment options for arthrofibrosis, a debilitating musculoskeletal disease, fail to treat the disease etiology-the accumulation of fibrotic tissue within the joint space. For millions of patients each year, the lack of modern and effective treatment options necessitates surgery in an attempt to regain joint range of motion (ROM) and escape prolonged pain. Human relaxin-2 (RLX), an endogenous peptide hormone with antifibrotic and antifibrogenic activity, is a promising biotherapeutic candidate for musculoskeletal fibrosis. However, RLX has previously faltered through multiple clinical programs because of pharmacokinetic barriers. Here, we describe the design and in vitro characterization of a tailored drug delivery system for the sustained release of RLX. Drug-loaded, polymeric microparticles released RLX over a multiweek time frame without altering peptide structure or bioactivity. In vivo, intraarticular administration of microparticles in rats resulted in prolonged, localized concentrations of RLX with reduced systemic drug exposure. Furthermore, a single injection of RLX-loaded microparticles restored joint ROM and architecture in an atraumatic rat model of arthrofibrosis with clinically derived end points. Finally, confirmation of RLX receptor expression, RXFP1, in multiple human tissues relevant to arthrofibrosis suggests the clinical translational potential of RLX when administered in a sustained and targeted manner.

Use of Cytokeratin 17 in the Differentiation Between Desmoplastic Trichilemmoma and Cutaneous Basal Cell Carcinoma.

ABSTRACT: Desmoplastic trichilemmoma (DTL) is a variant of trichilemmoma characterized by a prominent desmoplastic stroma that may mimic invasive carcinoma. These lesions typically show features of a conventional trichilemmoma at the periphery, surrounding dense hyalinized stroma with entrapped cords of tumor cells. On a small or superficial biopsy, DTL may pose a diagnostic challenge in distinguishing this benign adnexal neoplasm from invasive carcinoma, particularly basal cell carcinoma (BCC). We aimed to investigate whether the immunohistochemical expression of cytokeratin 17 (CK17) would be useful in the differentiation between DTL and BCC. CK17 is expressed in normal adnexal structures and has been shown to demonstrate strong staining in BCCs. Expression of CK17 was examined in 23 cases of DTL and 23 BCCs. An immunoreactivity score was assigned using the percentage of tumor cells staining with scoring as follows: 0, complete negativity; 1, < 15% tumor cells staining; 2, 15%-84% tumor cells staining; and 3, >85% staining. All cases of BCC scored as 3, whereas 18% of DTL scored as 3. The mean percent staining for CK17 was significantly higher for BCCs (97% of tumor cells) than DTLs (57% of tumor cells); P < 0.001 in the unpaired t test. The pattern of CK17 staining may also help differentiate between cases scoring 3. All BCCs showed strong diffuse staining throughout, whereas for those cases of DTL with a score of 3, the peripheral basaloid rim in the tumor lobules did not stain. CK17 is a useful adjunct in distinguishing DTL from BCC in small or superficial biopsy specimens.

The NALCN channel regulates metastasis and nonmalignant cell dissemination.

We identify the sodium leak channel non-selective protein (NALCN) as a key regulator of cancer metastasis and nonmalignant cell dissemination. Among 10,022 human cancers, NALCN loss-of-function mutations were enriched in gastric and colorectal cancers. Deletion of Nalcn from gastric, intestinal or pancreatic adenocarcinomas in mice did not alter tumor incidence, but markedly increased the number of circulating tumor cells (CTCs) and metastases. Treatment of these mice with gadolinium-a NALCN channel blocker-similarly increased CTCs and metastases. Deletion of Nalcn from mice that lacked oncogenic mutations and never developed cancer caused shedding of epithelial cells into the blood at levels equivalent to those seen in tumor-bearing animals. These cells trafficked to distant organs to form normal structures including lung epithelium, and kidney glomeruli and tubules. Thus, NALCN regulates cell shedding from solid tissues independent of cancer, divorcing this process from tumorigenesis and unmasking a potential new target for antimetastatic therapies.

From Churg-Strauss Syndrome to Eosinophilic Granulomatosis With Polyangiitis: A Historical Review of Nomenclature and Diagnostic Criteria.

ABSTRACT: Eosinophilic granulomatosis with polyangiitis (EGPA) is rare vasculitis syndrome that involves the skin and other organ systems manifesting as asthma, eosinophilia, and pulmonary infiltrates. The understanding of EGPA, previously known as Churg-Strauss Syndrome, has continued to evolve from its earliest documentation in the literature in 1951. Herein, we review key historical advances in the diagnosis, classification, and nomenclature of EGPA that have shaped our understanding of this protean disorder over time.

Clinical and pathologic correlation of cutaneous COVID-19 vaccine reactions including V-REPP: A registry-based study.

BACKGROUND: Cutaneous reactions after COVID-19 vaccination have been commonly reported; however, histopathologic features and clinical correlations have not been well characterized. METHODS: We evaluated for a history of skin biopsy all reports of reactions associated with COVID-19 vaccination identified in an international registry. When histopathology reports were available, we categorized them by reaction patterns. RESULTS: Of 803 vaccine reactions reported, 58 (7%) cases had biopsy reports available for review. The most common histopathologic reaction pattern was spongiotic dermatitis, which clinically ranged from robust papules with overlying crust, to pityriasis rosea-like eruptions, to pink papules with fine scale. We propose the acronym "V-REPP" (vaccine-related eruption of papules and plaques) for this spectrum. Other clinical patterns included bullous pemphigoid-like (n = 12), dermal hypersensitivity (n = 4), herpes zoster (n = 4), lichen planus-like (n = 4), pernio (n = 3), urticarial (n = 2), neutrophilic dermatosis (n = 2), leukocytoclastic vasculitis (n = 2), morbilliform (n = 2), delayed large local reactions (n = 2), erythromelalgia (n = 1), and other (n = 5). LIMITATIONS: Cases in which histopathology was available represented a minority of registry entries. Analysis of registry data cannot measure incidence. CONCLUSION: Clinical and histopathologic correlation allowed for categorization of cutaneous reactions to the COVID-19 vaccine. We propose defining a subset of vaccine-related eruption of papules and plaques, as well as 12 other patterns, following COVID-19 vaccination.

Sporadic superficial angiomyxomas demonstrate loss of PRKAR1A expression.

Superficial angiomyxomas are cutaneous mesenchymal tumours that typically present clinically as slow-growing, solitary, asymptomatic nodules that can occur at any age. Histopathologically, these dermal and subcutaneous tumours are characterized by abundant myxoid stroma, numerous thin-walled and often arbourising blood vessels, and spindled to stellate fibroblast-like cells. While usually sporadic, superficial angiomyxomas can occasionally be associated with Carney complex (CNC), an autosomal dominant disorder characterized by inactivating germline mutations in the 1-alpha regulatory subunit of protein kinase A (PRKAR1A) and various clinical manifestations, including cardiac myxomas, facial lentigines, epithelioid blue naevi, endocrinopathies and psammomatous melanotic schwannomas. In this study, we sought to characterize the presence or absence of PRKAR1A expression by immunohistochemistry (IHC) in sporadic superficial angiomyxomas based on our observations in an index case. In total, PRKAR1A immunohistochemical expression was determined in 15 sporadic superficial angiomyxoma cases retrieved from the surgical pathology archives. IHC demonstrated that the lesional cells in 12 cases (80%) were non-reactive to antibodies against PRKAR1A. This study provides evidence in support of a role for PRKAR1A in the development of clinically non-syndromic superficial angiomyxomas. Together with previous studies, this report demonstrates that PRKAR1A may play an important role in the development of a variety of myxomatous mesenchymal tumours.

Symmetric drug-related intertriginous and flexural exanthema: Clinicopathologic study of 19 cases and review of literature.

BACKGROUND: Symmetric drug-related intertriginous and flexural exanthema (SDRIFE) is a cutaneous drug reaction characterized by gluteal/anogenital erythema and symmetric involvement of other intertriginous location(s) without systemic signs. Clinicopathologic characterization has been limited to case reports and small series. We describe 19 new cases and review the literature to better define the clinical and histopathologic spectrum of SDRIFE. METHODS: Pathology archives were searched for "SDRIFE" and "baboon syndrome." Cases meeting clinical criteria were included. Clinical and histopathologic features were recorded. Previous reports of SDRIFE with histopathologic descriptions were reviewed. RESULTS: Nineteen new cases were included, over half triggered by antibiotics. Six new causative medications were identified. Median onset was 7 days. Typical lesions were erythematous plaques or papules with or without scale. The most common histopathologic finding was superficial perivascular lymphocytic infiltrate followed by dermal eosinophils, spongiosis, and orthokeratosis. Basal vacuolization and apoptotic keratinocytes were less common. Interstitial histiocytes were present in almost half of our cases. Other findings included atypical lymphocytes and "flame figure." CONCLUSIONS: Appreciation of the range of inciting medications and clinicopathologic features in SDRIFE will improve recognition of this condition. Although many histopathologic features overlap with other common dermatitides, biopsy may assist in excluding key clinical mimics.

Eosinophilic granulomatosis with polyangiitis: Cutaneous clinical and histopathologic differential diagnosis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare, but severe systemic vasculitis that can affect skin and other organ systems. Diagnostic criteria have evolved, and many attempts have been made to classify the vasculitides based on clinical and/or histopathologic features, with an aim to develop standardized criteria. According to the EGPA Consensus Task Force recommendations, EGPA is a syndrome of asthma, eosinophilia, pulmonary infiltrates, and extrapulmonary vasculitis (such as cutaneous involvement with purpura). Histopathologic evidence of vasculitis in EGPA may be associated with eosinophilic infiltration and/or perivascular granulomatous inflammation. We review clinicopathologic criteria of this enigmatic vasculopathy.

Distinction Between Hypertrophic Lichen Planus and Squamous Cell Carcinoma Requires Clinicopathologic Correlation in Difficult Cases.

ABSTRACT: Distinguishing hypertrophic lichen planus (HLP) and squamous cell carcinoma (SCC) can be diagnostically challenging because of overlapping clinical and histopathological features. This study characterizes histopathological features in HLP and SCC, assessing their utility in diagnosing atypical squamous proliferations. We compared 12 histopathological features of 15 HLP and 11 SCC biopsies from the lower extremities. We then reviewed 16 cases that were diagnosed as atypical squamous proliferations with differential diagnoses of HLP versus SCC. Clinical follow-up allowed for retrospective categorization of these difficult cases as HLP or SCC. HLP showed significant differences in hyperorthokeratosis (P = 0.04), wedge-shaped hypergranulosis (P = 0.0033), and irregular psoriasiform hyperplasia (P = 0.004), whereas parakeratosis (P = 0.001), solar elastosis (P = 0.001), deep extension (P = 0.02), and perforating elastic fibers (P = 0.0001) were significant for SCC. A scoring system based on these significant differences was devised to aid the classification of difficult cases. 56% of the difficult cases received an "indeterminate" score. A score favoring HLP had a sensitivity of 44% and a specificity of 71%. Although significant differences were identified between cases of definitive HLP and SCC, these histopathological features were unable to distinguish difficult cases, highlighting the need for clinicopathological correlation in patients with atypical squamous proliferations of the lower extremities. Many difficult cases had histologic features that could not be evaluated because of the superficial nature of the biopsy. Therefore, obtaining a deep wedge or punch biopsy may facilitate a diagnosis in cases with a differential diagnosis of HLP and SCC.

Peristomal Punctate Pemphigus.

ABSTRACT: Cutaneous reactions surrounding abdominal stoma sites are typically irritant, allergic, infectious, traumatic or pathergic in etiology. Pemphigus, which encompasses a group of vesiculobullous autoimmune skin disorders, is seldom encountered as a peristomal dermatosis. Direct immunofluorescence (DIF) studies of pemphigus generally show continuous intercellular net-like depositions of IgG. However, punctate or dot-like intercellular deposition of IgG can also be seen in cases of pemphigus. The punctuate pattern is underreported in the literature and little is known about its implication. We describe a case of a 58-year-old Caucasian man with a history of bowel obstruction, status postcolostomy, who presented with a sharply demarcated, erythematous, crusted plaque surrounding his abdominal stoma. The patient endorsed persistent pruritus. A punch biopsy of the lesion was performed for clinical suspicion of fungal infection versus irritant dermatitis. Histopathology revealed a predominantly subcorneal acantholytic dermatitis. Periodic acid-Schiff with diastase and Grocott methenamine silver histochemical stains were negative for fungi. DIF was positive for IgG and C3 detected in a punctate intercellular pattern. In conjunction with the patient's clinical presentation and DIF, a diagnosis of peristomal pemphigus foliaceous was rendered. Herein, we describe a case of punctate pemphigus presenting as a peristomal dermatosis and include a review of the literature to raise awareness of this phenomenon.

Assessing interobserver variability and accuracy in the histological diagnosis and classification of cutaneous neurofibromass.

BACKGROUND: Cutaneous neurofibromas (cNFs) are the most common tumors in people with neurofibromatosis type 1 (NF1) and are associated with reduced quality of life. There is currently no widely accepted standardized language for describing cNFs clinically or histopathologically. The objective of this study was to evaluate interobserver agreement across pathologists in describing and reporting of neurofibromas involving the skin. METHODS: Twenty-eight (H&E)-stained slides of cNF were scanned using an Aperio XT scanner. The digital images were reviewed by 6 pathologists, who entered free text of up to a 200 word description for each case into a REDcap database. Responses were analyzed for the most commonly used terms based on frequency, as well as agreement (reported as concordance) between reviewers. RESULTS: A set of the terms most commonly used by pathologists for the histological classification of cNF along with areas of agreement and disagreement have been identified. The study shows that there was strong agreement across reviewers that not all neurofibromas involving the skin are cutaneous neurofibromas and regarding the presence or absence of atypical features and heterologous elements. Areas of less concordance were identified and include cNF subtypes, definition of extension and pattern of growth, as well as the distinction of a cNF from a plexiform without an intraneural component involving skin. CONCLUSIONS: This work is the first step towards development of a robust classification system and devising "gold standard" histopathologic diagnostic criteria for cutaneous neurofibromas.

Subacute cutaneous lupus erythematosus with positive anti-Ro antibodies following palbociclib and letrozole treatment: A case report and literature review.

Drug-induced subacute cutaneous lupus erythematosus (DI-SCLE) is an uncommon but well-described phenomenon, most often seen in association with antihypertensives and antifungal medications. In recent years, rare reports of DI-SCLE have been described in patients being treated with targeted therapies. Herein, we describe a case of DI-SCLE in association with palbociclib and letrozole treatment for metastatic breast cancer. This report is the first known case of DI-SCLE with positive anti-Ro antibodies in this setting. We also summarize the literature describing DI-SCLE in association with targeted therapies to date and its possible association with dysregulation of the vascular endothelial growth factor pathway.