Cutaneous and hepatic vascular lesions due to a recurrent somatic GJA4 mutation reveal a pathway for vascular malformation

The term “cavernous hemangioma” has been used to describe vascular anomalies with histology featuring dilated vascular spaces, vessel walls consisting mainly of fibrous stromal bands lined by a layer of flattened endothelial cells, and an irregular outer rim of interrupted smooth muscle cells. Hepatic hemangiomas (HHs) and cutaneous venous malformations (VMs) share this histologic pattern, and we examined lesions in both tissues to identify genetic drivers. Paired whole-exome sequencing (WES) of lesional tissue and normal liver in HH subjects revealed a recurrent GJA4 c.121G>T (p.Gly41Cys) somatic mutation in four of five unrelated individuals, and targeted sequencing in paired tissue from 9 additional HH individuals identified the same mutation in 8. In cutaneous lesions, paired targeted sequencing in 5 VMs and normal epidermis found the same GJA4 c.121G>T (p.Gly41Cys) somatic mutation in three. GJA4 encodes gap junction protein alpha 4, also called connexin 37 (Cx37), and the p.Gly41Cys mutation falls within the first transmembrane domain at a residue highly conserved among vertebrates. We interrogated the impact of the Cx37 mutant via lentiviral transduction of primary human endothelial cells. We found that the mutant induced changes in cell morphology and activated serum/glucocorticoid-regulated kinase 1 (SGK1), a serine/threonine kinase known to regulate cell proliferation and apoptosis, via non-canonical activation. Treatment with spironolactone, an inhibitor of angiogenesis, suppressed mutant SGK1 activation and reversed changes in cell morphology. These findings identify a recurrent somatic GJA4 c.121G>T mutation as a driver of hepatic and cutaneous VMs, revealing a new pathway for vascular anomalies, with spironolactone a potential pathogenesis-based therapy.

Cutaneous Involvement in Plasma Cell Myeloma

OBJECTIVES

Plasma cell myeloma (PCM) involving skin is rare and occurs in 1% to 4% of patients with PCM. We evaluated the clinicopathologic features, cytogenetic findings and clinical follow-up in a series of PCM cases with cutaneous involvement.

METHODS

Cases of PCM with cutaneous involvement were retrospectively reviewed with clinical data.

RESULTS

Skin involvement in PCM occurred in older individuals (mean, 75 years) and was more frequent in men (7/10 patients). All cases showed bone marrow involvement preceding the cutaneous lesions. Histopathologically, the infiltrate was plasmacytic (n = 5) or primitive or plasmablastic (n = 4), and 1 case showed predominantly lymphoplasmacytic features with cyclin D1 immunoreactivity and CCND1 gene rearrangement. Concurrent amyloid deposition was seen in one biopsy, and another case demonstrated coexisting squamous cell carcinoma. The most common immunophenotype was CD138+, CD20-, and CD56+ with light chain restriction. Cytogenetic analysis (available for 7 cases) showed multiple hyperdiploid abnormalities. Follow-up was available for 8 cases (mean, 42 months; range, 11-156 months) and showed short-term disease-related death in 7 of 8 patients.

CONCLUSIONS

Cutaneous involvement in PCM demonstrates a diverse cytomorphologic spectrum with plasmacytic, plasmablastic, or lymphoplasmacytic features and may show concurrent amyloid deposition or neoplasms such as squamous cell carcinoma. Cutaneous involvement typically occurs late in the course of the disease and likely portends poor outcome.

Response to Tembhre et al.: 'Enhanced expression of angiotensin-converting enzyme 2 in psoriatic skin and its upregulation in keratinocytes by interferon-γ: implication of inflammatory milieu in skin tropism of SARS-CoV-2'

Linked Article: Tembhre et al. Br J Dermatol 2021; 184:577–579.

Discordant anti-SARS-CoV-2 spike protein and RNA staining in cutaneous perniotic lesions suggests endothelial deposition of cleaved spike protein

BACKGROUND

Prior studies have shown the presence of immunohistochemical staining for the SARS-CoV-2 spike protein (SP) in endothelial cells and eccrine epithelium of acral perniosis classified as "COVID toes." Yet, other studies have been unable to detect SARS-CoV-2 RNA in skin biopsies of "COVID toes" by reverse-transcriptase polymerase chain reaction testing.

OBJECTIVE

In order to address these apparently conflicting findings, we compared detection of SARS-CoV-2 SP, through RNA in situ hybridization (ISH) vs immunohistochemistry (IHC), in skin biopsies of acral perniotic lesions presenting during the COVID-19 pandemic.

RESULTS

Three of six cases showed positive immunohistochemical labeling of endothelial cells, with one of three cases with sufficient depth also having labeling of eccrine glands, using an anti-SP SARS-CoV-2 antibody. These three cases positive with IHC were negative for SP by RNA ISH.

CONCLUSION

While the gold standard for detection of SARS-CoV-2 in tissue sections has yet to be determined, the detection of SARS-CoV-2 SP alone without spike RNA suggests that cleaved SP may be present in cutaneous endothelial cells and eccrine epithelium, providing a potential pathogenetic mechanism of COVID-19 endotheliitis.

Perniosis during the COVID-19 pandemic: Negative anti-SARS-CoV-2 immunohistochemistry in six patients and comparison to perniosis before the emergence of SARS-CoV-2

BACKGROUND

Acral inflammatory lesions that have some resemblance to idiopathic or autoimmune-associated perniosis (chilblains) have been described in multiple countries during the COVID-19 pandemic.

METHODS

We examined histopathologic findings in six consecutive such cases from five patients received in mid-May to mid-June of 2020, evaluating immunohistochemical staining for the SARS-CoV-2 nucleocapsid protein. We compared these six cases to eight cases diagnosed as perniosis between January and June of 2019.

RESULTS

Five of six lesions with perniosis-like histopathology during the COVID-19 pandemic had distinctive tight cuffing of lymphocytes; intravascular material was present in one case. SARS-CoV-2 immunohistochemical staining using an antibody directed at the nucleocapsid protein was negative in all six cases. Only one of eight specimens with microscopic findings of perniosis received prior to the COVID-19 pandemic had tightly cuffed perivascular lymphocytes, and none had obvious intravascular occlusion.

CONCLUSIONS

A tightly cuffed pattern of perivascular lymphocytes is a feature of perniosis during the COVID-19 pandemic. The absence of SARS-CoV-2 nucleocapsid protein in these cases suggests against the virus being directly present in these lesions.

A detailed analysis of the distribution, morphology, and histopathology of complex purpura in hospitalized patients: A case series of 68 patients

BACKGROUND

Purpura in inpatients commonly leads to dermatologic consultation. The differential diagnosis is broad and algorithms are intricate.

OBJECTIVE

We evaluated inpatient consultations for complex purpura to document the most common diagnoses and to validate the true diagnostic utility of histopathology, clinical morphology, and distribution.

METHODS

We reviewed a case series of 68 inpatients during a 4-year period with a dermatologic consultation for purpura and biopsy findings of vasculitis or microvascular occlusion.

RESULTS

Key features of complex purpura are nonbranching (round) versus branching (retiform) morphology, dependent versus acral or generalized distribution, and leukocytoclastic vasculitis versus microvascular occlusion (with emphasis on depth of involvement). Dependent nonbranching purpura with only superficial vessels involved by leukocytoclastic vasculitis was most often due to IgA vasculitis or cutaneous single-organ small-vessel vasculitis. In contrast, deeper involvement by leukocytoclastic vasculitis was suggestive of systemic disease (eg, antineutrophil cytoplasmic antibody-associated vasculitis). Branching purpura was concerning, with greater than 90% sensitivity and specificity for microvascular occlusion and associated high mortality (≈50%). The majority of patients who died had acral branching lesions.

LIMITATIONS

Small sample size, inpatients at a tertiary care center, and retrospective nature are some limitations.

CONCLUSION

Nonbranching dependent purpura corresponded to leukocytoclastic vasculitis, with the most common diagnoses being IgA vasculitis or skin-limited small-vessel vasculitis; patients with deep involvement often had systemic diseases. In this series, branching purpura was due to microvascular occlusion rather than medium-vessel vasculitis, and had associated high mortality.

Diltiazem-associated Photodistributed Hyperpigmentation

Diltiazem is a calcium-channel blocker commonly used for the treatment of hypertension. Common adverse effects include dizziness, headache, and edema. Fewer than 20 cases of diltiazem-associated photodistributed hyperpigmentation have been reported in the literature. Here, we present the case of a 71-year-old woman with new-onset facial hyperpigmentation 6 months after initiating treatment with diltiazem.

Intravascular Large B-Cell Lymphoma: Clinical and Histopathologic Findings

Intravascular large B-cell lymphoma (IVLBCL) is a rare subset of extranodal non-Hodgkin lymphoma characterized by neoplastic lymphocytes within the lumina of small to medium-sized blood vessels. IVLBCLs are B-cell tumors that can present in essentially any organ system, including the skin. Cutaneous manifestations vary greatly and can mimic other skin disease which may delay diagnosis; in the absence of skin lesions, blind skin biopsies can be utilized for diagnosis. Early studies suggested that IVLBCL is a very aggressive lymphoma with high overall mortality rate and short survival times. However, earlier diagnosis and use of new treatment modalities have shown promise in recent studies. This case series illustrates the heterogeneity of clinical and pathologic presentations of this uncommon lymphoma.

Second-Hit, Postzygotic PMVK and MVD Mutations in Linear Porokeratosis

Importance

Linear porokeratosis features linear and whorled configurations of keratotic papules and plaques, with coronoid lamellae present on histologic examination. Because linear porokeratosis manifests in the lines of Blaschko representing the dorsoventral migration patterns of keratinocyte precursors, it has been suggested that postzygotic somatic mutation underlies the disease. However, no genetic evidence has supported this hypothesis to date.

Objective

To identify genetic mutations associated with linear porokeratosis.

Design, Setting, and Participants

Paired whole-exome sequencing of affected skin and blood/saliva samples from 3 participants from 3 academic medical centers with clinical and histologic diagnoses of linear porokeratosis.

Interventions or Exposures

Whole-exome sequencing of paired blood/saliva and affected tissue samples isolated from linear porokeratosis lesions.

Main Outcomes and Measures

Germline and somatic genomic characteristics of participants with linear porokeratosis.

Results

Of the 3 participants, 2 were male. Participant ages ranged from 5 to 20 years old. We found a combination of a novel germline mutation and a novel somatic mutation within affected tissue in all cases. One participant had a germline heterozygous PMVK c.329G>A mutation and a somatic copy-neutral loss of heterozygosity confined to the lesional skin, while a second had a germline heterozygous PMVK c.79G>T mutation and an additional PMVK c.379C>T mutation in the lesional skin. In a third participant, there was a germline splice-site mutation in MVD (c.70 + 5G>A) and a somatic deletion in MVD causing frameshift and premature codon termination within the lesional skin (c.811_815del, p.F271Afs*33 frameshift).

Conclusions and Relevance

Our findings suggest that linear porokeratosis is associated with the presence of second-hit postzygotic mutations in the genes that encode enzymes within the mevalonate biosynthesis pathway, and provide further evidence that the mevalonate pathway may be a potential target for therapeutic intervention in porokeratosis.

Histopathologic findings characteristic of CARD14-associated papulosquamous eruption

BACKGROUND

Pathogenic mutations in caspase recruitment domain-containing protein 14 (CARD14) lead to CARD14-associated papulosquamous eruption, which shares clinicopathologic findings with psoriasis and pityriasis rubra pilaris. We aimed to describe distinguishing histopathologic features of CARD14-associated papulosquamous eruption.

METHODS

This retrospective study examined the histopathologic features of specimens from patients with confirmed CARD14-associated papulosquamous eruption and adult patients with plaque psoriasis and pityriasis rubra pilaris.

RESULTS

Lesional skin biopsies from patients with CARD14-associated papulosquamous eruption consistently showed alternating checkerboard parakeratosis and orthokeratosis, acanthosis without acantholysis, and dilated vessels in the dermal papillae, with some cases also showing follicular plugging.

CONCLUSION

CARD14-associated papulosquamous eruption has a range of findings, with a predominance of features typically associated with pityriasis rubra pilaris.

Hypergranulotic dyscornification: 30 cases of a striking epithelial reaction pattern

BACKGROUND

Hypergranulotic dyscornification (HD) is a rarely reported histological reaction pattern that may be observed in solitary benign keratoses.

OBJECTIVE AND METHODS

We retrospectively reviewed all cases described as displaying "hypergranulotic dyscornification" at our institution between January 1st 1990 to September 1st 2018. We excluded cases that on retrospective review displayed changes of epidermolytic hyperkeratosis. We conducted electron microscopy (EM) of two lesions.

RESULTS

Thirty cases were identified in our search. Eleven patients were men and 19 were women. Their mean age was 56.9 ± 21.2 years. In contrast to previous reports, we found that HD does not spare the head and neck area. Frequent clinical impressions were inflamed seborrheic keratosis, Bowen disease or inflamed verruca. The most distinctive histopathologic finding was the presence of a prominent granular layer with clumped perinuclear keratohyaline granules. Some cases had mounds of rounded, anucleate glassy eosinophilic corneocytes in the stratum corneum. We observed one case of incidental HD occurring in an epidermoid cyst. EM of HD showed dense perinuclear bands which appeared to match areas of positive staining by keratin immunohistochemistry, without evidence of pale cytoplasmic areas devoid of keratin filaments, characteristic of epidermolytic hyperkeratosis.

CONCLUSION

HD is a reproducible finding in some benign keratoses, probably because of abnormal keratinization. Awareness of this unique reaction pattern will help prevent misdiagnosis.

Cutaneous Squamous Cell Carcinomas in Solid Organ Transplant Recipients Compared With Immunocompetent Patients

Importance

Solid organ transplant recipients (SOTRs) have a 100-fold increased risk of squamous cell carcinoma (SCC), and they may develop more aggressive SCCs compared with immunocompetent individuals.

Objective

To compare outcomes associated with aggressive behavior of SCC in SOTRs and high-risk immunocompetent patients.

Design, Setting, and Participants

A retrospective cohort study of 58 SOTRs and 40 immunocompetent patients evaluated at the Yale Transplant Dermatology Clinic in New Haven, Connecticut, who had at least 1 SCC confirmed histopathologically between January 1, 2008, and December 31, 2015. Cumulative follow-up time for this study was 369 patient-years.

Exposure

Immunosuppressive medication regimen for SOTRs.

Main Outcomes and Measures

The primary outcome measure was tumor depth of SCC. Secondary outcome measures that reflected tumor aggressiveness included perineural invasion, regional metastases, nodal metastases, disease-specific death, and overall death.

Results

Of the 58 SOTR study participants, 14 were women and 44 were men; the mean (SD) age was 61.3 (8.4) years. Of the 40 immunocompetent study participants, 16 were women and 24 were men; the mean (SD) age was 69.8 (10.9) years, resulting in a statistically significant difference from the SOTR group. The mean (SD) number of years that SOTRs were immunosuppressed was 14.6 (9.2) years (range, 2-37 years). The SOTR and immunocompetent groups were statistically comparable regarding race and sex, patient care, follow-up time, numbers of skin lesions, and field cancerization and chemopreventive therapies. The SOTR group had a significantly higher annual frequency of visits (mean [SD], 4 [2] vs 3 [2] office visits per patient per year, P = .02) and annual biopsy rates (mean [SD], 6 [4] vs 5 [3] biopsies per patient per year, P = .04). The SOTRs developed SCCs that did not appear to be significantly more aggressive than those found in the immunocompetent control group. These SOTRs also did not develop significantly thicker tumors than the immunocompetent control group (median [IQR] tumor depth, 1.30 [0.90-1.60] mm in 35 SOTRs vs 1.22 [1.10-1.60] mm in 20 immunocompetent patients).

Conclusions and Relevance

The increased risk and the potential for aggressive behavior of SCCs in SOTRs may be successfully managed at a level comparable to that in high-risk immunocompetent individuals through close adherence to current dermatologic surveillance recommendations and a marginally lower threshold for biopsy of suspicious lesions for SOTRs.

Coccygeal Polypoid Eccrine Nevus

Skin tags are fairly common lesions usually seen in adults on the neck and in body folds. The sacrococcygeal region is an unusual location for skin tags in children and may represent a congenital malformation of the spine or an isolated skin lesion. In this review, we summarize the clinical presentation, histopathologic changes, and differential diagnosis of coccygeal polypoid eccrine nevus as a rare cause of sacrococcygeal papules in children.

Cutaneous immunohistochemical staining pattern of p53β isoforms

p53 is considered the guardian of the genome and as such has numerous functions. The TP53 gene is the most commonly mutated gene in cancer, and yet the exact biological significance of such mutations remains unclear. There are at least 12 different isoforms of p53, and the complexity of the p53 pathway may be in part related to these isoforms. Prior research has often not teased out what isoforms of p53 are being studied, and there is evidence in the literature that p53 isoforms are expressed differently. In this paper, we document the staining pattern of p53β isoforms in the skin and correlate it with mutational status in a subgroup of squamous proliferations of the skin. p53β isoforms are present in the cytoplasm of the differentiated layer of the epidermis and hair follicles (granular layer, infundibular and isthmus-catagen). p53β isoforms are diffusely expressed within the cytoplasm of well-differentiated squamous tumours with tetramerisation (C-terminal) domain mutations in TP53 Our results lend support to p53β isoforms being a marker of differentiation in keratinocytes.

Well-differentiated neuroendocrine tumors in skin: Terminology and diagnostic utility of cytokeratin 5/6 and p63

BACKGROUND

Well-differentiated neuroendocrine tumors (WDNETs) in skin include metastases from visceral primary sites and very uncommonly, primary cutaneous carcinoid tumors. Cutaneous WDNET may present a diagnostic challenge and in particular can be mistaken for a benign skin adnexal tumor. In contrast to cutaneous adnexal tumors, metastatic adenocarcinomas to the skin are cytokeratin 5/6 (CK5/6) and p63 negative in the majority of cases. It is unclear if failure to stain with CK5/6 and p63 would be helpful in differentiating WDNETs from cutaneous adnexal neoplasms.

METHODS

We reviewed 10 cases of cutaneous WDNETs (8 cases of metastatic disease and 2 presumed primary carcinoid tumors of the skin) and performed immunohistochemical stains for CK5/6 and p63 on all cases.

RESULTS

All 10 cases were negative with both CK5/6 and p63.

CONCLUSION

Negative staining for CK5/6 and p63 can be helpful to distinguish WDNETs from cutaneous adnexal neoplasms. It is important to consider WDNETs in the differential diagnosis of cutaneous adnexal neoplasms as low-grade tumors may be the first sign of aggressive metastatic disease.

Predicting non-melanoma skin cancer via a multi-parameterized artificial neural network

Ultraviolet radiation (UVR) exposure and family history are major associated risk factors for the development of non-melanoma skin cancer (NMSC). The objective of this study was to develop and validate a multi-parameterized artificial neural network based on available personal health information for early detection of NMSC with high sensitivity and specificity, even in the absence of known UVR exposure and family history. The 1997-2015 NHIS adult survey data used to train and validate our neural network (NN) comprised of 2,056 NMSC and 460,574 non-cancer cases. We extracted 13 parameters for our NN: gender, age, BMI, diabetic status, smoking status, emphysema, asthma, race, Hispanic ethnicity, hypertension, heart diseases, vigorous exercise habits, and history of stroke. This study yielded an area under the ROC curve of 0.81 and 0.81 for training and validation, respectively. Our results (training sensitivity 88.5% and specificity 62.2%, validation sensitivity 86.2% and specificity 62.7%) were comparable to a previous study of basal and squamous cell carcinoma prediction that also included UVR exposure and family history information. These results indicate that our NN is robust enough to make predictions, suggesting that we have identified novel associations and potential predictive parameters of NMSC.

Dermatomyositis: Histopathologic findings of parakeratosis and dermal edema revisited

The cutaneous manifestations of dermatomyositis range from classical in the case of heliotrope rash and Gottron papules to less common papulosquamous and edematous/vesiculobullous lesions; histopathologic descriptions are dominated by interface dermatitis. We present a case of dermatomyositis with a combination of common and rare skin findings, both clinically and histologically. Increased awareness of papulosquamous and edematous lesions of dermatomyositis can help direct patient care. Although uncommon, confluent parakeratosis and dermal edema can be manifestations of dermatomyositis.

Metastatic serous carcinoma presenting as inflammatory carcinoma over the breast-Report of two cases and literature review

Non-mammary metastases involving breast are rare and most commonly involve the breast parenchyma. Infrequently, metastasis from an extramammary primary site presents as inflammatory carcinoma over the breast. Diagnosis of such lesions can be challenging, especially in patients with coexisting primary breast carcinoma. Few such cases have been described in literature; however, none of the previously reported cases had a prior history of primary breast carcinoma. We present 2 patients with history of breast carcinoma and serous carcinoma of ovarian/peritoneal origin that presented with inflammatory carcinoma over the breast. Biopsies from breast tissue showed atypical cells in the dermis forming cords and papillary structures. Histopathologic differential diagnosis included infiltrating ductal carcinoma of breast origin and metastatic serous carcinoma. Immunohistochemical studies showed that the tumor cells were positive for markers of ovarian origin such as PAX-8 and CA-125 and negative for breast markers such as GATA-3, thus supporting the diagnosis. In summary, we describe the unusual presentation of metastatic serous carcinoma as inflammatory carcinoma over breast and discuss the diagnostic challenges in patients with coexisting primary breast and ovarian malignancies. We also review the morphologic features of tumors of breast and ovarian origin and the immunohistochemical stains to differentiate these 2 entities.