The sarcoidal granuloma: A unifying hypothesis for an enigmatic response

Ichthyosiform sarcoidosis: Report of a case and comprehensive review of the literature

Sarcoidosis is a disease that can affect a multitude of organs and manifest as cutaneous disease. Cutaneous manifestations of sarcoidosis vary widely in morphology, earning the nickname of "great imitator," and the diagnosis often requires clinicopathologic correlation and additional laboratory and radiographic workup. We present the case of a 42-year-old African American woman with ichthyosiform sarcoidosis on the bilateral lower extremities. As one of the rarest specific variants of cutaneous sarcoidosis, ichthyosiform is understudied and has been primarily documented in case reports and series. We undertake a comprehensive review of the literature to identify key clinicopathologic features including the characterization of sites of cutaneous and systemic involvement, as well as typical histopathological findings. Lower extremities were the most involved body site (85.7%). Extracutaneous organ involvement centered around pulmonary (65.7%), lymph node (57.1%), and ocular (31.4%) involvement. Of the histopathological features reported, hyperkeratosis (51.4%) and diminished stratum granulosum (62.9%) were most frequently reported in conjunction with dermal granulomas (100%). We hope that these findings will serve to aid clinicopathological correlation and accurate diagnosis of ichthyosiform sarcoidosis.

It's elemental! Siliceous diatom frustules producing sarcoid-like granulomas in the subcutis

Silica granulomas have been described on the skin and are rare; however, this is the first report of a sarcoid-like granulomatous reaction because of siliceous diatom frustules in the subcutis, making this an unprecedented case. A 41-year-old female presented with a subcutaneous nodule on the right forearm clinically suggestive of cyst, foreign body, or lipoma. Excisional biopsy revealed subcutis with a sarcoid-like granulomatous reaction in a background of fibrosis, containing abundant semitransparent, exquisitely geometric particles, mildly refringent under polarized light, highlighted by phase contrast microscopy; special stains were negative for microorganisms. Definitive characterization of the peculiar fragments was accomplished by confocal laser microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy, revealing them as diatom frustules made of silicon dioxide (SiO₂ ) or silica. Diatoms are unicellular algae, their skeletons (frustules) made of silica have collected on the bottom of rivers, lakes, and oceans for thousands or millions of years and form what we know as diatomite or diatomaceous earth, which is widely used in different industries and easily available in the market. The mechanism whereby diatom frustules gained access to the patient's subcutis is enigmatic.

Immunocompromised cutaneous district, isotopic, and isopathic phenomena-Systematic review

BACKGROUND

Although the development of lesions in skin areas that have undergone injury has long been known, understanding of its pathogenesis is limited. Depending on their peculiarities, those events have been described as isomorphic, reverse isomorphic, pseudoisomorphic, isotopic, and isopathic phenomena. Ruocco's immunocompromised cutaneous district (ICD) concept was proposed to include all those phenomena.

AIMS

We performed a systematic review and critically evaluated the current understanding about ICD and its relationship with the isotopic and isopathic phenomena.

METHODS

To illustrate the complexity of the theme, we present a case of subclinical leprosy, whose manifestation was brisk in an old tattoo. The possible interaction between the approached phenomena, acting in the genesis of the disease, made this a pertinent study. The research was conducted under the PRISMA-P guidelines, in seven biomedical databases between 1996 and 2018. The eligibility criteria were systematic reviews, meta-analyses, clinical studies, and case series, written in English, French, Italian, Portuguese, or Spanish.

RESULTS

Using standardized keywords, 1220 articles were identified. After applying the eligibility criteria, 53 studies were selected.

CONCLUSION

This review ratifies that all these phenomena are aspects of one single condition. They can be integrated into the ICD concept with the pathogenesis including: (a) neural damage (peripheral or central) and (b) chronic lymphedema. Both may change the local neuroimmune interaction. The identification of these phenomena and the understanding of their pathogenesis are of paramount importance, to define the diagnosis and choose the therapeutic strategy.

Coexisting sarcoidal granulomatous inflammation and diffuse tenosynovial giant cell tumor of the knee after a total knee replacement: a case report

Sarcoidosis is a systemic inflammatory disorder characterized by non-caseating granulomas, predominantly involving lung, mediastinal lymph nodes and other organs. Synovium involvement is infrequent, and as far as we know, involvement of a periprosthetic membrane has not been reported in the English literature. Intra-articular diffuse tenosynovial giant cell tumor ("conventional diffuse pigmented villonodular synovitis") is an uncommon, locally aggressive neoplasm with few previous case reports in which it arose in periprosthetic tissues after knee arthroplasty. We describe a unique case of an intraarticular mass next to a total knee prosthesis implanted 6 years ago in a patient with a history of pulmonary sarcoidosis. Clinically, this 67-year-old gentleman presented with progressive left knee pain, effusion and marked instability. MRI showed a large complex effusion with synovial thickening in the supra patella recess and the medial and lateral gutters. In addition, a large multilobulated mass with mixed low and high signal intensity was present in the posterior joint space, extending into the popliteal area. A two-stage operation was performed. Histologically, the mass from the posterior joint space showed characteristic features of diffuse tenosynovial giant cell tumor, while the synovium from the anterior compartment demonstrated sarcoidal granulomatous inflammation. Orthopaedic wear debris was found within the giant cells of these sarcoidal granulomata. The histologic features are different from those "usual" macrophage reactions to the particles of debris. In this article, we also included two optional links (highlighted in blue in the figures) to digital whole slide image (WSI), which allow the readers to navigate the entire microscope slides.

The lady with the dragon tattoo

BACKGROUND

Though the skin is affected in sarcoidosis in about one-third of cases, granulomatous tattoo reactions are an unusual manifestation of the disease. It is important phenomenon to recognize, as it frequently leads to the diagnosis of systemic sarcoidosis.

CASE PRESENTATION

A 35-year-old Caucasian female with multiple tattoos presented with a 5-week history of tenderness of the black dye in a tattoo depicting a dragon. She also described a 15-month history of fatigue, polyarthralgia, and mild dyspnea. Skin biopsy demonstrated multiple dermal non-caseating granulomata with associated tattoo ink. Further investigation revealed the presence of systemic sarcoidosis. Her symptoms and skin changes improved with conservative management.

CONCLUSION

Sarcoidal tattoo reactions in those without systemic sarcoidosis are a rare occurrence, and their presence should prompt a search for systemic involvement. The accurate identification of skin involvement in sarcoidosis is important, as it tends to occur early in the course of disease, and the skin is a readily accessible site for biopsy, allowing for prompt diagnosis.

Histologic features of granulomatous skin diseases. Part 1: Non-infectious granulomatous disorders

Granulomatous disorders affecting the skin belong to a heterogeneous group of diseases. With the exception of granulomas induced by infectious agents or foreign bodies, the etiopathogenesis of granulomatous disorders is still poorly understood. The knowledge of histopathologic changes is of great importance for understanding clinical presentation and disease course.