Primary Systemic Amyloidosis Presenting as Extensive Cutaneous Ulceration

Cutaneous deposits

: The cutaneous deposition disorders are a group of unrelated conditions characterized by the accumulation of either endogenous or exogenous substances within the skin. These cutaneous deposits are substances that are not normal constituents of the skin and are laid down usually in the dermis, but also in the subcutis, in a variety of different circumstances. There are 5 broad categories of cutaneous deposits. The first group includes calcium salts, bone, and cartilage. The second category includes the hyaline deposits that may be seen in the dermis in several metabolic disorders, such as amyloidosis, gout, porphyria, and lipoid proteinosis. The third category includes various pigments, heavy metals, and complex drug pigments. The fourth category, cutaneous implants, includes substances that are inserted into the skin for cosmetic purposes. The fifth category includes miscellaneous substances, such as oxalate crystals and fiberglass. In this article, the authors review the clinicopathologic characteristics of cutaneous deposition diseases, classify the different types of cutaneous deposits, and identify all the histopathologic features that may assist in diagnosing the origin of a cutaneous deposit.

Significant association between renal function and amyloid-positive area in renal biopsy specimens in AL amyloidosis

Background

The kidney is a major target organ for systemic amyloidosis that often affects the kidney including proteinura, and elevated serum creatinine (Cr). The correlation between amount of amyloid deposits and clinical parameters is not known. The aim of this study was to clarify correlation the amyloid area in all renal biopsy specimen and clinical parameters.

Methods

Fifty-eight patients with an established diagnosis of AL amyloidosis participated in the study. All patients showed amyloid deposits in renal biopsies. We retrospectively investigated the correlation between clinical data and amyloid occupied area in whole renal biopsy specimens.

Results

The area occupied by amyloid was less than 10% in 57 of the 58 patients, and was under 2% in 40. For statistical analyses, %amyloid-positive areas were transformed to common logarithmic values (Log₁₀%amyloid). Cr showed significant correlation with Log₁₀%amyloid and estimated glomerular filtration rate (eGFR) showed the significant negative correlation. Patient age, cleatinine clearance (Ccr), blood urea nitorogen, and urinary protein was not significantly correlated with Log₁₀%amyloid. The correlation with other clinical factors such as sex, and serum concentrations of total protein, albumin, immunoglobulins, compliments was evaluated. None of these factors significantly correlated with Log₁₀%amyloid. According to sex- and age- adjusted multiple linear regression analysis, Log₁₀%amyloid had significant positive association with Cr and significant negative association with eGFR.

Conclusion

There is significant association between amyloid-positive area in renal tissue and renal function, especially Cr and eGFR. The level of Cr and eGFR may be a marker of amount of amyloid in renal tissue.

Cutaneous amyloidosis: a concept review

Concepts and semantics are crucial for good communication between clinicians and pathologists. Amyloidosis was described more than 150 years ago. Therefore, the terminology related to it is abundant, varied, and sometimes complex. In this report, we intend to discuss several terms related to the disease, with special emphasis on cutaneous amyloidosis. We present a review, from Virchow to present, of the concepts related to amyloidosis: its nature, the classification of cutaneous forms of the disease, and the techniques used in its diagnosis.

The blue man: a novel cutaneous manifestation of systemic amyloidosis

Multiple cutaneous manifestations of amyloidosis have been described, and include periorbital purpura, plaques, nodules, and papules. Blue skin tint is not a previously described feature of cutaneous amyloidosis. We report the clinical case of a patient with known multiple myeloma and amyloidosis of the gastrointestinal tract who presented with progressive "blueness" of the skin. Dermatopathological examination and mass spectrometry of a skin biopsy specimen revealed the presence of subcutaneous amyloid light chain (AL) deposition. We believe this to be the first reported case of blue skin resulting from systemic amyloidosis.