|THROUGH THE DERMOSCOPE
|Year : 2018 | Volume
| Issue : 1 | Page : 57-58
Macular amyloidosis in a middle-aged woman
Piyush Kumar1, Shekhar Neema2, Niloy Pathak3
1 Department of Dermatology, Katihar Medical College, Katihar, Bihar
2 Department of Dermatology, Command Hospital, Kolkata, West Bengal, India
3 Department of Pathology, Command Hospital, Kolkata, West Bengal, India
|Date of Web Publication||29-May-2018|
Katihar Medical College, Katihar, Bihar
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kumar P, Neema S, Pathak N. Macular amyloidosis in a middle-aged woman. Pigment Int 2018;5:57-8
A 37-year-old homemaker, otherwise healthy, presented with a dark skin pigmentation of the upper back, arms, and lower legs. The pigmentation first appeared around 15 years back and gradually progressed to the present status. The patient did not complain of any discomfort except for pruritus in the region, which used to intensify in warm weather. She could not recollect the presence of any rash at the affected sites prior to the development of pigmentation. A dermatologic examination showed a grayish black rippled pigmentation on the skin over the upper back, extensors of forearms, and lower legs. The surface was slightly reticular and ruffled [Figure 1].
Macular amyloidosis, lichen planus pigmentosus, and postinflammatory hyperpigmentation were considered as clinical differentials. A dermoscopic examination of the lesions over the upper back showed brown clods and radiating brown lines from the clod. Such a pattern has been described as “Hub and Spoke” pattern [Figure 2].
|Figure 2: Dermoscopy shows brown clods and radiating brown lines described as “Hub and Spoke” pattern (blue arrow)|
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Histopathologic examination of the lesion on the back showed a slight enlargement of the dermal papillae containing a homogeneous, amorphous material [Figure 3]. Other notable findings were melanophages and scant lymphohistiocytic infiltrate in the papillary dermis. Congo red staining was not performed.
|Figure 3: Dermal papilla showing homogeneous deposition of eosinophilic material, suggestive of amyloid (H&E, 400×)|
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Amyloidosis is a group of disorders characterized by the accumulation of fibrillar material (amyloid) in the tissues. Primary cutaneous amyloidosis (PCA), characterized by the accumulation of amyloid material exclusively in the skin, needs to be differentiated from systemic amyloidosis, wherein the amyloid is deposited in various internal organs in addition to the skin. In PCA, the source of amyloid material has been demonstrated as keratin intermediary filaments by immunohistochemical studies. PCA is clinically characterized by two distinct presentations—macular amyloidosis and lichen amyloidosis—and is believed to result from localized trauma in the form of continuous friction, scratching or manipulation, or the use of sponges, brushes, etc., during bath. It has been proposed that mechanical damage to the skin leads to the apoptosis of basal layer keratinocytes and, thereafter, the release of keratin into the dermis. Inside the macrophages, after being phagocytosed, there occurs a structural transformation of keratins from previously α-structure into β-pattern proteins (the hallmark of amyloid proteins), which resist physiological degradation and, thus, keep accumulating over time. Dermoscopy is an important tool to diagnose cutaneous amyloidosis and can help differentiate it from frictional melanoses, which show reticular network without central hub, lichen planus pigmentosus, which shows pseudoreticular pigment network, slate-gray-to-blue dots and globules, and perifollicular and perieccrine pigment deposition.[,,]
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Vijaya B, Dalal BS, Manjunath GV. Primary cutaneous amyloidosis: A clinico-pathological study with emphasis on polarized microscopy. Indian J Pathol Microbiol 2012;55:170. [Full text]
Chuang YY, Lee DD, Lin CS, Chang YJ, Tanaka M, Chang YT et al.
Characteristic dermoscopic features of primary cutaneous amyloidosis: A study of 35 cases. Br J Dermatol 2012;167:548-54.
Neema S, Jha A. Lichen planus pigmentosus. Pigment Int 2017;4:48-9. [Full text]
[Figure 1], [Figure 2], [Figure 3]