Secondary Cutaneous Amyloidosis in a Patient with Mycosis Fungoides

Histopathological Insights into Primary Localized Cutaneous Amyloidosis: A Case Series

Background Primary Localized Cutaneous Amyloidosis (PLCA) is a rare disorder characterized by amyloid deposition in the skin without systemic involvement. It includes lichen amyloidosis (LA), macular amyloidosis (MA), and biphasic amyloidosis. The pathogenesis is linked to chronic friction, keratinocyte damage, and in some cases, genetic predisposition. Histopathological examination remains the gold standard for diagnosis. Here, we present a series of nine cases of PLCA. Objective This case series aims to establish a correlation between the clinical manifestations of PLCA and the histopathological findings, including special stains, to improve diagnostic accuracy. Identifying these correlations is vital for differentiating PLCA subtypes, guiding treatment strategies, and understanding the underlying pathogenic mechanisms.  Methods A retrospective analysis was conducted at Panimalar Medical College and Hospital, Chennai, India, reviewing nine biopsy-confirmed PLCA cases from January 2023 to December 2024. Clinical data, histopathological features, and staining characteristics (hematoxylin & eosin, Congo red, and crystal violet) were analyzed. Results Out of nine cases, LA was the predominant subtype (seven cases), followed by MA (two cases). Female predominance was observed (male-to-female ratio was 1:2), with an age range of 39-65 years. The upper limbs were the most frequently affected site. Pruritus was exclusively seen in LA, while hyperpigmentation was present in all cases. Histopathological analysis revealed amyloid deposits in the papillary dermis, epidermal hyperplasia, and inflammatory infiltration in LA. Congo red staining demonstrated characteristic apple-green birefringence under polarized light, confirming amyloid deposition. Conclusion The study reinforces the clinical and histopathological distinctiveness of PLCA subtypes. LA is strongly associated with chronic friction and pruritus, whereas MA presents with asymptomatic hyperpigmentation. Congo red and crystal violet stains remain indispensable for diagnosis. Despite advances in histopathology, therapeutic options remain limited, necessitating further research into targeted molecular treatments and genetic predispositions.

Integrated Network-Based Analysis of Diseases Associated with Amyloid Deposition Through a Disease-Protein-Drug Network

Background: At present, the complexity that governs the associations between different biological entities is understood better than ever before, owing to high-throughput techniques and systems biology. Networks of interactions are necessary not only for the visualization of these complex relationships but also because their analysis tends to be valuable for the extraction of novel biological knowledge. Methods: For this reason, we constructed a disease-protein-drug network, focusing on a category of rare protein-misfolding diseases, known as amyloidoses, and on other pathological conditions also associated with amyloid deposition. Apart from the amyloidogenic proteins that self-assemble into fibrils, we also included other co-deposited proteins found in amyloid deposits. Results: In this work, protein-protein, protein-drug, and disease-drug associations were collected to create a heterogenous network. Through disease-based and drug-based analyses, we highlighted commonalities between diseases and proposed an approved drug with prospects of repurposing. Conclusions: The identified disease associations and drug candidates are proposed for further study that will potentially help treat diseases associated with amyloid deposition.

Basal Cell Carcinoma Associated with Secondary Localized Cutaneous Amyloid Deposits: Case Report and Review

Amyloid deposition has been observed in tissue specimens of basal cell carcinomas. A 68-year-old man with a nodular basal cell carcinoma on his left arm near the elbow is described; microscopic evaluation of the biopsy tissue specimen shows not only nodular aggregates and strands of atypical basaloid tumor cells but also marked deposition of amorphous amyloid material in the stroma between the aggregates of basal cell carcinoma. Including the man in this report, there are additional individual descriptions of patients whose basal cell carcinomas have amyloid deposits in the adjacent stroma or within the tumor aggregates or both. In addition, several retrospective pathology investigations have evaluated the features of this phenomenon. The incidence of basal cell carcinoma with amyloid deposition, in the English literature, ranges from 11% to 75%; however, it is possible that staining technique or tumor subtype or quantity of amyloid present may account for the lower detection of amyloid observed by some of the researchers. Amyloid in basal cell carcinoma specimens was observed to be present more frequently in older patients who had tumors with less aggressive histology patterns. Nodular basal cell carcinoma was the most common subtype of tumor with amyloid deposits whereas superficial basal cell carcinoma was the least frequent subtype. The amyloid deposits were usually identified on hematoxylin and eosin-stained sections and confirmed by using stains that allowed for easier visualization of the amyloid. The amyloid deposits were most commonly located in the stroma between the tumor aggregates; other locations included the papillary dermis above the carcinoma, the dermis at the advancing edge of the tumor and within the aggregates of basal cell carcinoma. Many of the basal cell carcinomas with amyloid deposits, similar to the reported patient, also contained solar elastosis. The origin of the amyloid deposition in these tumors is secondary amyloid AA protein from keratin derived from the epithelial cells overlying the basal cell carcinomas. The presence of amyloid deposition does not alter the management of these basal cell carcinomas; the treatment of the tumor is the same as when the basal cell carcinoma does not contain amyloid deposition.