{'fraction_non_alphanumeric': 0.01882781658062557, 'fraction_numerical': 0.004858791375645309, 'mean_word_length': 5.695121951219512, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Rare Form of Acquired Telangiectasia With Distinctive Histopathologic Features: Answer.

DISCUSSION Cutaneous collagenous vasculopathy (CCV) is a rare form of acquired idiopathic microangiopathy of dermal blood vessels. First described in 2000, fewer than 30 cases have been published till date. Although the first few reported cases involved primarily middle-aged men,1 it has subsequently been recognized that CCV is more common in women.2 It tends to present with asymptomatic blanchable, nonurticated, telangiectatic macules that begin in the lower extremities and progress to involve the trunk and upper extremities. This “upward march” of telangiectasia with relative sparing of the head and neck are useful clinical clues, but a biopsy is essential to establish the diagnosis.3 Although our patient showed this distinctive upward progression over the course of the disease, more significant affection of the forearms rather than the lower extremities was rather unusual. The histopathologic features of CCV are unique and strikingly different from other known telangiectatic conditions in the clinical differential diagnosis, such as generalized essential telangiectasia, which are characterized by dilatation of thinwalled superficial dermal vessels. There is dilatation of the superficial dermal postcapillary venules accompanied by hyaline thickening of the vessel walls. This material reacts strongly with periodic acid–Schiff (diastase resistant), Masson’s trichrome, and antibodies to collagen type IV. Ultrastructurally, this perivascular material can be attributed to deposition of collagen and reduplication of basal lamina. The latter feature is also highlighted on collagen IV immunohistochemistry. Significant dermal inflammation, erythrocyte extravasation, and hemosiderin deposition are not seen.4,5 The etiopathogenesis of CCV is poorly elucidated. The lack of dermal inflammation suggests a nonimmunologically mediated mechanism. It is unclear what initiates damage to the dermal microvasculature or how this leads to collagen deposition around their basal lamina. Loss of pericytes, which normally contain contractile fibrils, results in vascular ectasia. Occlusive microthrombi secondary to endothelial damage has been speculated to be involved in disease progression.5,6 Although unusual, intravascular occlusive fibrin thrombi has been reported in a case of CCV.4 In several case series, a significant number of cases of CCV arose in patients with diabetes mellitus, hypertension, or cardiovascular disease. Because of the high prevalence of these conditions in the general population and the rarity of CCV, this may well be a chance association.5 There is no effective cure for CCV, although cosmetic improvement has been achieved with pulse dye laser, and this woman was referred to plastic surgery for a therapeutic trial.7 In summary, CCV is essentially a histopathological diagnosis with unique microscopic features. Given the perceived low diagnostic yield, a skin biopsy is not routinely performed in all cases of generalized telangiectasia. It is therefore likely that some cases of CCV go unrecognized. A greater awareness among clinicians and pathologists will lead to better recognition and therefore improve our understanding of this unusual condition.