A 57-year-old woman presented with periorbital ecchymoses, laxity in skin folds, polyneuropathy and bilateral carpal tunnel syndrome. A skin biopsy of the axillary lesion demonstrated fragmentation of elastic fibers, but with a negative von Kossa stain, consistent with cutis laxa. The diagnosis of primary systemic amyloidosis was made by the presence of amyloid material in the eyelid using histopathological techniques, besides this, the patient was also diagnosed with purpura, polyneuropathy, bilateral carpal tunnel syndrome and monoclonal gammopathy. She was diagnosed as suffering from multiple myeloma based on the finding of 40% plasma cells in the bone marrow, component M in the urine and anemia. The patient developed blisters with a clear content, confirmed as mucinosis by the histopathological exam. The final diagnoses were: primary systemic amyloidosis, acquired cutis laxa and mucinosis, all related to multiple myeloma.

Improvement of laboratory diagnosis of onychomychosis is important so that adequate treatment can be safely implemented. To evaluate and compare the performance of mycological and histopathological examinations in onychomycoses caused by dermatophyte and non-dermatophyte moulds. Patients with lateral/distal subungual onychomycosis in at least one hallux were enrolled in the protocol and assessed via mycological and histopathological tests. The isolation of filamentous fungi was considered the gold standard. Test performance was evaluated through sensitivity, specificity and positive and negative predictive values. A total of 212 patients were enrolled in the study. Direct microscopy (DM) was positive in 57.5% patients, and cultures in 34.4%. Among these patients, 23.3% were positive for dermatophytes, with Trichophyton rubrum the most frequently isolated, and 86.3% were positive for non-dermatophytes, with Neoscytalidium dimidiatum predominance. Histopathology was positive in 41.0% samples. Direct microscopy showed better sensitivity for non-dermatophyte moulds (P=.000) and nail clipping was more specific for dermatophyte (P=.018). Histopathology of the distal nail plate is a valuable complementary tool for the diagnosis of onychomycosis caused by dermatophytes and direct microscopy is especially useful for non-dermatophyte molds.

The acral melanoma is the most prevalent type of melanoma in the non-Caucasian population, and dermoscopy is a useful tool for earlier diagnosis and differentiation from benign lesions. The dermoscopic pattern often associated with melanoma on the volar skin is the parallel ridge, with 99% specificity according to the literature. However, this pattern can also occur in several benign acral lesions, so it is important to make a good interpretation of this pattern, along with the clinical history and evolution.

Telangiectasia macularis eruptiva perstans is a rare form of cutaneous mastocytosis, characterized by the presence of erythematous or yellowish-brown macules with telangiectasias, preferably located on the trunk and upper limbs. We have described a case of telangiectasia macularis eruptiva perstans focusing on the dermoscopic characteristics of this disease.

Lichen sclerosus is a chronic inflammatory mucocutaneous disorder of unknown etiology that most commonly affects the female genitalia. Cutaneous involvement with nonhaemorrhagic bullous is very unusual. We describe a case of bullous lichen sclerosus.

Muir-Torre syndrome is a rare genodermatosis characterized by the occurrence of at least one sebaceous tumor associated with visceral neoplasia, but with no predisposing factors. The sebaceous neoplasm may appear before, during or after the diagnosis of colorectal cancer. As it is regarded as a subtype of nonpolyposis hereditary colorectal cancer, it is important to evaluate the patient's first-degree relatives. The clinical course of the neoplasm is usually more indolent and the syndrome has a good prognosis. We report the case of a patient who, after a ten-year diagnosis of colorectal cancer, presented with multiple sebaceous neoplasms.