CHSU Discovery

Abstract:

Introduction: Acral lentiginous melanoma (ALM) is an uncommon subtype of melanoma found in nails, palms, and soles that often results in poor prognosis due to due delays in diagnosis (Zell). ALM typically presents as a pigmented papule with irregular borders with variegated pigment, which may become large, exophytic and nodular with black-blue pigmented areas (Soon). Thus, ALM may be mistaken for other dermatologic conditions including warts, fungal infection, traumatic wounds, pyogenic granulomas, and hematomas (Soon).Given the challenges of early detection and the relatively worse prognosis, this case report highlights the importance of early screening and treating of ALM. We present a case of a 61 yr old male who presented with a fungating mass on his right heel, pathology confirmed malignant acral melanoma.
Case presentation: 61-year-old male with a past medical history of bronchitis presented to the ED with a fungating mass on his right heel. The patient reported that 1.5 years prior to this hospitalisation, he hurt his foot and developed a small fluid-filled blister on his right heel, following a hiking incident. The patient did not seek medical attention and tried home remedies. Overtime it had progressed to mimic a mushroom like mass with a sausage patty texture. It was tender in the middle and would frequently bleed to the point that it would be hard to take off his shoes as the sole would stick to his foot due to coagulated blood.7 months prior, he got Myiasis in his foot and tried hydrogen peroxide wash. At the time of presentation, the mass gave out a rotten odor and swelling of right lower limb, which urged him to seek medical attention. 
The only medical encounter of note is an ED visit for Sciatica, a year ago, CT of hip joint showed dislocated hip joint.
Hospital course: On admission the patient's WBC count was 15.8, ESR 88 CRP 10.3. He was started on empiric antibiotic therapy, vancomycin IV twice daily and cefepime 2 g IV twice daily, Tissue C/S grew Proteus mirabilis and Staphylococcus simulans and pt. was started on ciprofloxacin 500 mg twice daily based on sensitivity. 

Discussion: Aral lentiginous melanoma (ALM) is the least common subtype of melanoma, comprising only 2-3% of all melanomas (Hall & Rapini). ALM has a higher rate of occurrence in non-white populations who are less prone to UV-induced melanomas (Hall & Rapini). ALM typically presents on the palms, soles, fingers, toes, and nail units. In terms of site distribution, case series in skin of color populations report predominance of plantar over palmar melanoma (approximate ratio, 17:1) and of palmoplantar lesions over subungual lesions (approximate ratio, 4:1) ALM’s are distinguished from cutaneous malignant melanomas (CMM) based on their strong association with nevi on the soles, prior penetrating injury, exposure to agriculture chemicals, and inverse association with smoking (Green et. al.).
Because acral melanoma is not caused by UV radiation, and due to the disproportionate distribution of the incidence of acral melanoma among people of color. 
Because of the challenging nature of ALM, "CUBED" acronym for foot melanoma suggested by Dr.Ivan R Bristow et al 
C Coloured lesions where any part is not skin colour.
U Uncertain diagnosis. 
B Bleeding lesions on the foot or under the nail, whether the bleeding is direct bleeding or oozing of fluid. This includes chronic "granulation tissue".
E Enlargement of a lesion or ulcer despite therapy
D Delay in healing of any lesion beyond 2 months.
For that reason, physician's diagnostic skepticism Rodarte should be on high alert to use the CUBED criteria for early referral of ALM cases to avoid any delay that can result in progression of the condition and metastasis.