Indian Journal of Dermatopathology and Diagnostic Dermatology

: 2020  |  Volume : 7  |  Issue : 1  |  Page : 33--35

An unusual case of amelanotic melanoma in a young female

Manika Khare, Jai Wade, Abhishek Pareek 
 Department of Pathology and Oncosurgery, Apex Hospitals, Jaipur, Rajasthan, India

Correspondence Address:
Manika Khare
Department of Pathology and Oncosurgery, Apex Hospitals, Jaipur, Rajasthan

How to cite this article:
Khare M, Wade J, Pareek A. An unusual case of amelanotic melanoma in a young female.Indian J Dermatopathol Diagn Dermatol 2020;7:33-35

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Khare M, Wade J, Pareek A. An unusual case of amelanotic melanoma in a young female. Indian J Dermatopathol Diagn Dermatol [serial online] 2020 [cited 2022 Aug 12 ];7:33-35
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Cutaneous melanoma represents a very aggressive type of cancer, which has the fastest-growing incidences worldwide. The clinical presentation of this neoplasm varies widely, from a typically pigmented macular or nodular lesion to a nonpigmented neoplasm that may be solitary or multiple, primary or metastatic.[1] Amelanotic melanoma (AM) accounts for 2%–8% of all melanomas[2] and represents an atypical form of presentation that may not be easily recognized as malignant melanoma due to lack of pigmentation. We are presenting a case of AM in a young female with an interesting diagnostic history.

A 20-year-old female came to the surgery department with a multinodular swelling in the occipital region since 5 months. The swelling was associated with multiple cervical lymphadenopathies [Figure 1]. The patient had a history of the swelling at the same site 2 years back for which she underwent two excision surgeries. In both surgeries, histopathological report showed a diagnosis of squamous cell carcinoma. Hematological and biochemistry parameters of the patient were within normal limits. Surgery of the patient was planned, and we received a specimen of wide local excision of swelling along with nodule over the previous scar long with many cervical lymph nodes. Grossly, the primary specimen was partially skin covered and was measuring 8 cm × 6 cm × 2.5 cm. Cut section showed a gray-white tumor measuring 7 cm × 4 cm × 3 cm. Grossly, all resection margins were unremarkable. Microscopic examination showed a tumor in subepithelial region arranged in sheets, cords, and lobular pattern. Cells showed moderate pleomorphism, clear to eosinophilic cytoplasm, and at places prominent nucleoli [Figure 2]. Foci of spindilisation of the tumor cells were also noted. Large areas of necrosis were seen including comedo necrosis (0/70) lymph nodes were identified; all were free of tumor and showed features of reactive hyperplasia. Based on the above findings possibility of sarcomatoid carcinoma and sebaceous carcinoma were kept in the differential diagnosis. Immunohistochemistry was applied, which showed that tumor cells were positive for epithelial membrane antigen [Figure 3], focal positive for CK5/6 [Figure 4], and negative for CK7 [Figure 5]. Based on above findings, the diagnosis of sarcomatoid carcinoma was given. The patient came back after recurrent nodule at the site of the surgery. Fine-needle aspiration cytology form the same site was done which showed cellular smears with tumor cells arranged in clusters and at places lying singly. Cells were showing large prominent eosinophilic nucleoli, and the possibility of AM was considered [Figure 6]. Immunohistochemistry for the same was done, and tumor cells showed strong positivity for HMB45 [Figure 7]. Prior malignant melanoma was not kept in the differentials because pigment was not identified in the tumor, and AM is very rare; second, tumor origin from the epidermis was not identified in the sections examined. Hence, based on the above findings, the final diagnosis of AM was given.{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}{Figure 6}{Figure 7}

Malignant melanoma mainly arises in the skin. It represents the leading cause of death from cutaneous malignancies.[2],[3] AM usually occurs in sun-exposed skin of elderly with photodamage, simulating various skin lesions. It can also be an exophytic nodule, often eroded.[3] Histopathologically, AM is very difficult to diagnose for its capacity for histomorphological diversity and the ability to mimic a number of nonmelanocytic neoplasms.[4] In our case, the tumor showed histomorphological similarities with sarcomatoid carcinoma and sebaceous carcinoma, tumor was negative for CK7 which helped in ruling out sebaceous carcinoma and showed just focal positivity for CK5/6, excluding the diagnosis of sarcomatoid carcinoma.

Many hypothesis have been proposed to explain the lack of pigment in AM, such as lack of tyrosinase, agenesis of melanosomes, undetectable levels of melanin production, or abnormal melanogenesis.[5] Australian Health Management appears usually in older individuals, preferably on trunk in men and limbs in women. It can appear as nodular or superficial spreading melanoma which was unusual for our case as the lesion was present in a young female.

Termed AM, these lesions tend to have a worse prognosis because of delayed diagnosis and treatment.

Amelanotic variant has a worse prognosis because it exhibits a more aggressive biology and because of difficulty in diagnosis which leads to delayed treatment. At times, cytological findings can be a great aid in making the diagnosis. The early diagnosis of AM can be made with the help of immunohistochemistry panel to rule out the other differentials and to confirm the diagnosis.

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.

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Conflicts of interest

There are no conflicts of interest.


1Batsakis JG. Pathology of tumors of the oral cavity. In: Thawley SE, Panje WR, Batsakis JG, Lindberg RD, editors. Comprehensive Management of Head and Neck Tumors. Philadelphia: W B Saunders; 1987. p. 499-502.
2Balch CM, Milton GW. Cutaneous melanoma. Clinical management and treatment results worldwide. Philadelphia, PA: Lippincott: 1985.
3Bethesda. 1987 Annual Cancer Review. NIH Pub No 88-89, 1987.
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