Sebaceous gland tumors are rare and their presence should alert the physician to search for internal malignancies. These malignancies may appear before, concomitantly or even few years after the appearance of cutaneous lesions. We are reporting a case of sebaceous gland adenoarcinoma who clinically presented with infected sebaceous cyst and final diagnosis of adenocarcinoma was made on histopathological examination. This patient is put on close surveillance for the detection of internal malignancies.
Sebaceous gland tumors are rare and their presence should be considered as a marker of Muir-Torr syndrome [1]. This syndrome is defined as the combination of a sebaceous gland tumour and at least one visceral carcinoma in the absence of other precipitating factors such as radiotherapy or AIDS [2]. Skin lesions may occur before the presentation of internal malignancies, but usually occur later or concomitantly.
Case Presentation
A 45 year old male patient presented with a swelling of 5 x 7cm on the left lateral side of the upper chest with yellowish color discharge for the last 3 months. Clinical diagnosis of infected sebaceous cyst was made and incision and drainage was carried out along with the biopsy of the wall as there was hard mass suspicious of malignancy. Biopsy revealed sebaceous adenocarcinoma. Patient was investigated for any other visceral malignancy. Chest X-ray, USG Abdomen, Urinary cytology, Tumor markers (CA19-9 and CEA) and colonoscopy were found to be normal. Detailed family history was obtained but could not reveal any history of malignancy.
Wide local excision with a 2cm margin all around and axillary lymphnode dissection was done under general anaesthesia. Skin could not be approximated and the defect was closed with the help of Split thickness skin graft. Histopathology was consistent with the previous biopsy of adenocarcinoma with the metastatic deposits in two lymphnodes.
Patient was referred to the medical oncologist for the chemoradiation after proper healing of the wound.
Discussion
Sebaceous carcinoma is a rare aggressive tumor derived from the adenexal epithelium of sebaceous gland, accounting for less than 1% of all cutaneous malignancies [3]. Sebaceous carcinoma is traditionally classified into two groups: tumors arising from the ocular adenexa (the meibomian glands and glands of zeiss) and those arising from extraocular sites. Extraocular sebaceous carcinomas most commonly involve the head and neck region, where sebaceous glands are more plentiful, followed by external genitalia though the tumor may arise anywhere in the body where these glands exist [4]. This is true in our case as the lateral upper chest wall is an unusual site for this tumor.
Sebaceous carcinoma may appear in thebackground of preexisting dermatoses like naevus sebaceous and actinic keratosis or may follow radiation therapy for other diseases. It may also occur in Muir-Torre syndrome, a cancer associated genodermatoses, defined by the combination of sebaceous gland tumor ( adenoma, epithelioma or carcinoma) and at least one visceral carcinoma occurring in the same individual in the absence of precipitating factors such as radiotherapy or AIDS [2].
Figure 1 Split thickness skin graft after wide local excision of the tumor.
Figure 1 Split thickness skin graft after wide local excision of the tumor.
The sex distribution of extraocular sebaceous carcinoma appears to be equal in male and female with the mean age of occurrence being 63 years [3]. The malignancy occurred in our patient at an early age of 45 years.
Sebaceous gland tumors are rare and their presence should alert the physician to search for internal malignancies [1]. Skin lesions may precede the presentation of an internal malignancy but may develop later. Fifty six percent of skin lesions occur after the diagnosis of first malignancy, six percent occur concomitantly and twenty two percent occur as the first malignancy of the syndrome [5]. The cutaneous lesion may occur as much as 25 years before or 37 years after the internal malignancy [6]. We could not find any evidence of either previous or concomitant internal malignancy, and put the patient on regular surveillance.
Screening of malignancies at all possible sites is not practically possible and should probably concentrate on colorectal, urinary tract and female genital tract [7]. Colorectal cancer is the commonest visceral neoplasm associated with Muir-Torre syndrome and the most frequent initial cancer also. The second most common site is genitourinary tract [8,9]. Cohen et al. suggested that the search for internal malignancies should be undertaken in those with MTS associated sebaceous gland tumor, those with MTS and in the family members of MTS patient. They also suggested a surveillance program for these patients including annual clinical examination, carcinoembryonic antigen, cervical smear, chest radiography, urine cytology, colonoscopy or barium enema every 3-5 years and mammography 1-2 yearly till the age of 50 and then annually [9]. Others have suggested more frequent colonoscopic examination, annually from the age of 25years owing to the high frequency of colonic cancers [8].
Histopathologically sebaceous carcinomas are often poorly differentiated neoplasms mainly with in the dermis. The histological criteria for sebaceous carcinoma are high mitotic activity, nuclear pleomorphism, lobular architecture and foamy vacuolization of the cytoplasm [10].
Despite poorly differentiated neoplasm histopathologically, they have a good prognosis and non aggressive course and the surgical removal of primary or metastatic carcinoma is strongly advisable wherever possible [5,11]. Complete excision of the tumor was done in our case along with the regional lymph node dissection. There are diverse opinions regarding the use of post operative irradiation and chemotherapy [4].
Sebaceous gland carcinoma is rare and the diagnosis of this tumor should suggest the possibility of Muir-Torre syndrome and prompt a search for underlying malignancies. Patient should be put on regular surveillance even if the search for the internal malignancies are negative as they can appear later in the life.