A B S T R A C T

SKIN AND SKELETAL MUSCLEMETASTASIS OF ADENOCARCINOMA

OF RECTUM: AN UNUSUALMANIFESTATION

Key words Adenocarcinoma rectum, Metastasis- adenocarcinoma rectum.

MUTAHIR ALI TUNIO, ALTAF HASHMI, MUHAMMAD MUBARIK

INTRODUCTION:The true incidence of rectal cancer in Pakistan is notknown but reported data shows similarity with otherAsian and Middle East countries though it is muchlower than reported from the developed countries. A41% rise in incidence was noted in Pakistani malesduring the period of late 90’s, which may indicate ahigher risk in males in the future. Unfortunately mostrectal cancers present at metastatic stages in ourregion, and are not amenable to upfront curativesurgery.2 Metastasis from rectal adenocarcinoma canoccur by lymphatic, haematogenous, direct orperitoneal spread. The most common sites ofcolorectal metastasis are the liver and lung.3

Involvement of the skin and skeletal muscles arequite rare and occur in 4% of all patients withdiagnosis of rectal cancer.4 The prognosis in suchpatients is usually very dismal.5 We report a veryrare case of metastatic spread to rare sites in apatient with adenocarcinoma.

CASE REPORT:A 17 years old male underwent abdominoperinealresection for a low lying rectal cancer 6 cm from theanal verge. His preoperative radiological staging wasT3N0M0. The postoperative histopathological findingswere poorly differentiated adenocarcinoma with

Correspondence:Dr. Mutahir A. TunioDepartment of Radiation OncologySindh Institute of Urology & TransplantationKarachi.E mail: drmutahirtonio@hotmail.com

perineural invasion, lymphovascular involvement andpositive circumferential margins. The proximal anddistal margins were negative. Two out of 15 dissectedlymph nodes were posi t ive for mal ignancy(pT3N1M0). After the surgery, he underwentpostoperative chemoradiation {50.4 Grays (Gy); 1.8Gy/faction/day; 5 fractions per week with 5-flourouracilas continuous venous infusion} from October toDecember 2008.

Eight months later he presented in oncology clinicwith two months history of multiple painless skinnodules over the face on right side, abdomen andperineum. He also complained of left buttock painand one episode of gross haematuria. On generalphysical examination, patient was emaciated andanaemic. Multiple small erythematous skin nodulesof various sizes were noted on face, chest, abdomenand perineum. Largest one was on the left buttockof size 2 cm x 2 cm which was hard in consistencylike other nodules. On further examination, diffusetender swelling was noticed in left buttock of size 10x 18 cm (Fig-I).

Computed tomography (CT) revealed a diffuse massin left gluteal muscles with loss of subcutaneous fatplanes and skin nodules (Fig-II). Additional findingswere presacral mass which involved the seminalvesicles and urinary bladder. However liver and lungswere negative for metastatic disease. A provisionaldiagnosis of recurrent rectal adenocarcinoma wasmade. The excisional biopsies of skin nodules andincisional biopsies of left gluteal muscles wereperformed. Histopathology was consistent with

The frequency of rectal cancer in Pakistan appears to be similar to those in other Asiancountries, but much lower than in the developed countries. Most rectal cancers presentat advanced stages, and are not amenable to upfront curative surgery. Adenocarcinomaof rectum most frequently metastasizes to the liver, lungs and skin. Skeletal musclemetastasis is a rare presentation. Herein, a rare case of skin and gluteus maximus musclemetastases of adenocarcinoma rectum in a 17 years old male is reported.

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metastatic adenocarcinoma, rectal in origin (Fig-III).

He was given palliative radiotherapy to presacralrecurrence and left gluteal muscles metastasis, 30Gy in ten fractions for pain control. Subsequentlypalliative chemotherapy was started. Patient livedthree months from date of diagnosis of metastaticdisease in skin and muscles.

DISCUSSION:Skin and skeletal muscles metastases arising fromadenocarcinoma of rectum are rare with poorsurvival.4,5 However our patient presented as isolatedskin and skeletal muscle metastases without anyliver or lung metastasis. The most frequent regionof skin metastasis in colorectal cancer is abdomen,especially in the postoperative abdominoperinealresection scars, occurring in up to 0.6% of allpatients. According to the data of one of the largestreviews of colorectal skin metastases, in 3 (3.9%)out of 77 patients they occurred at the site ofpostoperative scar. 6

The possible mechanism of metastatic spread ofadenocarcinoma of rectum to the skin and skeletalmuscles could be by lymphatics, haematogenousroute, direct extension of primary disease and bymanipulation during surgery.7 In our patient, perinealskin and gluteal muscle metastases could be dueto surgical implantation. Having obtained clear lateralmargins at the initial surgery, the metastases werelikely to have been secondary to the seeding ofexfoliated tumour cells during tumour mobilisation.8

Skin and skeletal muscle metastases are commonlythought to be associated with poor average survivalbecause of underlying widespread disease, with anaverage of 3.3 months after diagnosis; it warrantsaggressive surgical resection, radiotherapy and theuse of systemic chemotherapy.9 Our patient alsoreceived palliative treatment but he could not survive.Clinicians thus must be aware of this mode ofmetastasis and perform careful examination forprompt diagnosis which may affect the outcome.

REFERENCES:

1. Bhurgri Y, Bhurgri A, Nishter S, Ahmed A,Usman A, Pervez S, et al. Pakistan-countryprofile of cancer and cancer control 1995-2004. J Pak Med Assoc 2006; 56:124-30.

2. Tunio MA, Rafi M, Hashmi A, Mohsin R,Qayyum A, Hasan M,et al. High-dose-ratei n t r a l u m i n a l b r a c h y t h e r a p y d u r i n gpreoperative chemoradiation for locallyadvanced rec ta l cancers . Wor ld JG a s t r o e n t e r o l 2 0 1 0 ; 1 6 : 4 4 3 6 - 4 2 .

3. Attili VS, Rama CC, Dadhich HK, Sahoo TP,Anupama G, Bapsy PP. Unusual metastasisin colorectal cancer. Indian J Cancer2006;43:93-5.

4. Warchol R, Szymanski L, Seichter A. Rectal

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Mutahir Ali Tunio, Altaf Hashmi, Muhammad Mubarik

Fig II: CT scan showing skin nodulesand left gluteal muscles mass.

Fig III: Histopathology was consistent withmetastatic adenocarcinoma primaryrectum

Fig I: Multiple skin nodules over the face,abdomen and perineum.

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adenocarcinoma metastasis to the facialskin--case report. Otolaryngol Pol 2008;62:96-9.

5. Kaytan E, Karadeniz A, Alici S, Fayda M,Kizir A. Unusual metastases from rectaladenocarcinoma; report of two cases withl i te ra ture rev iew. 2002; 7 :377-80.

6. Saeed S, Keehn CA, Morgan MB. Cutaneousmetastasis: a clinical, pathological, andimmunohistochemical appraisal. J CutanPathol 2004, 31:419-30.

7. Tan KY, Ho KS, Lai JH, Lim JF, Ooi BS, TangCL, et al. Ann Acad Med Singapore 2006;35:585-7.

8. De Friend DJ, Kramer E, Prescott R, CorsonJ, Gal lagher P. Cutaneous per ianalrecurrence of cancer after anterior resectionusing the EEA stapling device. Ann R CollSurg Engl 1992; 74:142-3.

9. Araki K, Kobayashi M, Ogata T, Takuma K.Hepatogastroenterology 1994; 41:405-8

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